CMP Journal 2025-05-21
Statistics
Nature: 20
Nature Nanotechnology: 1
Nature Physics: 2
Nature Reviews Materials: 1
Physical Review Letters: 20
Physical Review X: 2
arXiv: 75
Nature
Unravelling cysteine-deficiency-associated rapid weight loss
Original Paper | Fat metabolism | 2025-05-20 20:00 EDT
Alan Varghese, Ivan Gusarov, Begoña Gamallo-Lana, Daria Dolgonos, Yatin Mankan, Ilya Shamovsky, Mydia Phan, Rebecca Jones, Maria Gomez-Jenkins, Eileen White, Rui Wang, Drew R. Jones, Thales Papagiannakopoulos, Michael E. Pacold, Adam C. Mar, Dan R. Littman, Evgeny Nudler
Around 40% of the US population and 1 in 6 individuals worldwide have obesity, with the incidence surging globally1,2. Various dietary interventions, including carbohydrate, fat and, more recently, amino acid restriction, have been explored to combat this epidemic3,4,5,6. Here we investigated the impact of removing individual amino acids on the weight profiles of mice. We show that conditional cysteine restriction resulted in the most substantial weight loss when compared to essential amino acid restriction, amounting to 30% within 1 week, which was readily reversed. We found that cysteine deficiency activated the integrated stress response and oxidative stress response, which amplify each other, leading to the induction of GDF15 and FGF21, partly explaining the phenotype7,8,9. Notably, we observed lower levels of tissue coenzyme A (CoA), which has been considered to be extremely stable10, resulting in reduced mitochondrial functionality and metabolic rewiring. This results in energetically inefficient anaerobic glycolysis and defective tricarboxylic acid cycle, with sustained urinary excretion of pyruvate, orotate, citrate, α-ketoglutarate, nitrogen-rich compounds and amino acids. In summary, our investigation reveals that cysteine restriction, by depleting GSH and CoA, exerts a maximal impact on weight loss, metabolism and stress signalling compared with other amino acid restrictions. These findings suggest strategies for addressing a range of metabolic diseases and the growing obesity crisis.
Fat metabolism, Metabolomics, Mitochondria
A retrograde planet in a tight binary star system with a white dwarf
Original Paper | Exoplanets | 2025-05-20 20:00 EDT
Ho Wan Cheng, Trifon Trifonov, Man Hoi Lee, Faustine Cantalloube, Sabine Reffert, David Ramm, Andreas Quirrenbach
Close-in companion stars are expected to adversely influence the formation and orbital stability of circumstellar (S-type) planets by tidally truncating protoplanetary discs1,2,3,4, impeding mutual accretion of planetesimals5,6,7,8 and narrowing dynamically stable regions9. This explains the observed dearth of S-type planets in tight binary star systems10,11,12,13. ν Octantis, whose stellar components have a mean separation of 2.6 au, has long been suspected of hosting a circum-primary planet in a retrograde and exceptionally wide orbit that resides midway between the stars14,15,16,17,18,19,20. Strong theoretical grounds against its formation and the absence of observational precedents, however, have challenged the reality of the planet. Here we present new radial velocity measurements that consolidate the planet hypothesis. Stable fits to all radial velocity data require the planetary orbit to be retrograde and practically coplanar. We also report the critical discovery from adaptive optics imaging that the companion star is a white dwarf. Our exploration of credible primordial binary orbital settings shows that the minimum separation between the stars was 1.3 au initially, which overlaps the current planetary orbit and makes any scenarios in which the circum-primary planetary orbit formed coevally with the young stars hardly conceivable. The retrograde planet must have originated from a circumbinary orbit or a second-generation protoplanetary disc, showing the role of binary stellar evolution in the formation and evolution of planetary systems.
Exoplanets
Clonal tracing with somatic epimutations reveals dynamics of blood ageing
Original Paper | Haematopoietic stem cells | 2025-05-20 20:00 EDT
Michael Scherer, Indranil Singh, Martina Maria Braun, Chelsea Szu-Tu, Pedro Sanchez Sanchez, Dominik Lindenhofer, Niels Asger Jakobsen, Verena Körber, Michael Kardorff, Lena Nitsch, Pauline Kautz, Julia Rühle, Agostina Bianchi, Luca Cozzuto, Robert Frömel, Sergi Beneyto-Calabuig, Caleb Lareau, Ansuman T. Satpathy, Renée Beekman, Lars M. Steinmetz, Simon Raffel, Leif S. Ludwig, Paresh Vyas, Alejo Rodriguez-Fraticelli, Lars Velten
Current approaches used to track stem cell clones through differentiation require genetic engineering1,2 or rely on sparse somatic DNA variants3,4, which limits their wide application. Here we discover that DNA methylation of a subset of CpG sites reflects cellular differentiation, whereas another subset undergoes stochastic epimutations and can serve as digital barcodes of clonal identity. We demonstrate that targeted single-cell profiling of DNA methylation5 at single-CpG resolution can accurately extract both layers of information. To that end, we develop EPI-Clone, a method for transgene-free lineage tracing at scale. Applied to mouse and human haematopoiesis, we capture hundreds of clonal differentiation trajectories across tens of individuals and 230,358 single cells. In mouse ageing, we demonstrate that myeloid bias and low output of old haematopoietic stem cells6 are restricted to a small number of expanded clones, whereas many functionally young-like clones persist in old age. In human ageing, clones with and without known driver mutations of clonal haematopoieis7 are part of a spectrum of age-related clonal expansions that display similar lineage biases. EPI-Clone enables accurate and transgene-free single-cell lineage tracing on hematopoietic cell state landscapes at scale.
Haematopoietic stem cells, Methylation analysis
Programmable control of spatial transcriptome in live cells and neurons
Original Paper | Cellular imaging | 2025-05-20 20:00 EDT
Mengting Han, Maylin L. Fu, Yanyu Zhu, Alexander A. Choi, Emmy Li, Jon Bezney, Sa Cai, Leann Miles, Yitong Ma, Lei S. Qi
Spatial RNA organization has a pivotal role in diverse cellular processes and diseases1,2,3,4. However, functional implications of the spatial transcriptome remain largely unexplored due to limited technologies for perturbing endogenous RNA within specific subcellular regions1,5. Here we present CRISPR-mediated transcriptome organization (CRISPR-TO), a system that harnesses RNA-guided, nuclease-dead dCas13 for programmable control of endogenous RNA localization in live cells. CRISPR-TO enables targeted localization of endogenous RNAs to diverse subcellular compartments, including the outer mitochondrial membrane, p-bodies, stress granules, telomeres and nuclear stress bodies, across various cell types. It allows for inducible and reversible bidirectional RNA transport along microtubules via motor proteins, facilitating real-time manipulation and monitoring of RNA localization dynamics in living cells. In primary cortical neurons, we demonstrate that repositioned mRNAs undergo local translation along neurites and at neurite tips, and co-transport with ribosomes, with β-actin mRNA localization enhancing the formation of dynamic filopodial protrusions and inhibiting axonal regeneration. CRISPR-TO-enabled screening in primary neurons identifies Stmn2 mRNA localization as a driver of neurite outgrowth. By enabling large-scale perturbation of the spatial transcriptome, CRISPR-TO bridges a critical gap left by sequencing and imaging technologies, offering a versatile platform for high-throughput functional interrogation of RNA localization in living cells and organisms.
Cellular imaging, Molecular neuroscience, RNA, Synthetic biology, Transcriptomics
Large gas inflow driven by a matured galactic bar in the early Universe
Original Paper | Early universe | 2025-05-20 20:00 EDT
Shuo Huang, Ryohei Kawabe, Hideki Umehata, Kotaro Kohno, Yoichi Tamura, Toshiki Saito
Bar structures are present in about half of local disk galaxies1 and play pivotal roles in secular galaxy evolution. Bars impose a non-axisymmetric perturbation on the rotating disk and transport gas inwards to feed the central starburst and, possibly, the activity of the nuclear supermassive black hole2. They are believed to be long-lived structures3,4 and are now identified at redshift z > 2 (refs. 5,6). However, little is known about the onset and effects of bars in the early cosmic epoch because the spectroscopy of distant bars at sufficient resolution is prohibitively expensive. Here we report on a kinematic study of a galactic bar at redshift 2.467, 2.6 billion years after the Big Bang. We observed the carbon monoxide and atomic carbon emission lines of the dusty star-forming galaxy J0107a and found the bar of J0107a has gas distribution and motion in a pattern identical to local bars7,8,9. At the same time, the bar drives large-scale non-circular motions that dominate over disk rotation, funnelling molecular gas into its centre at a rate of approximately 600 solar masses per year. Our results show that bar-driven dynamical processes and secular evolution were already at play 11.1 billion years ago, powering active star formation amid the gas-rich and far-infrared luminous growth phase in a massive disk galaxy.
Early universe, Galaxies and clusters, Interstellar medium
Quasar radiation transforms the gas in a merging companion galaxy
Original Paper | Galaxies and clusters | 2025-05-20 20:00 EDT
Sergei Balashev, Pasquier Noterdaeme, Neeraj Gupta, Jens-Kristian Krogager, Françoise Combes, Sebastián López, Patrick Petitjean, Alain Omont, Raghunathan Srianand, Rodrigo Cuellar
Quasars, powered by gas accretion onto supermassive black holes1,2, rank among the most energetic objects in the Universe3,4. Although they are thought to be ignited by galaxy mergers5,6,7,8,9,10,11 and affect the surrounding gas12,13,14,15, observational constraints on both processes remain scarce16,17,18. Here we describe a major merging system at redshift z ≈ 2.7 and demonstrate that radiation from the quasar in one galaxy directly alters the gas properties in the other galaxy. Our findings reveal that the galaxies, with centroids separated by only a few kiloparsecs and approaching each other at a speed of approximately 550 km s-1, are massive, are forming stars and contain a substantial molecular mass. Yet, dusty molecular gas seen in absorption against the quasar nucleus is highly excited and confined within cloudlets with densities of approximately 105 to 106 cm-3 and sizes of less than 0.02 pc, several orders of magnitude more compact than those observed in intervening (non-quasar) environments. This is also approximately 105 times smaller than currently resolvable through molecular-line emission at high redshifts. We infer that, wherever it is exposed to the quasar radiation, the molecular gas is disrupted, leaving behind surviving dense clouds too small to give birth to new stars. Our results not only underscore the role of major galaxy mergers in triggering quasar activity but also reveal localized negative feedback as a profound alteration of the internal gas structure, which probably hampers star formation.
Galaxies and clusters, Interstellar medium
Closed-loop vagus nerve stimulation aids recovery from spinal cord injury
Original Paper | Diseases of the nervous system | 2025-05-20 20:00 EDT
Michael P. Kilgard, Joseph D. Epperson, Emmanuel A. Adehunoluwa, Chad Swank, Amy L. Porter, David T. Pruitt, Holle L. Gallaway, Christi Stevens, Jaime Gillespie, Dannae Arnold, Mark B. Powers, Rita G. Hamilton, Richard C. Naftalis, Michael L. Foreman, Jane G. Wigginton, Seth A. Hays, Robert L. Rennaker
Decades of research have demonstrated that recovery from serious neurological injury will require synergistic therapeutic approaches. Rewiring spared neural circuits after injury is a long-standing goal of neurorehabilitation1,2. We hypothesized that combining intensive, progressive, task-focused training with real-time closed-loop vagus nerve stimulation (CLV) to enhance synaptic plasticity3 could increase strength, expand range of motion and improve hand function in people with chronic, incomplete cervical spinal cord injury. Here we report the results from a prospective, double-blinded, sham-controlled, randomized study combining gamified physical therapy using force and motion sensors to deliver sham or active CLV (ClinicalTrials.gov identifier NCT04288245). After 12 weeks of therapy composed of a miniaturized implant selectively activating the vagus nerve on successful movements, 19 people exhibited a significant beneficial effect on arm and hand strength and the ability to perform activities of daily living. CLV represents a promising therapeutic avenue for people with chronic, incomplete cervical spinal cord injury.
Diseases of the nervous system, Motor control
The structure of liquid carbon elucidated by in situ X-ray diffraction
Original Paper | Characterization and analytical techniques | 2025-05-20 20:00 EDT
D. Kraus, J. Rips, M. Schörner, M. G. Stevenson, J. Vorberger, D. Ranjan, J. Lütgert, B. Heuser, J. H. Eggert, H.-P. Liermann, I. I. Oleynik, S. Pandolfi, R. Redmer, A. Sollier, C. Strohm, T. J. Volz, B. Albertazzi, S. J. Ali, L. Antonelli, C. Bähtz, O. B. Ball, S. Banerjee, A. B. Belonoshko, C. A. Bolme, V. Bouffetier, R. Briggs, K. Buakor, T. Butcher, V. Cerantola, J. Chantel, A. L. Coleman, J. Collier, G. W. Collins, A. J. Comley, T. E. Cowan, G. Cristoforetti, H. Cynn, A. Descamps, A. Di Cicco, S. Di Dio Cafiso, F. Dorchies, M. J. Duff, A. Dwivedi, C. Edwards, D. Errandonea, S. Galitskiy, E. Galtier, H. Ginestet, L. Gizzi, A. Gleason, S. Göde, J. M. Gonzalez, M. G. Gorman, M. Harmand, N. J. Hartley, P. G. Heighway, C. Hernandez-Gomez, A. Higginbotham, H. Höppner, R. J. Husband, T. M. Hutchinson, H. Hwang, D. A. Keen, J. Kim, P. Koester, Z. Konôpková, A. Krygier, L. Labate, A. Laso Garcia, A. E. Lazicki, Y. Lee, P. Mason, M. Masruri, B. Massani, E. E. McBride, J. D. McHardy, D. McGonegle, C. McGuire, R. S. McWilliams, S. Merkel, G. Morard, B. Nagler, M. Nakatsutsumi, K. Nguyen-Cong, A.-M. Norton, N. Ozaki, C. Otzen, D. J. Peake, A. Pelka, K. A. Pereira, J. P. Phillips, C. Prescher, T. R. Preston, L. Randolph, A. Ravasio, D. Santamaria-Perez, D. J. Savage, M. Schölmerich, J.-P. Schwinkendorf, S. Singh, J. Smith, R. F. Smith, J. Spear, C. Spindloe, T.-A. Suer, M. Tang, M. Toncian, T. Toncian, S. J. Tracy, A. Trapananti, C. E. Vennari, T. Vinci, M. Tyldesley, S. C. Vogel, J. P. S. Walsh, J. S. Wark, J. T. Willman, L. Wollenweber, U. Zastrau, E. Brambrink, K. Appel, M. I. McMahon
Carbon has a central role in biology and organic chemistry, and its solid allotropes provide the basis of much of our modern technology1. However, the liquid form of carbon remains nearly uncharted2, and the structure of liquid carbon and most of its physical properties are essentially unknown3. But liquid carbon is relevant for modelling planetary interiors4,5 and the atmospheres of white dwarfs6, as an intermediate state for the synthesis of advanced carbon materials7,8, inertial confinement fusion implosions9, hypervelocity impact events on carbon materials10 and our general understanding of structured fluids at extreme conditions11. Here we present a precise structure measurement of liquid carbon at pressures of around 1 million atmospheres obtained by in situ X-ray diffraction at an X-ray free-electron laser. Our results show a complex fluid with transient bonding and approximately four nearest neighbours on average, in agreement with quantum molecular dynamics simulations. The obtained data substantiate the understanding of the liquid state of one of the most abundant elements in the universe and can test models of the melting line. The demonstrated experimental abilities open the path to performing similar studies of the structure of liquids composed of light elements at extreme conditions.
Characterization and analytical techniques, Core processes, Laboratory astrophysics, Laser-produced plasmas, Structure of solids and liquids
Glioblastoma-instructed astrocytes suppress tumour-specific T cell immunity
Original Paper | Neuroimmunology | 2025-05-20 20:00 EDT
Camilo Faust Akl, Brian M. Andersen, Zhaorong Li, Federico Giovannoni, Martin Diebold, Liliana M. Sanmarco, Michael Kilian, Luca Fehrenbacher, Florian Pernin, Joseph M. Rone, Hong-Gyun Lee, Gavin Piester, Jessica E. Kenison, Joon-Hyuk Lee, Tomer Illouz, Carolina M. Polonio, Léna Srun, Jazmin Martinez, Elizabeth N. Chung, Anton Schüle, Agustin Plasencia, Lucinda Li, Kylynne Ferrara, Mercedes Lewandrowski, Craig A. Strathdee, Lorena Lerner, Christophe Quéva, Iain C. Clark, Benjamin Deneen, Judy Lieberman, David H. Sherr, Jack P. Antel, Michael A. Wheeler, Keith L. Ligon, E. Antonio Chiocca, Marco Prinz, David A. Reardon, Francisco J. Quintana
Glioblastoma is the most common and aggressive primary brain cancer and shows minimal response to therapies. The immunosuppressive tumour microenvironment in glioblastoma contributes to the limited therapeutic response. Astrocytes are abundant in the central nervous system and have important immunoregulatory roles. However, little is known about their role in the immune response to glioblastoma1. Here we used single-cell and bulk RNA sequencing of clinical glioblastoma samples and samples from preclinical models, multiplexed immunofluorescence, in vivo CRISPR-based cell-specific genetic perturbations and in vitro mouse and human experimental systems to address this gap in knowledge. We identified an astrocyte subset that limits tumour immunity by inducing T cell apoptosis through the death receptor ligand TRAIL. Moreover, we identified that IL-11 produced by tumour cells is a driver of STAT3-dependent TRAIL expression in astrocytes. Astrocyte signalling through STAT3 and TRAIL expression were associated with a shorter time to recurrence and overall decreased survival in patients with glioblastoma. Genetic inactivation of the IL-11 receptor or TRAIL in astrocytes extended survival in mouse models of glioblastoma and enhanced T cell and macrophage responses. Finally, treatment with an oncolytic HSV-1 virus engineered to express a TRAIL-blocking single-chain antibody in the tumour microenvironment extended survival and enhanced tumour-specific immunity in preclinical models of glioblastoma. In summary, we establish that IL-11-STAT3-driven astrocytes suppress glioblastoma-specific protective immunity by inducing TRAIL-dependent T cell apoptosis, and engineered therapeutic viruses can be used to target this mechanism of astrocyte-driven tumour immunoevasion.
Neuroimmunology, Tumour immunology
C-to-N atom swapping and skeletal editing in indoles and benzofurans
Original Paper | Diversity-oriented synthesis | 2025-05-20 20:00 EDT
Zhe Wang, Pengwei Xu, Shu-Min Guo, Constantin G. Daniliuc, Armido Studer
Skeletal editing comprises the structural reorganization of compounds. Such editing can be achieved through atom swapping, atom insertion, atom deletion or reorganization of the compound’s backbone structure1,2. Conducted at a late stage in drug development campaigns, skeletal editing enables diversification of an existing pharmacophore, enhancing the efficiency of drug development. Instead of constructing a heteroarene classically from basic building blocks, structural variants are readily accessible directly starting from a lead compound or approved pharmacophore. Here we present C to N atom swapping in indoles at the C2 position to give indazoles through oxidative cleavage of the indole heteroarene core and subsequent ring closure. Reactions proceed through ring-opened oximes as intermediates. These ring deconstructed intermediates can also be diverted into benzimidazoles resulting in an overall C to N atom swapping with concomitant skeletal reorganization. The same structural diverting strategies are equally well applicable to benzofurans leading to either benzisoxazoles or benzoxazoles. The compound classes obtained through these methods–indazoles3,4, benzisoxazoles5, benzimidazoles6,7 and benzoxazoles8–are biologically relevant moieties found as substructures in natural products and pharmaceuticals. The procedures introduced substantially enlarge the methods portfolio in the emerging field of skeletal editing.
Diversity-oriented synthesis, Synthetic chemistry methodology
Stepwise ATP translocation into the endoplasmic reticulum by human SLC35B1
Original Paper | Cryoelectron microscopy | 2025-05-20 20:00 EDT
Ashutosh Gulati, Do-Hwan Ahn, Albert Suades, Yurie Hult, Gernot Wolf, So Iwata, Giulio Superti-Furga, Norimichi Nomura, David Drew
ATP generated in the mitochondria is exported by an ADP/ATP carrier of the SLC25 family1. The endoplasmic reticulum (ER) cannot synthesize ATP but must import cytoplasmic ATP to energize protein folding, quality control and trafficking2,3. It was recently proposed that a member of the nucleotide sugar transporter family, termed SLC35B1 (also known as AXER), is not a nucleotide sugar transporter but a long-sought-after ER importer of ATP4. Here we report that human SLC35B1 does not bind nucleotide sugars but indeed executes strict ATP/ADP exchange with uptake kinetics consistent with the import of ATP into crude ER microsomes. A CRISPR-Cas9 cell-line knockout demonstrated that SLC35B1 clusters with the most essential SLC transporters for cell growth, consistent with its proposed physiological function. We have further determined seven cryogenic electron microscopy structures of human SLC35B1 in complex with an Fv fragment and either bound to an ATP analogue or ADP in all major conformations of the transport cycle. We observed that nucleotides were vertically repositioned up to approximately 6.5 Å during translocation while retaining key interactions with a flexible substrate-binding site. We conclude that SLC35B1 operates by a stepwise ATP translocation mechanism, which is a previously undescribed model for substrate translocation by an SLC transporter.
Cryoelectron microscopy, Endoplasmic reticulum, Permeation and transport
A foundation model for the Earth system
Original Paper | Atmospheric chemistry | 2025-05-20 20:00 EDT
Cristian Bodnar, Wessel P. Bruinsma, Ana Lucic, Megan Stanley, Anna Allen, Johannes Brandstetter, Patrick Garvan, Maik Riechert, Jonathan A. Weyn, Haiyu Dong, Jayesh K. Gupta, Kit Thambiratnam, Alexander T. Archibald, Chun-Chieh Wu, Elizabeth Heider, Max Welling, Richard E. Turner, Paris Perdikaris
Reliable forecasting of the Earth system is essential for mitigating natural disasters and supporting human progress. Traditional numerical models, although powerful, are extremely computationally expensive1. Recent advances in artificial intelligence (AI) have shown promise in improving both predictive performance and efficiency2,3, yet their potential remains underexplored in many Earth system domains. Here we introduce Aurora, a large-scale foundation model trained on more than one million hours of diverse geophysical data. Aurora outperforms operational forecasts in predicting air quality, ocean waves, tropical cyclone tracks and high-resolution weather, all at orders of magnitude lower computational cost. With the ability to be fine-tuned for diverse applications at modest expense, Aurora represents a notable step towards democratizing accurate and efficient Earth system predictions. These results highlight the transformative potential of AI in environmental forecasting and pave the way for broader accessibility to high-quality climate and weather information.
Atmospheric chemistry, Atmospheric dynamics, Computational science
Multigenerational cell tracking of DNA replication and heritable DNA damage
Original Paper | Cell biology | 2025-05-20 20:00 EDT
Andreas Panagopoulos, Merula Stout, Sinan Kilic, Peter Leary, Julia Vornberger, Virginia Pasti, Antonio Galarreta, Aleksandra Lezaja, Kyra Kirschenbühler, Ralph Imhof, Hubert Rehrauer, Urs Ziegler, Matthias Altmeyer
Cell heterogeneity is a universal feature of life. Although biological processes affected by cell-to-cell variation are manifold, from developmental plasticity to tumour heterogeneity and differential drug responses, the sources of cell heterogeneity remain largely unclear1,2. Mutational and epigenetic signatures from cancer (epi)genomics are powerful for deducing processes that shaped cancer genome evolution3,4,5. However, retrospective analyses face difficulties in resolving how cellular heterogeneity emerges and is propagated to subsequent cell generations. Here, we used multigenerational single-cell tracking based on endogenously labelled proteins and custom-designed computational tools to elucidate how oncogenic perturbations induce sister cell asymmetry and phenotypic heterogeneity. Dual CRISPR-based genome editing enabled simultaneous tracking of DNA replication patterns and heritable endogenous DNA lesions. Cell lineage trees of up to four generations were tracked in asynchronously growing cells, and time-resolved lineage analyses were combined with end-point measurements of cell cycle and DNA damage markers through iterative staining. Besides revealing replication and repair dynamics, damage inheritance and emergence of sister cell heterogeneity across multiple cell generations, through combination with single-cell transcriptomics, we delineate how common oncogenic events trigger multiple routes towards polyploidization with distinct outcomes for genome integrity. Our study provides a framework to dissect phenotypic plasticity at the single-cell level and sheds light onto cellular processes that may resemble early events during cancer development.
Cell biology, Cell division, Cellular imaging, DNA damage and repair, DNA replication
Ru and W isotope systematics in ocean island basalts reveals core leakage
Original Paper | Geochemistry | 2025-05-20 20:00 EDT
Nils Messling, Matthias Willbold, Leander Kallas, Tim Elliott, J. Godfrey Fitton, Thomas Müller, Dennis Geist
The isotopic composition of lavas associated with mantle plumes has previously been interpreted in the light of core-mantle interaction, suggesting that mantle plumes may transport core material to Earth’s surface1,2,3,4,5. However, a definitive fingerprint of Earth’s core in the mantle remains unconfirmed. Precious metals, such as ruthenium (Ru), are highly concentrated in the metallic core but extremely depleted in the silicate mantle. Recently discovered mass-independent Ru isotope variations (ε100Ru) in ancient rocks show that the Ru isotope composition of accreted material changed during later stages of Earth’s growth6, indicating that the core and mantle must have different Ru isotope compositions. This illustrates the potential of Ru isotopes as a new tracer for core-mantle interaction. Here we report Ru isotope anomalies for ocean island basalts. Basalts from Hawaii have higher ε100Ru than the ambient mantle. Combined with unradiogenic tungsten (W) isotope ratios, this is diagnostic of a core contribution to their mantle sources. The combined Ru and W isotope systematics of Hawaiian basalts are best explained by simple core entrainment but addition of core-derived oxide minerals at the core-mantle boundary is a possibility.
Geochemistry
PCSK9 drives sterol-dependent metastatic organ choice in pancreatic cancer
Original Paper | Cancer metabolism | 2025-05-20 20:00 EDT
Gilles Rademaker, Grace A. Hernandez, Yurim Seo, Sumena Dahal, Lisa Miller-Phillips, Alexander L. Li, Xianlu Laura Peng, Changfei Luan, Longhui Qiu, Maude A. Liegeois, Bruce Wang, Kwun W. Wen, Grace E. Kim, Eric A. Collisson, Stephan F. Kruger, Stefan Boeck, Steffen Ormanns, Michael Guenther, Volker Heinemann, Michael Haas, Mark R. Looney, Jen Jen Yeh, Roberto Zoncu, Rushika M. Perera
To grow at distant sites, metastatic cells must overcome major challenges posed by the unique cellular and metabolic composition of secondary organs1. Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease that metastasizes to the liver and lungs. Despite evidence of metabolic reprogramming away from the primary site, the key drivers that dictate the ability of PDAC cells to colonize the liver or lungs and survive there remain undefined. Here we identified PCSK9 as predictive of liver versus lung colonization by integrating metastatic tropism data of human PDAC cell lines2, in vivo metastasis modelling in mice and gene expression correlation analysis. PCSK9 negatively regulates low density lipoprotein (LDL)-cholesterol import and, accordingly, PCSK9-low PDAC cells preferentially colonize LDL-rich liver tissue. LDL-cholesterol taken up by liver-avid PCSK9-low cells supports activation of pro-growth mTORC1 activation at the lysosome, and through conversion into the signalling oxysterol, 24(S)-hydroxycholesterol, reprogrammes the microenvironment to release nutrients from neighbouring hepatocytes. Conversely, PCSK9-high, lung-avid PDAC cells rely on transcriptional upregulation of the distal cholesterol synthesis pathway to generate intermediates–7-dehydrocholesterol and 7-dehydrodesmosterol–with protective action against ferroptosis, a vulnerability in the oxygen-rich microenvironment of the lung. Increasing the amount of PCSK9 redirected liver-avid cells to the lung whereas ablating PCSK9 drove lung-avid cells to the liver, thereby establishing PCSK9 as necessary and sufficient for secondary organ site preference. Our studies reveal PCSK9-driven differential utilization of the distal cholesterol synthesis pathway as a key and potentially actionable driver of metastatic growth in PDAC.
Cancer metabolism, Mechanisms of disease
Molecular basis of positional memory in limb regeneration
Original Paper | Cell lineage | 2025-05-20 20:00 EDT
L. Otsuki, S. A. Plattner, Y. Taniguchi-Sugiura, F. Falcon, E. M. Tanaka
The amputation of a salamander limb triggers anterior and posterior connective tissue cells to form distinct signalling centres that together fuel regeneration1. Anterior and posterior identities are established during development and are thought to persist for the whole life in the form of positional memory2. However, the molecular basis of positional memory and whether positional memory can be altered remain unknown. Here, we identify a positive-feedback loop that is responsible for posterior identity in the limb of an axolotl (Ambystoma mexicanum). Posterior cells express residual Hand2 transcription factor from development, and this primes them to form a Shh signalling centre after limb amputation. During regeneration, Shh signalling is also upstream of Hand2 expression. After regeneration, Shh is shut down but Hand2 is sustained, safeguarding posterior memory. We used this regeneration circuitry to convert anterior cells to a posterior-cell memory state. Transient exposure of anterior cells to Shh during regeneration kick-started an ectopic Hand2-Shh loop, leading to stable Hand2 expression and lasting competence to express Shh. Our results implicate positive-feedback in the stability of positional memory and reveal that positional memory is reprogrammed more easily in one direction (anterior to posterior) than in the other. Modifying positional memory in regenerative cells changes their signalling outputs, which has implications for tissue engineering.
Cell lineage, Mesoderm, Regeneration, Reprogramming, Transgenic organisms
Effect of phosphorylation barcodes on arrestin binding to a chemokine receptor
Original Paper | Chemokines | 2025-05-20 20:00 EDT
Qiuyan Chen, Christopher T. Schafer, Somnath Mukherjee, Kai Wang, Martin Gustavsson, James R. Fuller, Katelyn Tepper, Thomas D. Lamme, Yasmin Aydin, Parth Agrawal, Genki Terashi, Xin-Qiu Yao, Daisuke Kihara, Anthony A. Kossiakoff, Tracy M. Handel, John J. G. Tesmer
Unique phosphorylation ‘barcodes’ installed in different regions of an active seven-transmembrane receptor by different G-protein-coupled receptor (GPCR) kinases (GRKs) have been proposed to promote distinct cellular outcomes1, but it is unclear whether or how arrestins differentially engage these barcodes. Here, to address this, we developed an antigen-binding fragment (Fab7) that recognizes both active arrestin2 (β-arrestin1) and arrestin3 (β-arrestin2) without interacting with bound receptor polypeptides. We used Fab7 to determine the structures of both arrestins in complex with atypical chemokine receptor 3 (ACKR3) phosphorylated in different regions of its C-terminal tail by either GRK2 or GRK5 (ref. <a aria-label=”Reference 2” data-test=”citation-ref” data-track=”click” data-track-action=”reference anchor” data-track-label=”link” href=”https://www.nature.com/articles/s41586-025-09024-9#ref-CR2“ id=”ref-link-section-d7947403e621” title=”Schafer, C. T., Chen, Q., Tesmer, J. J. G. & Handel, T. M. Atypical chemokine receptor 3 “senses” CXC chemokine receptor 4 activation through GPCR kinase phosphorylation. Mol. Pharmacol. 104, 174-186 (2023).”>2). The GRK2-phosphorylated ACKR3 resulted in more heterogeneous ‘tail-mode’ assemblies, whereas phosphorylation by GRK5 resulted in more rigid ‘ACKR3-adjacent’ assemblies. Unexpectedly, the finger loops of both arrestins engaged the micelle surface rather than the receptor intracellular pocket, with arrestin3 being more dynamic, partly because of its lack of a membrane-anchoring motif. Thus, both the region of the barcode and the arrestin isoform involved can alter the structure and dynamics of GPCR-arrestin complexes, providing a possible mechanistic basis for unique downstream cellular effects, such as the efficiency of chemokine scavenging and the robustness of arrestin binding in ACKR3.
Chemokines, Cryoelectron microscopy, Kinases
In vivo screen of Plasmodium targets for mosquito-based malaria control
Original Paper | Parasite biology | 2025-05-20 20:00 EDT
Alexandra S. Probst, Douglas G. Paton, Federico Appetecchia, Selina Bopp, Kelsey L. Adams, Tasneem A. Rinvee, Sovitj Pou, Rolf Winter, Esrah W. Du, Sabrina Yahiya, Charles Vidoudez, Naresh Singh, Janneth Rodrigues, Pablo Castañeda-Casado, Chiara Tammaro, Daisy Chen, Karla P. Godinez-Macias, Jasmine L. Jaramillo, Giovanna Poce, Michael J. Rubal, Aaron Nilsen, Elizabeth A. Winzeler, Jake Baum, Jeremy N. Burrows, Michael K. Riscoe, Dyann F. Wirth, Flaminia Catteruccia
The decline in malaria deaths has recently stalled owing to several factors, including the widespread resistance of Anopheles vectors to the insecticides used in long-lasting insecticide-treated nets (LLINs)1,2. One way to mitigate insecticide resistance is to directly kill parasites during their mosquito-stage of development by incorporating antiparasitic compounds into LLINs. This strategy can prevent onward parasite transmission even when insecticides lose efficacy3,4. Here, we performed an in vivo screen of compounds against the mosquito stages of Plasmodium falciparum development. Of the 81 compounds tested, which spanned 28 distinct modes of action, 22 were active against early parasite stages in the mosquito midgut lumen, which in turn prevented establishment of infection. Medicinal chemistry was then used to improve antiparasitic activity of the top hits from the screen. We generated several endochin-like quinolones (ELQs) that inhibited the P. falciparum cytochrome bc1 complex (CytB). Two lead compounds that targeted separate sites in CytB (Qo and Qi) showed potent, long-lasting and stable activity when incorporated and/or extruded into bed net-like polyethylene films. ELQ activity was fully preserved in insecticide-resistant mosquitoes, and parasites resistant to these compounds had impaired development at the mosquito stage. These data demonstrate the promise of incorporating ELQ compounds into LLINs to counteract insecticide resistance and to reduce malaria transmission.
Parasite biology, Phenotypic screening
Unexpected clustering pattern in dwarf galaxies challenges formation models
Original Paper | Cosmology | 2025-05-20 20:00 EDT
Ziwen Zhang, Yangyao Chen, Yu Rong, Huiyuan Wang, Houjun Mo, Xiong Luo, Hao Li
The galaxy correlation function serves as a fundamental tool for studying cosmology, galaxy formation and the nature of dark matter. It is well established that more massive, redder and more compact galaxies tend to have stronger clustering in space1,2. These results can be understood in terms of galaxy formation in cold dark matter (CDM) halos of different mass and assembly history. Here we report an unexpectedly strong large-scale clustering for isolated, diffuse and blue dwarf galaxies, comparable to that seen for massive galaxy groups but much stronger than that expected from their halo mass. Our analysis indicates that the strong clustering aligns with the halo assembly bias seen in simulations3 with the standard ΛCDM cosmology only if more diffuse dwarfs formed in low-mass halos of older ages. This pattern is not reproduced by existing models of galaxy evolution in a ΛCDM framework4,5,6, and our finding provides clues for the search of more viable models. Our results can be explained well by assuming self-interacting dark matter7, suggesting that such a scenario should be considered seriously.
Cosmology, Dark energy and dark matter, Galaxies and clusters, Particle astrophysics
The origin of vertebrate teeth and evolution of sensory exoskeletons
Original Paper | Evolutionary developmental biology | 2025-05-20 20:00 EDT
Yara Haridy, Sam C. P. Norris, Matteo Fabbri, Karma Nanglu, Neelima Sharma, James F. Miller, Mark Rivers, Patrick La Riviere, Phillip Vargas, Javier Ortega-Hernández, Neil H. Shubin
The earliest record of tooth antecedents and the tissue dentine1,2, an early-vertebrate novelty, has been controversially represented by fragmentary Cambrian fossils identified as Anatolepis heintzi3,4,5. Anatolepis exoskeletons have the characteristic tubules of dentine that prompted their interpretation as the first precursors of teeth3, known as odontodes. Debates over whether Anatolepis is a legitimate vertebrate6,7,8 have arisen because of limitations in imaging and the lack of comparative exoskeletal tissues. Here, to resolve this controversy and understand the origin of dental tissues, we synchrotron-scanned diverse extinct and extant vertebrate and invertebrate exoskeletons. We find that the tubules of Anatolepis have been misidentified as dentine tubules and instead represent aglaspidid arthropod sensory sensilla structures9,10. Synchrotron scanning reveals that deep ultrastructural similarities between odontodes and sensory structures also extend to definitive vertebrate tissues. External odontodes of the Ordovician vertebrate Eriptychius11,12,13 feature large dentine tubules1 that are morphologically convergent with invertebrate sensilla. Immunofluorescence analysis shows that the external odontodes of extant chondrichthyans and teleosts retain extensive innervation suggestive of a sensory function akin to teeth14,15,16. These patterns of convergence and innervation reveal that dentine evolved as a sensory tissue in the exoskeleton of early vertebrates, a function retained in modern vertebrate teeth16. Middle-Ordovician fossils now represent the oldest known evidence for vertebrate dental tissues.
Evolutionary developmental biology, Palaeontology
Nature Nanotechnology
Nanoinducer-mediated mitochondria-selective degradation enhances T cell immunotherapy against multiple cancers
Original Paper | Nanoparticles | 2025-05-20 20:00 EDT
Xueting Pan, Zhihang Wang, Mixiao Tan, Ziying Fu, Guangjun Nie, Hai Wang
Cancer immunotherapy utilizing cytotoxic T lymphocytes has demonstrated significant promise in clinical applications, but cancer immunosuppressive mechanisms hamper further progress in T cell immunotherapy. Here we show a correlation between cancer cell mitochondrial content and their resistance to immunotherapy. Observing that cancer cells with higher mitochondrial content show increased resistance to CD8+ T cells, we developed mitochondrial nanoinducers designed to selectively target and degrade mitochondria within autophagosomes. The direct degradation of mitochondria not only enhances the recognition and activation of CD8+ T cells but also increases the susceptibility of cancer cells to CD8+ T cell-mediated cytotoxicity. We demonstrated the feasibility and efficacy of this strategy in multiple in vitro and in vivo tumour therapeutic models. This nanoinducer, designed to manipulate cellular mitochondrial degradation, holds promise as a versatile tool for enhancing adoptive T cell therapy, CAR-T cell therapy and tumour-vaccine-based immunotherapy.
Nanoparticles, Nanostructures
Nature Physics
Quantum neural networks form Gaussian processes
Original Paper | Computational science | 2025-05-20 20:00 EDT
Diego García-Martín, Martín Larocca, M. Cerezo
Classical artificial neural networks initialized from independent and identically distributed priors converge to Gaussian processes in the limit of a large number of neurons per hidden layer. This correspondence plays an important role in the current understanding of the capabilities of neural networks. Here we prove an analogous result for quantum neural networks. We show that the outputs of certain models based on Haar-random unitary or orthogonal quantum neural networks converge to Gaussian processes in the limit of large Hilbert space dimension d. The derivation of this result is more nuanced than in the classical case due to the role played by the input states, the measurement observable and because the entries of unitary matrices are not independent. We show that the efficiency of predicting measurements at the output of a quantum neural network using Gaussian process regression depends on the number of measured qubits. Furthermore, our theorems imply that the concentration of measure phenomenon in Haar-random quantum neural networks is worse than previously thought, because expectation values and gradients concentrate as ${\mathcal{O}}\left({1}/{\operatorname{e}^{d}\sqrt{d}}\right)$.
Computational science, Quantum information, Qubits, Theoretical physics
Valley-controlled photoswitching of metal-insulator nanotextures
Original Paper | Electronic properties and materials | 2025-05-20 20:00 EDT
Hannes Böckmann, Jan Gerrit Horstmann, Felix Kurtz, Manuel Buriks, Karun Gadge, Salvatore R. Manmana, Stefan Wippermann, Claus Ropers
Spatial heterogeneity and phase competition are hallmarks of strongly correlated materials, influencing phenomena such as colossal magnetoresistance and high-temperature superconductivity. Active control over phase textures further promises tunable functionality at the nanoscale. Although light-induced switching of a correlated insulator to a metallic state is well established, optical excitation generally lacks the specificity to select subwavelength domains and determine final textures. Here we drive the domain-specific quench of a textured Peierls insulator using valley-selective photodoping. Polarized excitation exploits the anisotropy of quasi-one-dimensional states at the charge-density-wave gap to initiate an insulator-metal transition with minimal electronic heating. We find that averting dissipation facilitates domain-specific carrier confinement, control over nanotextured phases and reduction in thermal relaxation from the metastable metallic state. This valley-selective photoexcitation approach will enable the activation of electronic phase separation beyond thermodynamic limitations, facilitating optically controlled hidden states, engineered heterostructures and polarization-sensitive percolation networks.
Electronic properties and materials, Nanowires, Phase transitions and critical phenomena, Surfaces, interfaces and thin films
Nature Reviews Materials
Decoding the halogenation cost-performance paradox in organic solar cells
Review Paper | Electronic devices | 2025-05-20 20:00 EDT
Guoping Li, Mohammed Al-Hashimi, Antonio Facchetti, Tobin J. Marks
The power conversion efficiencies of organic solar cells have now surpassed 20%, marking a considerable advance in performance. This progress raises an important question: which molecular or macromolecular modifications contribute most effectively to efficiency gains? Among these, halogenation – specifically fluorination and chlorination – has been a key driver of performance improvements, making it a particularly promising avenue for materials exploration. In this Perspective, we provide a comparative discussion of a broad range of non-halogenated and halogenated building blocks, acceptors and donors, evaluating the impact of halogenation on efficiency and scalability. We also examine critical challenges, including organic solar cell durability, large-scale manufacturability and the realistic costs associated with halogenation, positioning it as a central factor in performance optimization.
Electronic devices, Energy, Solar cells
Physical Review Letters
Quantum Processes as Thermodynamic Resources: The Role of Non-Markovianity
Research article | Open quantum systems | 2025-05-20 06:00 EDT
Guilherme Zambon and Gerardo Adesso
Quantum thermodynamics studies how quantum systems and operations may be exploited as sources of work to perform useful thermodynamic tasks. In real-world conditions, the evolution of open quantum systems typically displays memory effects, resulting in a non-Markovian dynamics. The associated information backflow has been observed to provide advantage in certain thermodynamic tasks. However, a general operational connection between non-Markovianity and thermodynamics in the quantum regime has remained elusive. Here, we analyze the role of non-Markovianity in the central task of extracting work via thermal operations from general multitime quantum processes, as described by process tensors. By defining a hierarchy of four classes of extraction protocols, expressed as quantum combs, we reveal three different physical mechanisms (work investment, multitime correlations, and system-environment correlations) through which non-Markovianity increases the work distillable from the process. The advantages arising from these mechanisms are linked precisely to a quantifier of the non-Markovianity of the process. These results show in very general terms how non-Markovianity of any given quantum process is a fundamental resource that unlocks an enhanced performance in thermodynamics.
Phys. Rev. Lett. 134, 200401 (2025)
Open quantum systems, Quantum correlations in quantum information, Quantum information processing, Quantum thermodynamics, Non-Markovian processes
Linear-Optical Fusion Boosted by High-Dimensional Entanglement
Research article | Optical quantum information processing | 2025-05-20 06:00 EDT
Tomohiro Yamazaki and Koji Azuma
We propose a quantum measurement that probabilistically projects a pair of qudits of dimension $d$ onto a Bell state in a two-qubit subspace. It can be implemented using linear-optical circuits with the success probabilities of $1- {d}^{- 1}$ without ancilla photons and $1- {d}^{- (k+1)}$ with $2({2}^{k}- 1)$ ancilla photons. It allows us to entangle two independently prepared high-dimensional entangled states two dimensionally with higher success probabilities than ones of linear-optical fusion gates on qubits. As an application, we propose a fast quantum repeater protocol with three-qudit GHZ states and quantum memories.
Phys. Rev. Lett. 134, 200801 (2025)
Optical quantum information processing, Quantum communication, protocols & technology, Quantum gates, Quantum measurements, Quantum memories, Quantum optics, Quantum protocols, Quantum repeaters, Qudits, Photons
Properties of Cosmic Lithium Isotopes Measured by the Alpha Magnetic Spectrometer
Research article | Cosmic ray acceleration | 2025-05-20 06:00 EDT
M. Aguilar et al. (AMS Collaboration)
*et al.*A precision measurement of cosmic rays at the International Space Station finds that lithium-7 is produced by the fragmentation of heavier nuclei.
Phys. Rev. Lett. 134, 201001 (2025)
Cosmic ray acceleration, Cosmic ray composition & spectra, Cosmic ray propagation, Cosmic ray sources, Particle astrophysics, Transient & explosive astronomical phenomena
New Constraints on Axionlike Particles with the NEON Detector at a Nuclear Reactor
Research article | Axions | 2025-05-20 06:00 EDT
Byung Ju Park, Jae Jin Choi, Eunju Jeon, Jinyu Kim, Kyungwon Kim, Sung Hyun Kim, Sun Kee Kim, Yeongduk Kim, Young Ju Ko, Byoung-Cheol Koh, Chang Hyon Ha, Seo Hyun Lee, In Soo Lee, Hyunseok Lee, Hyun Su Lee, Jaison Lee, Yoomin Oh, Doojin Kim, Gordan Krnjaic, and Jacopo Nava (NEON Collaboration)
We report new constraints on axionlike particles (ALPs) using data from the NEON experiment, which features 16.7 kg of NaI(Tl) target located 23.7 m from a 2.8 GW thermal power nuclear reactor. Analyzing a total exposure of $3063\text{ }\text{ }\mathrm{kg}\cdot{}\mathrm{day}$, with $1596\text{ }\text{ }\mathrm{kg}\cdot{}\mathrm{day}$ during reactor-on and $1467\text{ }\text{ }\mathrm{kg}\cdot{}\mathrm{day}$ during reactor-off periods, we compared energy spectra to search for ALP-induced signals. No significant signal was observed, enabling us to set exclusion limits at the 95% confidence level. These limits probe previously unexplored regions of the ALP parameter space, particularly for axion masses (${\mathrm{m}}{a}$) near $1\text{ }\text{ }\mathrm{MeV}/{\mathrm{c}}^{2}$. For ALP-photon coupling (${g}{a\gamma }$), limits reach as low as $6.24\times{}{10}^{- 6}\text{ }\text{ }{\mathrm{GeV}}^{- 1}$ at ${\mathrm{m}}{a}=3.0\text{ }\text{ }\mathrm{MeV}/{\mathrm{c}}^{2}$, while for ALP-electron coupling (${g}{ae}$), limits reach $4.95\times{}{10}^{- 8}$ at ${\mathrm{m}}_{a}=1.02\text{ }\text{ }\mathrm{MeV}/{\mathrm{c}}^{2}$. This Letter demonstrates the potential for future reactor experiments to probe unexplored ALP parameter space.
Phys. Rev. Lett. 134, 201002 (2025)
Axions, Nuclear reactors, Particle dark matter
Self-Excited Gravitational Instantons
Alternative gravity theories | 2025-05-20 06:00 EDT
Martin Krššák
We present a novel approach to constructing gravitational instantons based on the observation that the gravitational action of general relativity in its teleparallel formulation can be expressed as a product of the torsion and excitation forms. We introduce a new class of solutions where these two forms are equal, which we term the self-excited instantons, and advocate for their use over the self-dual instantons of Eguchi and Hanson. These new self-excited instantons exhibit striking similarities to BPST instantons in Yang-Mills theory, as their action reduces to a topological Nieh-Yan term, which allows us to identify the axial torsion as a topological current and show that the gravitational action is given by a topological charge.
Phys. Rev. Lett. 134, 201501 (2025)
Alternative gravity theories, General relativity, Instantons, Quantum gravity
Improved Evaluation of the Electroweak Contribution to Muon $g- 2$
Research article | Anomalies | 2025-05-20 06:00 EDT
Martin Hoferichter, Jan Lüdtke, Luca Naterop, Massimiliano Procura, and Peter Stoffer
A precise evaluation of the electroweak contribution to the anomalous magnetic moment of the muon requires control over all aspects of the standard model, ranging from Higgs physics, over multiloop computations for bosonic and (heavy-)fermion diagrams, to nonperturbative effects in the presence of light quarks. Currently, the dominant uncertainties arise from such hadronic effects in the vector–vector–axial-vector three-point function, an improved understanding of which has recently emerged in the context of hadronic light-by-light scattering. Profiting from these developments as well as new perturbative and nonperturbative input for the charm contribution, we obtain ${a}_{\mu }^{\mathrm{EW}}=154.4(4)\times{}{10}^{- 11}$.
Phys. Rev. Lett. 134, 201801 (2025)
Anomalies, Electroweak radiative corrections, Form factors, Strong interaction, Muons, Chiral symmetry, Magnetic moment
Phase-Resolved Attoclock
Research article | Light-matter interaction | 2025-05-20 06:00 EDT
Emmanuel Orunesajo, Sulaiman Abubakar, Blessed Oguh, Yasashri Ranathunga, Jonathan Dubois, Leonardo Rico, Richard Taïeb, Suk Kyoung Lee, and Wen Li
How long an electron spends under the barrier during strong field tunneling ionization is still a controversial issue in attosecond science. We develop a new attoclock technique to address this problem. It exploits the carrier-envelope-phase dependence of angular streaking to extrapolate from elliptically polarized light measurements, for the first time, the deflection angles for circularly polarized light. Thus, we can avoid the ambiguity inherent to the modeling of the conventional elliptical attoclock. Our results show that the deflection angles are solely sensitive to the ionization potentials of targets and tunneling delay is a minor effect.
Phys. Rev. Lett. 134, 203201 (2025)
Light-matter interaction, Multiphoton or tunneling ionization & excitation, Ultrafast optics, Ultrafast phenomena, Attosecond laser spectroscopy
Quantum-State Controlled Formation of Cosmically Relevant Metallic Molecular Ions
Research article | Atom & ion cooling | 2025-05-20 06:00 EDT
G. S. Kocheril, C. Zagorec-Marks, and H. J. Lewandowski
Metal-containing molecular ions are fundamentally important in both terrestrial and interstellar chemistry, yet their formation mechanisms have been largely unexplored experimentally. To address this lack of fundamental understanding of how these ions are created in space, we conducted an experimental study of a quantum-state-controlled reaction between ${\mathrm{Ca}}^{+}$ and ${\mathrm{C}}{2}{\mathrm{H}}{2}$ to investigate a potential unifying mechanism for the formation of metallic molecules. By tuning the quantum-state populations of laser-cooled ${\mathrm{Ca}}^{+}$, we demonstrate precise control over reactivity. Our results reveal a single ionic product, ${\text{CaCCH}}^{+}$, providing valuable insights into the mechanisms underlying the formation of metal-containing ions in space.
Phys. Rev. Lett. 134, 203401 (2025)
Atom & ion cooling, Atom & ion trapping & guiding, Chemical reactions, Molecule trapping & guiding, Ultracold collisions
Conservation of Angular Momentum on a Single-Photon Level
Research article | Angular momentum of light | 2025-05-20 06:00 EDT
L. Kopf, R. Barros, S. Prabhakar, E. Giese, and R. Fickler
Identifying conservation laws is central to every subfield of physics, as they illuminate the underlying symmetries and fundamental principles. A prime example can be found in quantum optics: the conservation of orbital angular momentum (OAM) during spontaneous parametric down-conversion (SPDC) enables the generation of a photon pair with entangled OAM. In this Letter, we report on the observation of OAM conservation in SPDC pumped on the single-photon level by a preceding SPDC process. We implement this cascaded down-conversion scheme in free space, without waveguide confinement, and thereby set the stage for experiments on the direct generation of multiphoton high-dimensional entanglement using all degrees of freedom of light.
Phys. Rev. Lett. 134, 203601 (2025)
Angular momentum of light, Nonlinear optics, Quantum optics, Structured light
Coherent Control of Photon Correlations in Trapped Ion Crystals
Research article | Atom optics | 2025-05-20 06:00 EDT
K. Singh, A. Cidrim, A. Kovalenko, T. M. Pham, O. Číp, L. Slodička, and R. Bachelard
While the spontaneous emission from independent emitters provides spatially uncorrelated photons—a typical manifestation of quantum randomness, the interference of the coherent scattering leads to a well-defined intensity pattern—a feature described by linear optics. We here demonstrate experimentally how the interplay between the two mechanisms in large systems of quantum emitters leads to spatial variations of photon correlations. The implementation with trapped ion crystals in free space allows us to observe the anticorrelation between photon rates and variance of the photon number distributions in chains of up to 18 ions. For smaller crystals of four ions, the transition from antibunching to bunching and super-Poissonian statistics of the scattered light is reported. For higher numbers of scatterers, the photon statistics still display a strong deviation from the fully incoherent scattering case. Our results illustrate how the interference of coherent scattering, combined with spontaneous emission, provides a control mechanism for the light statistics.
Phys. Rev. Lett. 134, 203602 (2025)
Atom optics, Light-matter interaction, Photon statistics, Quantum optics, Quantum states of light, Single photon sources, Spontaneous emission, Ions, Trapped ions
Encoding Arbitrary Ising Hamiltonians on Spatial Photonic Ising Machines
Research article | Optimization problems | 2025-05-20 06:00 EDT
Jason Sakellariou, Alexis Askitopoulos, Georgios Pastras, and Symeon I. Tsintzos
Photonic Ising machines constitute an emergent new paradigm of computation geared toward tackling combinatorial optimization problems that can be reduced to the problem of finding the ground state of an Ising model. Spatial photonic Ising machines (SPIMs) have proven advantageous for simulating fully connected large-scale spin systems. Fine control of a general interaction matrix $J$ has been accomplished so far only through matrix decomposition methods. We introduce and experimentally validate a SPIM instance that enables direct control over the full interaction matrix, allowing the encoding of Ising Hamiltonians with arbitrary couplings and connectivity. We demonstrate the conformity of the experimentally measured Ising energy with the theoretically expected value and then proceed to solve both the unweighted and weighted graph partitioning problems, showcasing a systematic convergence to an optimal solution via simulated annealing. Our approach significantly expands the applicability of SPIMs for real-world applications, as it is more efficient than matrix decomposition methods in the case of sparse problems. It paves the way to encoding the full range of NP problems that are known to be equivalent to Ising models on SPIM devices.
Phys. Rev. Lett. 134, 203801 (2025)
Optimization problems, Photonics, Spin glasses, Holography, Ising model, Optical computing, Simulated annealing
Light-Based Chromatic Aberration Correction of Ultrafast Electron Microscopes
Research article | Electron beams & optics | 2025-05-20 06:00 EDT
Marius Constantin Chirita Mihaila, Neli Laštovičková Streshkova, and Martin Kozák
We propose and theoretically demonstrate a technique that allows one to compensate for chromatic aberrations of traditional electron lenses in ultrafast electron microscopes. The technique is based on space- and time-dependent phase modulation of a pulsed electron beam using interaction with a shaped pulsed ponderomotive lens. The energy-selective focal distance is reached by combining the electron temporal chirp with the time-dependent size of the effective potential, with which the electrons interact. As a result, chromatic aberration can be reduced by up to a factor of 7. This approach paves the way for advanced transverse and longitudinal wave front shaping of electrons in free space.
Phys. Rev. Lett. 134, 203802 (2025)
Electron beams & optics, Quantum optics, Ultrafast optics
Out-of-Equilibrium Fluxes Shape the Self-Organization of Locally Interacting Turbulence
Research article | Two-dimensional turbulence | 2025-05-20 06:00 EDT
Anton Svirsky and Anna Frishman
We study the self-organization of turbulence in a geophysically motivated two-dimensional fluid with local interactions. Using simulations and theory, we show that the out-of-equilibrium flux to small scales imposes a constraint on the large-scale emergent flow. Consequently, a rich phase diagram of large-scale configurations emerges, replacing the unique state found in flows with energy injection below the interaction scale. We explain what sets the boundaries between the different phases and the occurrence of spontaneous symmetry breaking. This letter demonstrates that the selection mechanism of large-scale structures in quasigeostrophic flows can be dramatically altered by forcing above the interaction scale.
Phys. Rev. Lett. 134, 204001 (2025)
Two-dimensional turbulence, Direct numerical simulations, Reynolds-averaged Navier Stokes, Statistical hydrodynamics
Universal Charge Conductance at Abelian–Non-Abelian Quantum Hall Interfaces
Research article | Anyons | 2025-05-20 06:00 EDT
Misha Yutushui, Ady Stern, and David F. Mross
Multiple topologically distinct quantum Hall phases can occur at the same Landau level filling factor. It is a major challenge to distinguish between these phases as they only differ by the neutral modes, which do not affect the charge conductance in conventional geometries. We show that the neutral sector can be determined with coherent charge conductance in a $\pi $-shaped geometry that interfaces three different filling factors. Specifically, non-Abelian paired states at a half-filled Landau level and the anti-Read-Rezayi state can be identified. Interestingly, for interfaces between paired states and Jain states, the electric current in the $\pi $ geometry behaves as if pairs of neutral Majorana edge modes were charge modes of Jain states.
Phys. Rev. Lett. 134, 206301 (2025)
Anyons, Fractional quantum Hall effect, Transport phenomena, Two-dimensional electron gas, Green’s function methods
Advancing Natural Orbital Functional Calculations through Deep Learning-Inspired Techniques for Large-Scale Strongly Correlated Electron Systems
Research article | Electronic structure of atoms & molecules | 2025-05-20 06:00 EDT
Juan Felipe Huan Lew-Yee, Jorge M. del Campo, and Mario Piris
Natural orbital functional (NOF) theory provides a valuable framework for studying strongly correlated systems at an affordable computational cost, with an accuracy comparable to highly demanding wave-function-based methods. However, its widespread adoption in cases involving a large number of correlated electrons has been limited by the extensive iterations required for convergence. In this Letter, we present an approach that integrates the techniques used for optimization in deep learning into NOF calculations, enabling a substantial expansion in the scale of accessible systems. The proposed procedure employs an adaptive momentum-based technique for orbital optimization, alternated with the optimization of occupation numbers, significantly improving the computational feasibility of challenging calculations. We illustrate the capabilities of our approach through three challenging test cases: (i) the symmetric dissociation of a large hydrogen cluster with 1000 electrons, (ii) an analysis of occupancy distributions in fullerenes, and (iii) a study of the singlet-triplet energy gap in linear acenes. These examples demonstrate the method’s applicability to large-scale systems and strongly correlated electron phenomena, extending the reach of NOF theory to increasingly complex systems.
Phys. Rev. Lett. 134, 206401 (2025)
Electronic structure of atoms & molecules, First-principles calculations, Approximation methods for many-body systems, Density matrix methods, Electron-correlation calculations, Quantum chemistry methods
Fractionalized Superconductivity Mediated by Majorana Fermions in the Kitaev-Kondo Lattice
Research article | Majorana fermions | 2025-05-20 06:00 EDT
Matthew Bunney, Urban F. P. Seifert, Stephan Rachel, and Matthias Vojta
Superconductivity usually emerges from a metallic normal state which follows the Fermi-liquid paradigm. If, in contrast, the normal state is a fractionalized non-Fermi liquid, then pairing may either eliminate fractionalization via a Higgs-type mechanism leading to a conventional superconducting state, or pairing can occur in the presence of fractionalization. Here, we discuss a simple model for the latter case: using a combination of perturbation theory and functional renormalization group, we show that the Kitaev-Kondo lattice model displays a fractionalized superconducting phase at weak Kondo coupling. This phase is characterized by Cooper pairing of conventional electronic quasiparticles, coexisting with a spin-liquid background and topological order. Depending on the sign of the Kitaev coupling, we find the pairing to be either of chiral $d$-wave or $p$-wave type for extended doping regions around the van Hove filling. We discuss applications and extensions.
Phys. Rev. Lett. 134, 206602 (2025)
Majorana fermions, Superconductivity, Topological superconductors, Kitaev model, Kondo lattice model
Nonreciprocal Phonons in $\mathcal{P}\mathcal{T}$-Symmetric Antiferromagnets
Research article | Magnetoacoustic effect | 2025-05-20 06:00 EDT
Yafei Ren, Daniyar Saparov, and Qian Niu
Phonon nonreciprocity, indicating different transport properties along opposite directions, has been observed in experiments under a magnetic field. We show that nonreciprocal acoustic phonons can also exist without a magnetic field or net magnetization. We identify crucial contributions in phenomenological elastic theory. In $\mathcal{P}\mathcal{T}$ symmetric antiferromagnets, we find two terms, dubbed flexo viscosity and flexo torque, that induce phonon nonreciprocity. The microscopic origin of these terms is attributed to the derivatives of molecular Berry curvature, manifested as emergent nonlocal magnetic fields on phonons. The symmetry breaking that originated from spin order is transferred to the phonon system through spin-orbit coupling, where the orbital degree of freedom affects the lattice dynamics directly. By electrically breaking inversion symmetry and modifying the spin-orbit coupling, we find extra contributions and show that both the phonon nonreciprocity and helicity can be controlled and enhanced. Importantly, the phonon nonreciprocity is an odd function of the N'eel vector, serving as an indicator of the order parameter.
Phys. Rev. Lett. 134, 206701 (2025)
Magnetoacoustic effect, Mechanical & acoustical properties, Phonons, Topological materials
Picocavity-Enhanced Raman Spectroscopy of Physisorbed ${\mathrm{H}}{2}$ and ${\mathrm{D}}{2}$ Molecules
Research article | Physisorption | 2025-05-20 06:00 EDT
Akitoshi Shiotari, Shuyi Liu, George Trenins, Toshiki Sugimoto, Martin Wolf, Mariana Rossi, and Takashi Kumagai
We report on tip-enhanced Raman spectroscopy of ${\mathrm{H}}{2}$ and ${\mathrm{D}}{2}$ molecules physisorbed within a plasmonic picocavity at 10 K. The intense Raman peaks resulting from the rotational and vibrational transitions are observed at subnanometer gap distances of the junction formed by an Ag tip and an Ag(111) surface, where a picocavity-enhanced field plays a crucial role. A significant redshift of the H-H stretch frequency is observed as the gap distance decreases, while the D-D stretch frequency is unaffected. Density functional theory, path-integral molecular dynamics, and quantum anharmonic vibrational energy calculations suggest that this unexpected isotope effect is explained by a different molecular density between ${\mathrm{H}}{2}$ and ${\mathrm{D}}{2}$ on the surface.
Phys. Rev. Lett. 134, 206901 (2025)
Physisorption, Surface plasmon polariton, Density functional calculations, Scanning tunneling microscopy, Surface-enhanced Raman spectroscopy
Hydrodynamically Consistent Many-Body Harada-Sasa Relation
Research article | Entropy production | 2025-05-20 06:00 EDT
Ramin Golestanian
The effect of hydrodynamic interactions on the nonequilibrium stochastic dynamics of particles—arising from the conservation of momentum in the fluid medium—is examined in the context of the relationship between fluctuations, response functions, and the entropy production rate. The multiplicative nature of the hydrodynamic interactions is shown to introduce subtleties that preclude a straightforward extension of the Harada-Sasa relation. A generalization of the definitions involved in the framework is used to propose a new form of the relation applicable to systems with hydrodynamic interactions. The resulting framework will enable characterization of the nonequilibrium properties of living and active matter systems, which are predominantly in suspensions.
Phys. Rev. Lett. 134, 207101 (2025)
Entropy production, Stochastic thermodynamics, Living matter & active matter, Nonequilibrium systems
Ensemble Inequivalence and Phase Transitions in Unlabeled Networks
Research article | Degree distributions | 2025-05-20 06:00 EDT
Oleg Evnin and Dmitri Krioukov
We discover a first-order phase transition in the canonical ensemble of random unlabeled networks with a prescribed average number of links. The transition is caused by the nonconcavity of microcanonical entropy. Above the critical point coinciding with the graph symmetry phase transition, the canonical and microcanonical ensembles are equivalent and have a well-behaved thermodynamic limit. Below the critical point, the ensemble equivalence is broken, and the canonical ensemble is a mixture of phases: empty networks and networks with average degrees diverging logarithmically with the network size. As a consequence, networks with bounded average degrees do not survive in the thermodynamic limit, decaying into the empty phase. The celebrated percolation transition in labeled networks is thus absent in unlabeled networks. In view of these differences between labeled and unlabeled ensembles, the question of which one should be used as a null model of different real-world networks cannot be ignored.
Phys. Rev. Lett. 134, 207401 (2025)
Degree distributions, Network phase transitions, Network structure, Random graphs
Physical Review X
Locally Purified Density Operators for Symmetry-Protected Topological Phases in Mixed States
Research article | Open quantum systems & decoherence | 2025-05-20 06:00 EDT
Yuchen Guo, Jian-Hao Zhang, Hao-Ran Zhang, Shuo Yang, and Zhen Bi
A new framework reveals symmetry-protected topological phases that exist only in open, noisy quantum systems, offering key insights for identifying and engineering robust quantum states in realistic environments.
Phys. Rev. X 15, 021060 (2025)
Open quantum systems & decoherence, Quantum entanglement, Symmetry protected topological states, Topological phases of matter, Matrix product states, Projected entangled pair states
Polariton Chern Bands in 2D Photonic Crystals beyond Dirac Cones
Research article | Chern insulators | 2025-05-20 06:00 EDT
Xin Xie, Kai Sun, and Hui Deng
Two new types of polariton Chern insulators rely on photonic crystals to achieve topological energy gaps over 10 meV–dramatically larger than previous efforts and well within reach experimentally.
Phys. Rev. X 15, 021061 (2025)
Chern insulators, Exciton polariton, Excitons, Light-matter interaction, Photonic crystals, Photonics, Topological materials
arXiv
Echo State and Band-pass Networks with aqueous memristors: leaky reservoir computing with a leaky substrate
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
T.M. Kamsma, J.J. Teijema, R. van Roij, C. Spitoni
Recurrent Neural Networks (RNN) are extensively employed for processing sequential data such as time series. Reservoir computing (RC) has drawn attention as an RNN framework due to its fixed network that does not require training, making it an attractive for hardware based machine learning. We establish an explicit correspondence between the well-established mathematical RC implementations of Echo State Networks and Band-pass Networks with Leaky Integrator nodes on the one hand and a physical circuit containing iontronic simple volatile memristors on the other. These aqueous iontronic devices employ ion transport through water as signal carriers, and feature a voltage-dependent (memory) conductance. The activation function and the dynamics of the Leaky Integrator nodes naturally materialise as the (dynamic) conductance properties of iontronic memristors, while a simple fixed local current-to-voltage update rule at the memristor terminals facilitates the relevant matrix coupling between nodes. We process various time series, including pressure data from simulated airways during breathing that can be directly fed into the network due to the intrinsic responsiveness of iontronic devices to applied pressures. This is done while using established physical equations of motion of iontronic memristors for the internal dynamics of the circuit.
Soft Condensed Matter (cond-mat.soft)
An adaptive, data-driven multiscale approach for dense granular flows
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
B. Siddani, Weiqun Zhang, Andrew Nonaka, John Bell, Ishan Srivastava
The accuracy of coarse-grained continuum models of dense granular flows is limited by the lack of high-fidelity closure models for granular rheology. One approach to addressing this issue, referred to as the hierarchical multiscale method, is to use a high-fidelity fine-grained model to compute the closure terms needed by the coarse-grained model. The difficulty with this approach is that the overall model can become computationally intractable due to the high computational cost of the high-fidelity model. In this work, we describe a multiscale modeling approach for dense granular flows that utilizes neural networks trained using high-fidelity discrete element method (DEM) simulations to approximate the constitutive granular rheology for a continuum incompressible flow model. Our approach leverages an ensemble of neural networks to estimate predictive uncertainty that allows us to determine whether the rheology at a given point is accurately represented by the neural network model. Additional DEM simulations are only performed when needed, minimizing the number of additional DEM simulations required when updating the rheology. This adaptive coupling significantly reduces the overall computational cost of the approach while controlling the error. In addition, the neural networks are customized to learn regularized rheological behavior to ensure well-posedness of the continuum solution. We first validate the approach using two-dimensional steady-state and decelerating inclined flows. We then demonstrate the efficiency of our approach by modeling three-dimensional sub-aerial granular column collapse for varying initial column aspect ratios, where our multiscale method compares well with the computationally expensive computational fluid dynamics (CFD)-DEM simulation.
Soft Condensed Matter (cond-mat.soft), Computational Physics (physics.comp-ph), Fluid Dynamics (physics.flu-dyn)
40 pages, 10 figures, 2 tables
The evolution of invasion patterns due to surfactant adsorption in anomalous pore distribution: Role of Mass Transfer and Laplace Pressure
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Debanik Bhattacharjee, Guy Z. Ramon, Yaniv Edery
Here, we develop a time-dependent pore network model (PNM) to simulate the effects of surfactant-induced IFT reduction on immiscible displacement driven by constant inlet pressure, with pressure drops across the network calculated using a random resistor network and mass conservation equations. Node-specific flux and velocity are derived using the Hagen-Poiseuille equation, and surfactant adsorption is modeled using the Langmuir isotherm, capturing its impact on fluid-fluid and solid-fluid interfaces within the invaded path. Since the evolution of the invasion pattern comprises the cooperative mechanisms of surfactant mass transfer to the interfaces and the resulting changes in capillary and Laplace pressures, we employ two strategies to quantify this complex feedback behavior: mass transfer-based, introducing a mass transfer timescale, and Laplace pressure-based, scaling with the inlet pressure. Results reveal that an anomalous or heavy-tailed pore throat distribution accelerates the onset of secondary invasions, which enhances the dominance of Laplace pressure. As the distribution becomes less anomalous or more symmetric, mass transfer becomes the dominant mechanism. This interplay highlights the intricate balance between mass transfer and capillary effects in governing the spatio-temporal evolution of immiscible fluid invasion.
Soft Condensed Matter (cond-mat.soft)
Drainage front width in a three-dimensional random porous medium under gravitational and capillary effects
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
A theoretical approach to estimating stable drainage front widths in three-dimensional random porous media under gravitational and capillary effects is presented. Based on the frontier of the infinite cluster in gradient percolation, we propose an expression for the 3D front width dependent on the pore-network topology, the distribution of capillary pressure thresholds for the pore throats, the stabilizing capillary pressure gradient, the average pore size, and the correlation length critical exponent from percolation in three dimensions. Theoretical predictions are successfully compared to numerical results obtained with a bond invasion-percolation model for a wide range of drainage flow parameters.
Soft Condensed Matter (cond-mat.soft)
32 pages, 11 figures
Long-term microgravity experiments reveal a new mechanism for particle aggregation in suspension
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Fabian Kleischmann, Bernhard Vowinckel, Eckart Meiburg, Paolo Luzzatto-Fegiz
Microgravity experiments on board the International Space Station, combined with particle-resolved direct numerical simulations, were conducted to investigate the long-term flocculation behavior of clay suspensions in saline water in the absence of gravity. After an initial homogenization of the suspensions, different clay compositions were continuously monitored for 99 days, allowing a detailed analysis of aggregate growth through image processing. The results indicate that the onboard oscillations (g-jitter) may have accelerated the aggregation process. Aggregate growth driven by these oscillations is found to occur at a faster rate than aggregation caused by Brownian motion. This effect is further confirmed by numerical simulations, which also demonstrated that parameters such as the oscillation amplitude and the solid volume fraction influence growth acceleration. These findings highlight that oscillations may act as a previously unrecognized mechanism that contributes to particle aggregation in fluids.
Soft Condensed Matter (cond-mat.soft)
13 pages, 10 figures, 3 tables, supplementary information provided as ancillary file
Genetic Algorithm-Accelerated Computational Discovery of Liquid Crystal Polymers with Enhanced Optical Properties
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Jianing Zhou, Yuge Huang, Arman Boromand, Keian Noori, Lafe Purvis, Chulwoo Oh, Lu Lu, Zachary W. Ulissi, Vahe Gharakhanyan, Xinyue Zhang
Liquid crystal polymers with exceptional optical properties are highly promising for next-generation virtual, augmented, and mixed reality (VR/AR/MR) technologies, serving as high-performance, compact, lightweight, and cost-effective optical components. However, the growing demands for optical transparency and high refractive index in advanced optical devices present a challenge for material discovery. In this study, we develop a novel approach that integrates first-principles calculations with genetic algorithms to accelerate the discovery of liquid crystal polymers with low visible absorption and high refractive index. By iterating within a predefined space of molecular building blocks, our approach rapidly identifies reactive mesogens that meet target specifications. Additionally, it provides valuable insights into the relationships between molecular structure and properties. This strategy not only accelerates material screening but also uncovers key molecular design principles, offering a systematic and scalable alternative to traditional trial-and-error methods.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
Evaluation of the Influence of Structural Parameters on the Mechanical Properties of Foam Glasses via In-Situ Micro-CT Mechanical Testing
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Mateus Gruener Lima, Tobias Günther, Thu Trang Võ, Eduardo Inocente Jussiani, Dirk Enke, Urs A. Peuker, Ralf B. Wehrspohn, Juliana Martins de Souza e Silva
Foam glass made from waste glass has high chemical and mechanical stability and flexible structural properties, making it suitable for a wide range of applications. To ensure its reliability, it is essential to understand its mechanical properties and fracture mechanisms. In this study, we investigated morphological features related to pore structure alongside mechanical properties, specifically Young’s modulus and compressive strength, of three different monolithic foam glass samples using micro-computed tomography combined with ex-situ and in-situ uniaxial compression experiments and Digital Volume Correlation (DVC) analysis. The foam glasses exhibit an inverse relationship between mechanical strength and factors such as wall thickness, porosity, pore size and irregularity, with the compressive strength following a power-law correlation with the proportion of large pores. The multi-peak behavior of the stress-strain curves indicates micro-cracking within the porous lattice. Micro-CT data show that damage is concentrated at the upper and lower extremes of the specimens, and that the applied strain induces changes in the porosity, mean pore diameter, and pore sphericity, driven by deformation and collapse of the pore structures. DVC analysis quantitatively validated these observations.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
19 pages, 9 figures
Impact of Acid Hydrolysis on Morphology, Rheology, Mechanical Properties, and Processing of Thermoplastic Starch
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Saffana Kouka, Veronika Gajdosova, Beata Strachota, Ivana Sloufova, Radomir Kuzel, Zdenek Stary, Miroslav Slouf
We modified native wheat starch using 15, 30, and 60 min of acid hydrolysis (AH). The non-modified and AH-modified starches were converted to highly-homogeneous thermo-plastic starches (TPS) using our two-step preparation protocol consisting of solution cast-ing and melt-mixing. Our main objective was to verify if the AH can decrease the pro-cessing temperature of TPS. All samples were characterized in detail by microscopic, spectroscopic, diffraction, thermomechanical, rheological, and micromechanical methods, including in situ measurements of torque and temperature during the final melt-mixing step. The experimental results showed that: (i) the AH decreased the average molecular weight preferentially in the amorphous regions, (ii) the lower-viscosity matrix in the AH-treated starches resulted in slightly higher crystallinity, and (iii) all AH-modified TPS with less viscous amorphous phase and higher content of crystalline phase exhibited similar properties. The effect of the higher crystallinity predominated at laboratory tem-perature and low deformations, resulting in slightly stiffer material. The effect of the low-er-viscosity dominated during the melt mixing, where the shorter molecules acted as a lubricant and decreased the in situ measured processing temperature. The AH-induced decrease in the processing temperature could be beneficial for energy savings and/or pos-sible temperature-sensitive admixtures to TPS systems.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
Accepted version
Polymer Data Challenges in the AI Era: Bridging Gaps for Next-Generation Energy Materials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Ying Zhao, Guanhua Chen, Jie Liu
The pursuit of advanced polymers for energy technologies, spanning photovoltaics, solid-state batteries, and hydrogen storage, is hindered by fragmented data ecosystems that fail to capture the hierarchical complexity of these materials. Polymer science lacks interoperable databases, forcing reliance on disconnected literature and legacy records riddled with unstructured formats and irreproducible testing protocols. This fragmentation stifles machine learning (ML) applications and delays the discovery of materials critical for global decarbonization. Three systemic barriers compound the challenge. First, academic-industrial data silos restrict access to proprietary industrial datasets, while academic publications often omit critical synthesis details. Second, inconsistent testing methods undermine cross-study comparability. Third, incomplete metadata in existing databases limits their utility for training reliable ML models. Emerging solutions address these gaps through technological and collaborative innovation. Natural language processing (NLP) tools extract structured polymer data from decades of literature, while high-throughput robotic platforms generate self-consistent datasets via autonomous experimentation. Central to these advances is the adoption of FAIR (Findable, Accessible, Interoperable, Reusable) principles, adapted to polymer-specific ontologies, ensuring machine-readability and reproducibility. Future breakthroughs hinge on cultural shifts toward open science, accelerated by decentralized data markets and autonomous laboratories that merge robotic experimentation with real-time ML validation. By addressing data fragmentation through technological innovation, collaborative governance, and ethical stewardship, the polymer community can transform bottlenecks into accelerants.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
45 pages, 0 figures
Simulating non-Brownian suspensions with non-homogeneous Navier slip boundary conditions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Daniela Moreno-Chaparro, Florencio Balboa Usabiaga, Nicolas Moreno, Marco Ellero
Fluid-structure interactions are commonly modeled using no-slip boundary conditions. However, small deviations from these conditions can significantly alter the dynamics of suspensions and particles, especially at the micro and nano scales. This work presents a robust implicit numerical method for simulating non-colloidal suspensions with non-homogeneous Navier slip boundary conditions. Our approach is based on a regularized boundary integral formulation, enabling accurate and efficient computation of hydrodynamic interactions. This makes the method well-suited for large-scale simulations. We validate the method by comparing computed drag forces on homogeneous and Janus particles with analytical results. Additionally, we consider the effective viscosity of suspensions with varying slip lengths, benchmarking against available analytical no-slip and partial-slip theories.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
16 pages, 7 figures
Autonomous nanoparticle synthesis by design
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Andy S. Anker, Jonas H. Jensen, Miguel Gonzalez-Duque, Rodrigo Moreno, Aleksandra Smolska, Mikkel Juelsholt, Vincent Hardion, Mads R. V. Jorgensen, Andres Faina, Jonathan Quinson, Kasper Stoy, Tejs Vegge
Controlled synthesis of materials with specified atomic structures underpins technological advances yet remains reliant on iterative, trial-and-error approaches. Nanoparticles (NPs), whose atomic arrangement dictates their emergent properties, are particularly challenging to synthesise due to numerous tunable parameters. Here, we introduce an autonomous approach explicitly targeting synthesis of atomic-scale structures. Our method autonomously designs synthesis protocols by matching real time experimental total scattering (TS) and pair distribution function (PDF) data to simulated target patterns, without requiring prior synthesis knowledge. We demonstrate this capability at a synchrotron, successfully synthesising two structurally distinct gold NPs: 5 nm decahedral and 10 nm face-centred cubic structures. Ultimately, specifying a simulated target scattering pattern, thus representing a bespoke atomic structure, and obtaining both the synthesised material and its reproducible synthesis protocol on demand may revolutionise materials design. Thus, ScatterLab provides a generalisable blueprint for autonomous, atomic structure-targeted synthesis across diverse systems and applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Machine Learning (cs.LG)
Interplay of magnetic textures with spin-orbit coupled substrates
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Zachary Llewellyn, Eric Mascot, Oleg A. Tretiakov, Stephan Rachel
Magnetic textures such as skyrmions in thin films grown on substrates possess significant technological potential. Inhomogeneous magnetic structures can be described as homogeneous ferromagnetic order in the presence of anisotropic spin-orbit coupling (SOC). It remains unexplored, however, how this {\it induced} SOC stemming from the magnetic textures interacts with the SOC of the substrate. Here we show that these two contributions to SOC are in general {\it not} additive. We demonstrate this by employing a spintronics gauge theory. We further compute local currents which, when considered in the proper frame, match the spintronics gauge theory results. Finally, we analyze global transport quantities and show that they substantiate our previous results quantitatively. The implications for skyrmionics as well as topological superconductivity are discussed.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 6 figures
String-Membrane-Nets from Higher-Form Gauging: An Alternate Route to $p$-String Condensation
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-21 20:00 EDT
Pranay Gorantla, Abhinav Prem, Nathanan Tantivasadakarn, Dominic J. Williamson
We present a new perspective on the $ p$ -string condensation procedure for constructing 3+1D fracton phases by implementing this process via the gauging of higher-form symmetries. Specifically, we show that gauging a 1-form symmetry in 3+1D that is generated by Abelian anyons in isotropic stacks of 2+1D topological orders naturally results in a 3+1D $ p$ -string condensed phase, providing a controlled non-perturbative construction that realizes fracton orders. This approach clarifies the symmetry principles underlying $ p$ -string condensation and generalizes the familiar connection between anyon condensation and one-form gauging in two spatial dimensions. We demonstrate this correspondence explicitly in both field theories and lattice models: in field theory, we derive the foliated field theory description of the $ \mathbb{Z}_N$ X-Cube model by gauging a higher-form symmetry in stacks of 2+1D $ \mathbb{Z}_N$ gauge theories; on the lattice, we show how gauging a diagonal 1-form symmetry in isotropic stacks of $ G$ -graded string-net models leads to string-membrane-nets hosting restricted mobility excitations. This perspective naturally generalizes to spatial dimensions $ d \geq 2$ and provides a step towards building an algebraic theory of $ p$ -string condensation.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th), Quantum Physics (quant-ph)
19 pages, 3 figures
Quasiparticles and optical conductivity in the mixed state of Weyl superconductors with unconventional pairing
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-21 20:00 EDT
Previous investigations have revealed that the Weyl superconductor (WeylSC) and the two-dimensional (2D) nodal superconductor, realized through a topological insulator-superconductor heterostructure, can exhibit a Dirac-like Landau level (LL) structure that scales with $ \sqrt{n}$ in the presence of a vortex lattice, where $ n$ is the index of the LLs. Here, we investigate the excitation spectrum in the mixed state of WeylSCs with unconventional pairing and find that, unlike in the spin-singlet case, QP bands for the spin-triplet pairing show surprising dispersion, except for the chiral symmetry-protected, dispersionless zeroth Landau level (ZLL). Different pairing symmetries in WeylSCs also result in distinct magneto-optical responses, manifested as characterized magneto-optical conductivity curves. We also reveal that, compared to the topologically protected, charge-neutral, localized Majorana zero mode (MZM), the chiral symmetry-protected ZLL is non-charge-neutral and delocalized. Both of these zero modes may be observed in the vortex of a superconductor heterostructure.
Superconductivity (cond-mat.supr-con)
9pages, 7figures
Bootstrapping Nonequilibrium Stochastic Processes
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-21 20:00 EDT
We show that bootstrap methods based on the positivity of probability measures provide a systematic framework for studying both synchronous and asynchronous nonequilibrium stochastic processes on infinite lattices. First, we formulate linear programming problems that use positivity and invariance property of invariant measures to derive rigorous bounds on their expectation values. Second, for time evolution in asynchronous processes, we exploit the master equation along with positivity and initial conditions to construct linear and semidefinite programming problems that yield bounds on expectation values at both short and late times. We illustrate both approaches using two canonical examples: the contact process in 1+1 and 2+1 dimensions, and the Domany-Kinzel model in both synchronous and asynchronous forms in 1+1 dimensions. Our bounds on invariant measures yield rigorous lower bounds on critical rates, while those on time evolutions provide two-sided bounds on the half-life of the infection density and the temporal correlation length in the subcritical phase.
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th), Optimization and Control (math.OC), Probability (math.PR)
54 pages, 13 figures, 4 tables
Classical Criticality via Quantum Annealing
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-21 20:00 EDT
Pratik Sathe, Andrew D. King, Susan M. Mniszewski, Carleton Coffrin, Cristiano Nisoli, Francesco Caravelli
Quantum annealing provides a powerful platform for simulating magnetic materials and realizing statistical physics models, presenting a compelling alternative to classical Monte Carlo methods. We demonstrate that quantum annealers can accurately reproduce phase diagrams and simulate critical phenomena without suffering from the critical slowing down that often affects classical algorithms. To illustrate this, we study the piled-up dominoes model, which interpolates between the ferromagnetic 2D Ising model and Villain’s fully frustrated ``odd model’’. We map out its phase diagram and for the first time, employ finite-size scaling and Binder cumulants on a quantum annealer to study critical exponents for thermal phase transitions. Our method achieves systematic temperature control by tuning the energy scale of the Hamiltonian, eliminating the need to adjust the physical temperature of the quantum hardware. This work demonstrates how, through fine-tuning and calibration, a quantum annealer can be employed to apply sophisticated finite-size scaling techniques from statistical mechanics. Our results establish quantum annealers as robust statistical physics simulators, offering a novel pathway for studying phase transitions and critical behavior.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
Single-photon detection enabled by negative differential conductivity in moiré superlattices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Krystian Nowakowski, Hitesh Agarwal, Sergey Slizovskiy, Robin Smeyers, Xueqiao Wang, Zhiren Zheng, Julien Barrier, David Barcons Ruiz, Geng Li, Riccardo Bertini, Matteo Ceccanti, Iacopo Torre, Bert Jorissen, Antoine Reserbat-Plantey, Kenji Watanabe, Takashi Taniguchi, Lucian Covaci, Milorad V. Milošević, Vladimir Fal’ko, Pablo Jarillo-Herrero, Roshan Krishna Kumar, Frank H. L. Koppens
Detecting individual light quanta is essential for quantum information, space exploration, advanced machine vision, and fundamental science. Here, we introduce a novel single photon detection mechanism using highly photosensitive non-equilibrium electron phases in moiré materials. Using tunable bands in bilayer graphene/hexagonal-boron nitride superlattices, we engineer negative differential conductance and a sensitive bistable state capable of detecting single photons. Operating in this regime, we demonstrate single-photon counting at mid-infrared (11.3 microns) and visible wavelengths (675 nanometres) and temperatures up to 25 K. This detector offers new prospects for broadband, high-temperature quantum technologies with CMOS compatibility and seamless integration into photonic integrated circuits (PICs). Our analysis suggests the mechanism underlying our device operation originates from negative differential velocity, and represents an important milestone in the field of high-bias transport in two-dimensional moiré quantum materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph), Optics (physics.optics)
Boundary-condition-assisted chiral-symmetry protection of the zeroth Landau level on a two-dimensional lattice
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
A. Donís Vela, C.W.J. Beenakker
The massless two-dimensional Dirac equation in a perpendicular magnetic field B supports a B-independent “zeroth Landau level”, a dispersionless zero-energy-mode protected by chiral symmetry. On a lattice the zero-mode becomes doubly degenerate with states of opposite chirality, which removes the protection and allows for a broadening when the magnetic field is non-uniform. It is known that this fundamental obstruction can be avoided by spatially separating the doubly degenerate states, adjoining +B and -B regions in a system of twice the size. Here we show that the same objective can be achieved without doubling the system size. The key ingredients are 1) a chirality-preserving “tangent fermion” discretization of the Dirac equation; and 2) a boundary condition that ensures the zero-mode contains only states of a single chirality.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages, 7 figures
Symmetry-Driven Trimer Formation in Kagome Correlated Electron Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Varsha Kumari, Julia Bauer, Alexandru B. Georgescu
Correlated electron materials with molecular orbital states extending over transition metal clusters can host multiferroicity, spin frustration, and unconventional insulating phases. However, the fundamental criteria that govern cluster formation and stability remain unclear. Here, we identify a symmetry, correlation, and electron filling driven criteria that stabilize triangular metal trimers in materials displaying transition metal kagome patterns. Using density functional theory and chemical bonding analysis, we show that trimer formation emerges when 6 to 8 electrons occupy molecular orbitals derived from transition metal d-states, achieving near complete filling of bonding states while avoiding antibonding occupation, and correlations are of intermediate strength. This principle explains the stability of Nb$ _3$ X$ _8$ (X = Cl, Br, I), and more broadly, our findings offer a general design rule to obtain quantum materials with quantum states extended across transition metal clusters.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Combined tight-binding and configuration interaction study of unfolded electronic structure of G-color center in Si
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Jakub Valdhans, Petr Klenovský
We have theoretically studied the G-center in bulk silicon material using the empirical tight-binding model for calculations of unfolded band structures with configuration interaction correction for the exciton at $ \Gamma$ point of the Brillouin zone. The G-center in B configuration (emissive) being a candidate structure as the telecom single- and entangled-photon source has two substitutional carbons and one interstitial atom embedded into the bulk in six equally possible configurations. Taking the advantage of the low computation effort of the tight-binding and unfolding approach, it is possible to calculate and analyze the behavior of a variety of the electronic configurations. Our tight-binding model is able to describe not only the behavior of the G-center in the silicon bulk but using the unfolding approach it can also pinpoint the contributions of different elements of the supercell on the final pseudo-band structure. Moreover, the configuration interaction correction with single-particle basis states computed by our unfolded tight-binding model predicts a very small fine-structure splitting of the ground state exciton both for bright and dark doublet in the studied system. That underscores the possibility of the silicon G-center to become a very good emitter of single and entangled photons for quantum communication and computation applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Temperature dependence of coercivity for isolated Ni nanowires unraveled by high-sensitivity micromagnetometry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Evelyn A. Escudero Bruna, Federico Romá, Fernando Meneses, Paula. G. Bercoff, Moira I. Dolz
Magnetic nanowires are critical components in fields such as data storage and spintronics, where precise control of their magnetic properties is essential for device optimization. In particular, the behavior of isolated nanowires is often different from that of an ensemble, offering an opportunity to explore the role that dipolar and magnetoelastic interactions play in the latter system. Unfortunately, the comparison between a collection of nanowires and single ones is often poorly characterized, as measuring individual nanowires with weak magnetic signals is a challenging task. In this work, we employ a highly-sensitive micromechanical torsional oscillator to measure the magnetic response of few individual Ni nanowires with 72 +/- 5 nm average diameter, fabricated by electrodeposition in anodic aluminum oxide templates as an array and subsequently released from this membrane. When comparing the magnetic properties as a function of temperature between single nanowires and the array, we show that coercivity values of individual nanowires are at least twice as large as for the array in the range 5 K - 200 K. Also, we characterize the differences in the hysteresis loops, which are more squared for isolated nanowires, with a high magnetic remanence close to 80 % of the saturation value. Our results highlight the crucial role of dipolar and mechanical interactions in modifying the magnetic behavior of nanowires arrays, providing valuable insights for the design and application of nanowires-based magnetic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
7 pages, 7 figures
Solving Lyapunov equations for electrically driven ternary electrolytes – application to long-range van der Waals interactions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Guangle Du, Bing Miao, David S. Dean
Stochastic density functional theory (SDFT) has been widely used to study the out of equilibrium properties of electrolyte solutions. Examples include investigations of electrical conductivity – both within and beyond linear response – and modifications of thermal van der Waals interactions in driven electrolytes. Within the approximation scheme derived from linearizing SDFT for fluctuations around mean densities, the steady state correlation functions between the $ N$ ionic species are governed by linear Lyapunov equations of degree $ N(N+1)/2$ . Consequently, the system’s complexity increases significantly when transitioning from binary to ternary electrolytes, and few analytical results exist for the latter. In this paper, we demonstrate how – for the specific case of electrolytes – the Lyapunov equations can be reduced to a system of $ N$ linear equations. We apply this reduction to compute the long-range component of the van der Waals interaction between two slabs containing a ternary electrolyte under an applied electric field parallel to the slabs. Unlike the binary electrolyte case, we show that the resulting van der Waals interaction for a ternary electrolyte depends on the ionic species’ diffusion coefficients, highlighting its inherently out of equilibrium nature.
Soft Condensed Matter (cond-mat.soft)
24 pages, 5 figures
Early Stages of Self-Healing at Tungsten Grain Boundaries from Ab Initio Machine Learning Simulations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Jorge Suárez-Recio, Pablo M. Piaggi, Francisco J. Domínguez-Gutiérrez, Raquel Gonzalez-Arrabal, Roberto Iglesias
Nanostructured tungsten has been reported as a possible alternative plasma-facing material due to its potential ability to self-heal radiation-induced defects, a property that is attributed to its high density of grain boundaries (GB). Here, we study the initial stages of self-healing at tungsten interfaces with molecular dynamics simulations driven by a machine-learning interatomic potential tailored to one of the most common GBs found in experiments. Our model accurately reproduces the ab initio potential energy surface derived from density functional theory (DFT) calculations and outperforms previously reported empirical interatomic potentials in predicting defect energetics. The simulations reveal low-temperature defect migration to GBs driven by rapid dumbbell-like ordering and subsequent accommodation along GB grooves. In contrast to empirical potentials, which predict unexpected GB degradation at high temperatures after defect migration, our model maintains stable GB motifs over the investigated temperature range. The temperature-dependent defect counts, evaluated using an Arrhenius-like fit, yield an average interstitial migration energy of 0.048 eV, in agreement with experiment.
This work underscores the capabilities of ab initio machine learning simulations in accurately modeling defect-GB interactions and highlights their potential to contribute to the development of radiation tolerant materials.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Probing and Tuning Strain-localized Exciton Emission in 2D Material Bubbles at Room Temperature
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Junze Zhou, John Thomas, Thomas P. Darlington, Edward S. Barnard, Atsushi Taguchi, Adam Schwartzberg, Alexander Weber-Bargioni
Excitons in 2D material bubbles-nanoscale deformations in atomically thin materials, typically exhibiting a dome-like shape-are confined by the strain effect, exhibiting extraordinary emission properties, such as single photon generation, enhanced light emission, and spectrally tunable excitonic states. While the strain profiles of these bubbles have been extensively studied, this work provides an approach (1) to directly visualize the associated exciton properties, revealing an intrinsic emission wavelength shift of approximately 40 nm, and (2) actively modify local strain, enabling further exciton emission tuning over a range of 50 nm. These are achieved by emission mapping and nanoindentation using a dielectric near-field probe, which enables the detection of local emission spectra and emission lifetimes within individual bubbles. Statistical analysis of 67 bubbles uncovers an emission wavelength distribution centered around 780 nm. Furthermore, saturation behavior in the power-dependent studies and the associated lifetime change reveal the localized nature of the strain-induced states. These findings provide direct insights into the strain-localized emission dynamics in bubbles and establish a robust framework for non-destructive, reversible, and predictable nanoscale emission control, presenting a potential avenue for developing next-generation tunable quantum optical sources.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Active-Spin-State-Derived Descriptor for Hydrogen Evolution Reaction Catalysis
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Yu Tan, Lei Li, Zi-Xuan Yang, Tao Huang, Qiao-Ling Wang, Tao Zhang, Jing-Chun Luo, Gui-Fang Huang, Wangyu Hu, Wei-Qing Huang
Spin states are pivotal in modulating the electrocatalytic activity of transition-metal (TM)-based compounds, yet quantitatively evaluating the activity-spin state correlation remains a formidable challenge. Here, we propose an ‘activity index n’ as a descriptor, to assess the activity of the spin states for the hydrogen evolution reaction (HER). n descriptor integrates three key electronic parameters: the proportion (P), broadening range (R) and center cc of active spin state, which collectively account for the electronic structure modulation induced by both the intrinsic active site and its local coordination environment. Using 1T-phase ZrSe2-anchored TM atoms (TM=Sc to Ni) as prototypes, we reveal that the correlation between Gibbs free energy and the n value follows a linear relation, namely, the vGH reduces as the n decreases. Notably, ZrSe2-Mn exhibits the optimal n value (-0.56), corresponding the best HER activity with a vGH of 0.04 eV closer to the thermoneutral ideal value (0 eV) than even Pt (vGH = -0.09 eV). This relationship suggests that n is the effective descriptor of active spin state for HER of TM-based catalysts. Our study brings fundamental insights into the HER activity-spin state correlation, offering new strategies for HER catalyst design.
Materials Science (cond-mat.mtrl-sci)
17 pages, 5 figures
Substrate Effect on Electronic Band Structure and Topological Property in Monolayer V2O3 Magnetic Topological Insulator
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Zheng Wang, Kaixuan Chen, Shu-Shen Lyu
Monolayer V2O3, a two-dimensional magnetic topological insulator with intrinsic ferromagnetic order and a nontrivial band gap, offers a promising platform for realizing quantum anomalous Hall (QAH) states. Using first-principles density functional theory calculations, we systematically investigate the impact of substrate selection on its electronic and topological properties. By modeling heterostructures with van der Waals (vdW) substrates, we demonstrate that non-magnetic substrates such as h-BN preserve the QAH phase with a Chern number C = 1, maintaining gapless chiral edge states. In contrast, ferromagnetic substrates induce extra electrons, destroying the topological order by shifting the Fermi level. These findings establish substrate engineering as a pivotal strategy for experimental realization of dissipationless edge transport in V2O3-based vdW heterostructures, advancing their potential applications as low-power topological electronics.
Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
Lorentz force on superconducting vortices near line defects
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-21 20:00 EDT
In type-II superconductors, magnetic flux penetrates in the form of quantized vortices whose dissipative motion, driven by the Lorentz force, can degrade superconductivity. Understanding vortex dynamics in both homogeneous regions and near unavoidable structural defects is crucial for superconducting applications. This study examines a scenario in which a superconducting quantum interference device (SQUID) scans across a thin-film superconductor containing line defects. We first estimate the radial Lorentz force on a vortex in a homogeneous region using both analytical methods and numerical simulations based on the fast Fourier transform algorithm. For a film with a Pearl length of 400 micrometers and a SQUID height of 4 micrometers, we find that the SQUID tip can exert a force of approximately 3 femtonewtons on a vortex. We then evaluate the Lorentz force on vortices near two parallel line defects. Our results show that the Lorentz force is enhanced for vortices pinned on or between line defects. Vortices pinned on the line defects experience force enhancement predominantly perpendicular to the defects, while vortices in between experience enhancement along the defect direction. These findings enable more accurate estimation of Lorentz forces on vortices near line defects in thin-film superconductors and contribute to the broader understanding of vortex pinning and dynamics in defect-engineered superconductors. The methods can be extended to bulk superconductors and generalized to other defect geometries.
Superconductivity (cond-mat.supr-con)
Experimental and theoretical studies of WO3-Vulcan XC-72 electrocatalyst enhanced H2O2 yield ORR performed in acid and alkaline medium
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
João Paulo C Moura, Lanna EB Lucchetti, Caio M Fernandes, Aline B Trench, Camila N Lange, Bruno L Batista, James M Almeida, Mauro C Santos
The oxygen reduction reaction (ORR) plays a pivotal role in clean energy generation and sustainable chemical production, particularly in the synthesis of hydrogen peroxide (H\textsubscript{2}O\textsubscript{2}). In this study, WO\textsubscript{3}/Vulcan-XC72 electrocatalysts were synthesized and characterized for ORR applications, evaluating the WO\textsubscript{3} to Vulcan-XC72 ratio and examining electrolyte pH effects across acidic and alkaline media. Structural characterization confirmed successful synthesis of monoclinic WO\textsubscript{3} with nanoflower morphology, which enhanced surface hydrophilicity and oxygen functional groups. Electrochemical tests demonstrated WO\textsubscript{3}/C’s superior H\textsubscript{2}O\textsubscript{2} selectivity compared to pure Vulcan-XC72 in both media, revealing a pH-dependent ORR mechanism. Using WO\textsubscript{3}/C gas diffusion electrodes (GDEs), we achieved 862,mg,L\textsuperscript{-1} H\textsubscript{2}O\textsubscript{2} accumulation after 120,min at 100,mA,cm\textsuperscript{-2}. The enhanced performance stems from increased oxygen functional groups, improved hydrophilicity, and WO\textsubscript{3} nanoflower synergistic effects, as supported by theoretical calculations, establishing WO\textsubscript{3}/Vulcan as a promising catalyst for electrochemical H\textsubscript{2}O\textsubscript{2} production.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Deeply Nonlinear Magnonic Directional Coupler
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Xu Ge, Roman Verba, Philipp Pirro, Andrii V. Chumak, Qi Wang
Dipolar coupling between closely spaced magnetic waveguides enables the design of magnonic directional couplers - universal devices capable of functioning as signal combiners, power splitters, demultiplexers, and more. The wavelength-dependent coupling, combined with the weak nonlinear variation of a spin wave’s wavelength at constant-frequency, introduces power-dependent characteristics of directional couplers. This property has been leveraged in the development of magnonic logic elements and other applications. Here, we explore another nonlinear phenomenon in a directional coupler arising purely from the nonlinear frequency shift of spin waves. We show that a strong nonlinear frequency shift causes the coupler to behave as if composed of nonidentical waveguides, suppressing the energy transfer between the waveguides. The transition from complete to negligible energy transfer exhibits a sharp threshold behavior, where the critical power is determined by the coupling strength and nonlinear frequency shift parameter. Based on these findings, a switchable directional coupler as a critical component for future integrated magnonic circuits is designed and validated by micromagnetic simulations.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages, 4 figures
Physics-Guided Sequence Modeling for Fast Simulation and Design Exploration of 2D Memristive Devices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Benjamin Spetzler, Elizaveta Spetzler, Saba Zamankhani, Dilara Abdel, Patricio Farrell, Kai-Uwe Sattler, Martin Ziegler
Modeling hysteretic switching dynamics in memristive devices is computationally demanding due to coupled ionic and electronic transport processes. This challenge is particularly relevant for emerging two-dimensional (2D) devices, which feature high-dimensional design spaces that remain largely unexplored. We introduce a physics-guided modeling framework that integrates high-fidelity finite-volume (FV) charge transport simulations with a long short-term memory (LSTM) artificial neural network (ANN) to predict dynamic current-voltage behavior. Trained on physically grounded simulation data, the ANN surrogate achieves more than four orders of magnitude speedup compared to the FV model, while maintaining direct access to physically meaningful input parameters and high accuracy with typical normalized errors <1%. This enables iterative tasks that were previously computationally prohibitive, including inverse modeling from experimental data, design space exploration via metric mapping and sensitivity analysis, as well as constrained multi-objective design optimization. Importantly, the framework preserves physical interpretability via access to detailed spatial dynamics, including carrier densities, vacancy distributions, and electrostatic potentials, through a direct link to the underlying FV model. Our approach establishes a scalable framework for efficient exploration, interpretation, and model-driven design of emerging 2D memristive and neuromorphic devices.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Computational Physics (physics.comp-ph)
Significant Enhancement of Carrier Mobility in Finite vs. Infinite Square Quantum Wells: A Comparative Study of GaAs/In$x$Ga${1-x}$As/GaAs Heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Truong Van Tuan, Nguyen Dung Chinh, Tran Trong Tai, Vo Van Tai, Nguyen Duy Vy
The geometry of quantum wells (QWs) critically influences carrier mobility, yet systematic comparisons between finite and infinite square QWs remain scarce. We present a comprehensive study of GaAs/In$ x$ Ga$ {1-x}$ As/GaAs heterostructures using a variational-subband-wave-function model, analyzing key scattering mechanisms: remote impurities (RI), alloy disorder (AD), surface roughness (SR), acoustic (ac) and piezoelectric (PE) phonons, and longitudinal optical (LO) phonons. The mobility ratio $ R=\mu{fin}/\mu{inf}$ reveals distinct trends: $ R_{RI}$ and $ R_{LO}<$ 1 (long-range Coulomb/inelastic scattering), while $ R_{AD}$ , $ R_{ac}$ , $ R_{PE}$ , $ R_{SR}>$ 1 (static potentials). Finite QWs achieve higher mobility at low temperatures (77 K), narrow widths ($ <$ 100 Å), and low densities, enhanced by high indium content. Conversely, infinite QWs outperform at 300 K due to dominant LO scattering. These findings provide actionable guidelines for optimizing QW-based devices such as HEMTs and lasers across operational regimes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 figures
Modulating Thermometric Performance via Dopant Concentration and Morphology in Luminescence Thermometer Exhibiting Dual Structural Phase Transitions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Malgorzata Kubicka, Maja Szymczak, Maciej Ptak, Damian Szymanski, Vasyl Kinzhybahlo, Marek Drozd, Lukasz Marciniak
Expanding the operational range of luminescent thermometers that utilize thermally induced structural phase transitions in lanthanide-doped materials necessitates the exploration of novel host matrices with diverse thermal behaviors. In line with this objective, the present study offers a comprehensive analysis of the temperature-dependent spectroscopic properties of Li3Sc2(PO4)3:Eu3+. The findings reveal that the studied material undergoes two reversible phase transitions: {\gamma}LT - {\alpha}/\b{eta} phase transition at approximately 160 K, followed by an \b{eta} HT transition around 550 K. These transitions are evidenced by notable alterations in the emission spectra and luminescence decay kinetics of Eu3+ ions. By employing an appropriate luminescence intensity ratio, the sensitivity was determined to be 7.8 % K-1 at 160 K for 0.1%Eu3+ and 0.65 % K-1 at 550 K for 0.5%Eu3+. Furthermore, the study demonstrates that the phase transition temperature in Li3Sc2(PO4)3:Eu3+ can be modulated through variations in dopant ion concentration and annealing conditions, which in turn influence the material’s morphology. These strategies enable the fine-tuning of thermometric performance in phase transition-based luminescent thermometers. To the best of our knowledge, this represents the first report in the literature of a luminescent thermometer exhibiting dual thermal operating ranges.
Materials Science (cond-mat.mtrl-sci)
Micromagnetic Study of the Dipolar-Exchange Spin Waves in Antiferromagnetic Thin Films
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
In antiferromagnets, dipolar coupling is often disregarded due to the cancellation of magnetic moments between the two sublattices, leaving spin-wave dispersion predominantly determined by exchange interactions. However, antiferromagnetic spin waves typically involve a slight misalignment of the magnetic moments on the sublattices, giving rise to a small net magnetization that enables long-range dipolar coupling. In this paper, we investigate the role of this dipolar coupling in spin-wave excitations and its influence on the spin-wave dispersion. Our findings show that: (i) when the Néel vector is perpendicular to the film plane or lies within the film plane and parallel to the wave vector, the dispersion branches can be divided into two groups – those unaffected by the dipolar field and those influenced by it. In these cases, the total magnetic moment remains linearly polarized, but the polarization directions differ between the two types of branches; (ii) when the Néel vector lies in the film plane and is perpendicular to the wave vector, the dipolar interactions affect both types of dispersion branches, leading to their hybridization. This hybridization alters the polarization of the magnetic moment, resulting in elliptical polarization.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
10 pages, 5 figures
Hybridized and Localized 4f Electronic States of Nd-based Intermetallic Compounds in Cubic Symmetry Probed by High-Energy Photoemission
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-21 20:00 EDT
M. Sakaguchi, A. Enomoto, H. Fujiwara, G. Nozue, S. Hamamoto, Y. Torii, T. D. Nakamura, N. U. Sakamoto, K. Yamagami, T. Kiss, Y. Kanai-Nakata, S. Imada, A. Irizawa, A. Yamasaki, A. Higashiya, M. Oura, K. Tamasaku, M. Yabashi, T. Ishikawa, H. Sugawara, H. Amitsuka, T. Yanagisawa, H. Hidaka, A. Sekiyama
We have performed soft and hard X-ray photoemission spectroscopies on NdTi2Al20 and NdBe13 which show antiferromagnetic ordering at low temperatures. The Nd 3d core-level photoemission and Nd 3d-4f valence-band resonant photoemission spectra show finite 4f4 initial-state components in addition to the 4f3 configurations attributed to the c-f hybridization effects in NdTi2Al20, while the 4f3 initial-state components with localized character are dominant in NdBe13. These results imply the emergence of overscreening channel due to the two-channel Kondo effect in NdTi2Al20 through the the strong c-f hybridization effect.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
7 pages, 6 figures
Van der Waals devices for surface-sensitive experiments
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-21 20:00 EDT
Nicolai Taufertshöfer, Corinna Burri, Rok Venturini, Iason Giannopoulos, Sandy Adhitia Ekahana, Enrico Della Valle, Anže Mraz, Yevhenii Vaskivskyi, Jan Lipic, Alexei Barinov, Dimitrios Kazazis, Yasin Ekinci, Dragan Mihailovic, Simon Gerber
In-operando characterization of van der Waals (vdW) devices using surface-sensitive methods provides critical insights into phase transitions and correlated electronic states. Yet, integrating vdW materials in functional devices while maintaining pristine surfaces is a key challenge for combined transport and surface-sensitive experiments. Conventional lithographic techniques introduce surface contamination, limiting the applicability of state-of-the-art spectroscopic probes. We present a stencil lithography-based approach for fabricating vdW devices, producing micron-scale electrical contacts, and exfoliation in ultra-high vacuum. The resist-free patterning method utilizes a shadow mask to define electrical contacts and yields thin flakes down to the single-layer regime via gold-assisted exfoliation. As a demonstration, we fabricate devices from 1$ T-$ TaS$ _2$ flakes, achieving reliable contacts for application of electrical pulses and resistance measurements, as well as clean surfaces allowing for angle-resolved photoemission spectroscopy. The approach provides a platform for studying the electronic properties of vdW systems with surface-sensitive probes in well-defined device geometries.
Strongly Correlated Electrons (cond-mat.str-el), Applied Physics (physics.app-ph)
9 pages (main text), 4 figures. 2-page Supporting Information with 5 additional figures. Submitted to RSC Nanoscale
Electrical, Thermal and Thermoelectric transport in open long-range Kitaev Chain
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Averi Banerjee, Syeda Rafisa Rahaman, Nilanjan Bondyopadhaya
We study electrical, thermal and thermoelectric transport in a hybrid device consisting of a long-range Kitaev chain coupled to two metallic leads at two ends. Electrical and thermal currents are calculated in this device under both voltage and thermal bias conditions. We find that the transport characteristics of the long-range Kitaev chain are distinguishably different from its short-range counterpart, which is well known for hosting zero energy Majorana edge modes under some specific range of values of the model parameters. The emergence of massive Dirac fermions, the absence of gap closing at the topological phase transition point and some special features of the energy spectrum which are unique to the long-range Kitaev chain, significantly alter electrical/thermal current vs. voltage/temperature bias characteristics in comparison with that of the short-range Kitaev chain. These novel transport characteristics of the long-range Kitaev model can be helpful in understanding nontrivial topological phases of the long-range Kitaev chain.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
J. Phys.: Condens. Matter 36 (2024) 015303
Semiregular tessellation of electronic lattices in untwisted bilayer graphene under anisotropic strain gradients
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Zeyu Liu, Xianghua Kong, Zhidan Li, Zewen Wu, Linwei Zhou, Cong Wang, Wei Ji
Two-dimensional (2D) moiré superlattices have emerged as a versatile platform for uncovering exotic quantum phases, many of which arise in bilayer systems exhibiting Archimedean tessellation patterns such as triangular, hexagonal, and kagome lattices. Here, we propose a strategy to engineer semiregular tessellation patterns in untwisted bilayer graphene by applying anisotropic epitaxial tensile strain (AETS) along crystallographic directions. Through force-field and first-principles calculations, we demonstrate that AETS can induce a rich variety of semiregular tessellation geometries, including truncated hextille, prismatic pentagon, and brick-phase arrangements. The characteristic electronic bands (Dirac and flat bands) of the lattice models associated with these semiregular tessellations are observed near the Fermi level, arising from interlayer interactions generated by the redistribution of specific stacking registries (AB, BA, and SP). Furthermore, the electronic kagome, distorted Lieb, brick-like, and one-dimensional stripe lattices captured in real-space confirm the tunable nature of the semiregular tessellation lattices enabled by AETS. Our study identifies AETS as a promising new degree of freedom in moiré engineering, offering a reproducible and scalable platform for exploring exotic electronic lattices in moiré systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Theoretical investigation of interface atomic structure of graphene on NiFe alloy substrate
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Naohiro Matsumoto, Ryusuke Endo, Mitsuharu Uemoto, Tomoya Ono
Two processes have been proposed to fabricate graphene/NiFe alloy interfaces for tunneling magnetoresistance devices. One is the transfer of graphene and the other is the evaporation of alloys onto graphene. The formation energy of a NiFe alloy substrate and the adsorption energy of graphene on the NiFe alloy substrate are investigated by a density functional theory calculations to reveal the difference in the atomic structure of the interface between the two processes. It is found that Ni-rich surfaces are preferable for the bare substrate, whereas Fe surfaces are stable for the graphene adsorbed on the substrate. This result indicates that the composition ratio of the surface layer depends on the interface fabrication process.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
17 pages, 7 figures
Non-monotonic dependence of $T_c$ on the c axis compression in the HTSC cuprate La$_{2-x}$Sr$_x$CuO$_4$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-21 20:00 EDT
I. A. Makarov (1), S. G. Ovchinnikov (1) ((1) Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Russia, Krasnoyarsk)
The effect of the the $ c$ axis compression on the electronic structure and superconducting properties of the HTSC cuprate La$ {2-x}$ Sr$ x$ CuO$ 4$ at different doping is investigated. The electronic structure of quasiparticle excitations is obtained within the effective five-band Hubbard model using the equation of motion method for Green’s functions builded on the Hubbard operators. The superconducting gap and $ {T_c}$ are calculated taking into account the exchange pairing mechanism involving not only the Zhang-Rice singlet but also excited two-hole triplet and singlet states. The energy of the $ a{1g}$ orbitals increases with increasing compression and the $ a{1g}$ quasiparticle bands begin to strongly interact with the $ b{1g}$ bands at the top of the valence band. The reconstruction of the region of states determining the superconducting properties results in the high density of states near the Fermi level. This mechanism leads to an increase in $ T_c$ in the underdoped region with increasing compression. The pairing constants renormalizations under compression results in $ {T_c}$ decreasing. The competition of these two effects leads to non-monotonic behavior of $ T_c$ under the $ c$ -axis compression near optimal doping.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
17 pages, 9 figures
Carrier Thermalization and Biexciton Formation in a Polar ZnO/Zn${0.84}$Mg${0.16}$O Quantum Well Probed by Ultrafast Broadband Spectroscopy
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Daniel O. Siebadji Tchuimeni, Marc Ziegler, Olivier Crégut, Pierre Gilliot, Christian Morhain, Andrea Balocchi, Mathieu Gallart
We investigate the ultrafast dynamics of excitons in a 2.6 nm-thick $ \mathrm{ZnO/Zn_{0.84}Mg_{0.16}O}$ quantum well grown on a c-axis sapphire substrate, using non-degenerate time-resolved pump-probe spectroscopy. A pump pulse at 266 nm generates photocarriers within the ZnMgO barriers, and their dynamics is monitored through time-resolved differential reflectance measurements using a supercontinuum probe spanning the 345-400 nm spectral range. Photocarriers generated in the barriers rapidly relax into the quantum well, where they form excitons within sub-picosecond timescales. These excitons quickly thermalize and become localized, likely due to interface disorder or well-width fluctuations, as supported by photoluminescence measurements showing a clear Stokes shift and the absence of free exciton emission. A phonon-assisted absorption process, leading to the effective thermalization of excitons, is observed and analyzed. We identify moreover a negative differential reflectance feature as a photoinduced absorption into a biexciton state, with a binding energy ranging from 18 to 22 meV depending on temperature.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
9 pages, 12 figures
Scalable alloy-based sputtering of high-conductivity PdCoO2 for advanced interconnects
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Takayuki Harada, Zuin Ping Lily Ang, Yuki Sakakibara, Takuro Nagai, Yasushi Masahiro
As integrated circuits continue to scale down, the search for new metals is becoming increasingly important due to the rising resistivity of traditional copper-based interconnects. A layered oxide PdCoO2 is one of the candidate materials for interconnects, having bulk ab-plane conductivity exceeding that of elemental Al. Despite its potential, wafer-scale vacuum deposition of PdCoO2, crucial for interconnect applications, has not yet been reported. In this study, we succeeded in the scalable growth of c-axis oriented PdCoO2 thin films via reactive sputtering from Pd-Co alloy targets. Our method paves the way to harness the unique properties of PdCoO2 in semiconductor devices.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
The following article has been accepted by Applied Physics Letters
Reactive Glass Metal Interaction under Ambient Conditions Enables Surface Modification of Gold Nanoislands
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Sinorul Haque, Shweta R. Keshri, G. Ganesh, Kaustuv Chatterjee, Shubhangi Majumdar, Sudheer Ganisetti, Indrajeet Mandal, Dudekula Althaf Basha, Prabir Pal, Pramit K Chowdhury, Niharika Joshi, Subrahmanyam Sappati, Nitya Nand Gosvami, Eswaraiah Varrla, N. M. Anoop Krishnan, Amarnath R. Allu
Stabilizing gold nanoparticles with tunable surface composition via reactive metal support interactions under ambient conditions remains a significant challenge. We discovered that a reactive glass metal interaction (RGMI) under ambient conditions, driven by the intrinsic catalytic activity of gold nanoislands (GNIs) and the unique properties of sodium aluminophosphosilicate glass, including its chemical composition, molar volume, and high Na ion mobility, enables the formation of robustly anchored GNIs with altered surface compositions. Comprehensive characterization reveals that the adsorption of Na and P at the GNI surfaces induces lattice distortions in the Au(111) planes. Additionally, a smooth GNI glass interface significantly influences the hot carrier dynamics of the GNIs. Altogether, RGMI presents a versatile strategy for engineering stable, multi element nanostructures with potential applications in heterogeneous catalysis, sensing, and optoelectronics.
Materials Science (cond-mat.mtrl-sci)
46, Pages, 5 figures, 30 Supplementary Figures
Atomic Topology and Magnetic Microstructure of Highly Mobile Type I and Supermobile Type II Twin Boundaries in 10M Ni-Mn-Ga Single Crystal
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Ladislav Straka, Marek Vronka, Jan Maňák, Petr Veřtát, Hanuš Seiner, Oleg Heczko
The atomic topology and magnetic microstructure of individual, highly mobile Type I and Type II twin boundaries in 10M Ni-Mn-Ga martensite were investigated by transmission electron microscopy (TEM). The twin boundaries established in a bulk single crystal showed twinning stresses of ~1 MPa for Type I and ~0.1 MPa for Type II twin boundaries. TEM lamellae with a (010) cross-section, their c-axis (easy-magnetization direction) lying in-plane, were prepared by focused ion-beam milling, each containing a single twin boundary of specific type. High-resolution TEM confirmed an atomically sharp Type I twin boundary oriented along the rational (101) plane. The Type II boundary was also atomically sharp, apart from occasional single-atomic-plane steps. This contrasts with previous suggestions of its diffuse nature. Lorentz TEM showed 180° domain walls within martensite variants. The magnetic induction reorients sharply on both twin boundaries, forming 90°-like magnetic domain walls that follow the c-axis easy-magnetization direction.
Materials Science (cond-mat.mtrl-sci)
12 pages, 4 figures
Relating thermodynamic quantities of convex-hard-body fluids to the body’s shape
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-21 20:00 EDT
Thomas Franosch, Cristiano De Michele, Rolf Schilling
For a fluid of convex hard particles, characterized by a length scale $ \sigma_\text{min}$ and an anisotropy parameter $ \epsilon$ , we develop a formalism allowing one to relate thermodynamic quantities to the body’s shape. In a first step its thermodynamics is reduced to that of spherical particles. The latter have a hard core of diameter $ \sigma_\text{min }$ and a soft shell with a thickness $ \epsilon \sigma_\text{min}/2$ . Besides their hard core repulsion at $ \sigma_\text{min }$ they interact by effective entropic forces which will be calculated. Based on this mapping, a second step provides a perturbative method for the systematic calculation of thermodynamic quantities with the shape anisotropy $ \epsilon$ as smallness parameter.
In leading order in $ \epsilon $ , the equation of state is derived as a functional of the particle’s shape. To illustrate these findings, they are applied to a one- and two-dimensional fluid of ellipses and compared with results from different analytical approaches, and our computer simulations. The mapping to spherical particles also implies that any phase transition of spherical particles, e.g., the liquid-hexatic transition, also exists for the nonspherical ones, and shifts linearly with $ \epsilon $ for weak shape anisotropy. This is supported by our Monte-Carlo simulation.
Statistical Mechanics (cond-mat.stat-mech)
26 pages, 11 figures, accepted in Physical Review Research
Spin-Meissner effect in systems of coupled polariton condensates
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
I. Yu. Chestnov, A. Kudlis, A. V. Nalitov, I. A. Shelykh
We theoretically investigate the interplay between Zeeman splitting and TE-TM-induced spin-flip tunneling in coupled exciton-polariton condensates systems and its impact on the spin-Meissner effect. We demonstrate that although a single condensate exhibits the effect of full paramagnetic screening via spin-anisotropic interactions, the inter-site spin-flip tunneling can dramatically alter this behavior. The geometry of the system is shown to play a crucial role. In particular, in a dyad, the chemical potential reveals quadratic scaling with the magnetic field. In a triangle, the competition between Zeeman and TE-TM splittings produces a rich phase diagram that features asymmetric polarization states corresponding to both positive and negative magnetic susceptibility. In a square configuration, the symmetry of the network can restore the spin-Meissner effect, so that the condensate emission frequency becomes magnetic field independent in an extended parameter range. These findings not only shed light on the fundamental physics of polariton lattices but also suggest promising avenues for engineering robust spin-controlled photonic devices and polaritonic simulators.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 6 figures
Large, ultra-flat optical traps for uniform quantum gases
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-21 20:00 EDT
Kai Frye-Arndt, Matthew Glaysher, Marius Glaeser, Matthias Koch, Stefan Seckmeyer, Holger Ahlers, Waldemar Herr, Naceur Gaaloul, Christian Schubert, Ernst Rasel
Ultracold atomic gases with uniform density can be created by flat-bottom optical traps. These gases provide an ideal platform to study many-body physics in a system that allows for simple connections with theoretical models and emulation of numerous effects from a wide range of fields of physics. In Earth-bound laboratories the trap sizes, number of species and states, as well as the range of physical effects are largely restricted by the adopted levitation technique. Homogeneous ultracold gases in microgravity simulators and space however offer an interesting perspective which is actively being pursued. To exploit the full potential of any gravity-compensated laboratory the box potentials created need to be as large as possible. By using two orthogonally aligned acousto-optic deflectors, we create large time-averaged optical potentials with trapping volumes a thousandfold larger than conventional setups, described by power-law scalings with exponents of up to $ 152$ . We verify the performance of our setup by simulating the mean-field behaviour of a quantum gas ground state in conjunction with dynamical excitations due to the realistic time-dependent painting potentials. The implementation of this setup may open new directions at the interface with condensed matter, few-body Efimov physics or the exploration of critical, non-equilibrium phenomena.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph)
Poleval: A Python package for HAXPES analysis
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Robin Yoël Engel, Patrick Lömker
POLEVAL provides a software toolbox for collaborative, persistent and reproducible analysis of XPS experiments. It allows to treat, analyse and visualise the results of an extended experimental campaign in a single python notebook in a consistent manner. Managing experimental data in adequate objects enables experimentalists to process and analyse measurements in very few lines of code, so as to provide decision aids through online data analysis during e.g. beamtime experiments. The persistent and self-documentary style of the notebook-based analysis allows for easy communication of intermediate results and enables progressive refinements into publishable figures or exporting the results to other programs. The toolbox facilitates various routines for data treatment (normalization, cropping, etc.) and aggregation of spectra into groups to analyse trends. It also enables quantitative analysis with three major functions: First, normalization to the photoionization cross-section and probability of emission into the analyser cone allows for quantitative comparisons between intensities from different core levels. The integrated haxquantpy package allows easy retrieval of literature values for this purpose. Second, an extensive fitting functionality is implemented to treat groups of spectra together, rather than spectrum-by-spectrum. This grouping allows reinforcing the fit algorithm with prior knowledge, such as the equivalence of peak widths or positions between spectra, which enables for more consistent, and importantly, more confident fit results for sets of potentially noisy spectra. Third, a simple formalism to estimate the thickness of adsorbate layers based on the ratio between the substrate’s and adsorbate’s XPS signal is implemented.
Materials Science (cond-mat.mtrl-sci), Data Analysis, Statistics and Probability (physics.data-an)
4 pages, 2 figures; submitted to JOSS; Software available at: this https URL
Parallel Exploration of the Optoelectronic Properties of (Sb,Bi)(S,Se)(Br,I) Chalcohalides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Rasmus S. Nielsen, Ángel Labordet Álvarez, Axel G. Medaille, Ivan Caño, Alejandro Navarro-Güell, Cibrán L. Álvarez, Claudio Cazorla, David R. Ferrer, Zacharie J. Li-Kao, Edgardo Saucedo, Mirjana Dimitrievska
Chalcohalides are an emerging family of semiconductors with irresistible material properties, shaped by the intricate interplay between their unique structural chemistry and vibrational dynamics. Despite their promise for next-generation solar energy conversion devices, their intrinsic optoelectronic properties remain largely unexplored. Here, we focus on the (Sb,Bi)(S,Se)(Br,I) system, a subset of compounds that share the same quasi-1D crystal structure. Using a two-step physical vapor deposition (PVD) process, we synthesize the eight ternary chalcohalide compounds, demonstrating bandgaps ranging from 1.38 to 2.08 eV with sharp, single-component photoluminescence (PL) peaks. In a parallel exploration of carrier dynamics and intrinsic electron-phonon interactions – comprehensively studied using power-, temperature-dependent, and time-resolved PL measurements – we map their direct impact on optoelectronic performance. Supported by first-principles density functional theory (DFT) defect calculations, we establish clear structure-property relations, identifying solid-solutions engineering as an effective means to fine-tune the native phonon structures and further suppress non-radiative recombination. This study provides a blueprint for optimizing chalcohalides as high-efficiency materials across a wide range of optoelectronic applications.
Materials Science (cond-mat.mtrl-sci)
Quantum stochastic resonance in a single-photon emitter
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
H. Mannel, J. Zöllner, E. Kleinherbers, M. Zöllner, N. Schwarz, F. Rimek, A. D. Wieck, A. Ludwig, A. Lorke, J. König, M. Geller
Stochastic resonance is a phenomenon in which fluctuations enhance an otherwise weak signal. It has been found in many different systems in paleoclimatology, biology, medicine, and physics. The classical stochastic resonance due to thermal noise has recently been experimentally extended to the quantum regime, where the fundamental randomness of individual quantum events provides the noise source. Here, we demonstrate quantum stochastic resonance in the single-electron tunneling dynamics of a periodically driven single-photon emitter, consisting of a self-assembled quantum dot that is tunnel-coupled to an electron reservoir. Such highly-controllable quantum emitters are promising candidates for future applications in quantum information technologies. We monitor the charge dynamics by resonant optical excitation and identify quantum stochastic resonance with the help of full counting statistics of tunneling events in terms of the Fano factor and extend the statistical evaluation to factorial cumulants to gain a deeper understanding of this far-reaching phenomenon.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Topological electron and phonon flat bands in novel kagome superconductor XPd5 (X=Ca, Sr, Ba)
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-21 20:00 EDT
Jiefeng Ye, Zhigao Huang, Xianxin Wu, Jian-Min Zhang
Fermionic and bosonic localized states induced by geometric frustration in the kagome lattice provide a distinctive research platform for investigating emergent exotic quantum phenomena in strongly correlated systems. Here, we report the discovery of coexisting electronic and phononic flat bands induced by geometric frustration in a novel kagome superconductor XPd5 (X=Ca, Sr, Ba). The electronic flat band is located around the Fermi level and possesses a nontrivial topological invariant with Z2=1. Additionaly, we identify multiple van Hove singularities (vHS) arise from the kagome Pd d orbitals with distinct dispersion and sublattice features, including conventional, higher-order vHS and p-type, m-type vHS. Specifically, our investigation of the vibrational modes of the phononic flat band reveals that its formation originates from destructive interference between adjacent kagome lattice sites with antiphase vibrational modes. A spring-mass model of phonons is established to probe the physical mechanism of the phononic flat bands. Furthermore, the calculations of electron-phonon coupling in the XPd5 reveal superconducting ground states with critical temperatures (Tc) of 4.25 K, 2.75 K, and 3.35 K for CaPd5, SrPd5, and BaPd5, respectively. This work provides a promising platform to explore the Fermion-boson many-body interplay and superconducting states, while simultaneously establishing a novel analytical framework to elucidate the origin of phononic flat bands in quantum materials.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
9 pages, 5 figures, 2 tables
A General Algorithm For Determining The Conductivity Zeros In Large Molecular Nanostructures: Applications To Rectangular Graphene Sheets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Marian Nita, Mugurel Tolea, Catalina Marinescu
We propose an algorithm for determining the zeros of the electric conductivity in large molecular nanonstructures such as graphene sheets. To this end, we employ the inverse graph method, whereby non-zeros of the Green’s functions are represented graphically by a segment connecting two atomic sites, to visually signal the existence of a conductance zero as a line that is missing. In rectangular graphene structures the topological properties of the inverse graph determine the existence of two types of Green’s function zeros that correspond to absolute conductance cancellations with distinct behavior in the presence of external disorder. We discuss these findings and their potential applications in some particular cases.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Journal of Physics: Condensed Matter 2025
Path-integral molecular dynamics with actively-trained and universal machine learning force fields
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
A. A. Solovykh (1, 2 and 3), N. E. Rybin (3 and 4), I. S. Novikov (3, 5, 6 and 7), A. V. Shapeev (3 and 4) ((1) Lomonosov Moscow State University, Faculty of Physics, Moscow, Russian Federation, (2) Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russian Federation, (3) Skolkovo Institute of Science and Technology, Moscow, Russian Federation, (4) Digital Materials LLC, Odintsovo, Russian Federation, (5) HSE University, Faculty of Computer Science, Moscow, Russian Federation, (6) Moscow Institute of Physics and Technology, Moscow, Russian Federation, (7) Emanuel Institute of Biochemical Physics of the Russian Academy of Sciences, Moscow, Russian Federation)
Accounting for nuclear quantum effects (NQEs) can significantly alter material properties at finite temperatures. Atomic modeling using the path-integral molecular dynamics (PIMD) method can fully account for such effects, but requires computationally efficient and accurate models of interatomic interactions. Empirical potentials are fast but may lack sufficient accuracy, whereas quantum-mechanical calculations are highly accurate but computationally expensive. Machine-learned interatomic potentials offer a solution to this challenge, providing near-quantum-mechanical accuracy while maintaining high computational efficiency compared to density functional theory (DFT) calculations. In this context, an interface was developed to integrate moment tensor potentials (MTPs) from the MLIP-2 software package into PIMD calculations using the i-PI software package. This interface was then applied to active learning of potentials and to investigate the influence of NQEs on material properties, namely the temperature dependence of lattice parameters and thermal expansion coefficients, as well as radial distribution functions, for lithium hydride (LiH) and silicon (Si) systems. The results were compared with experimental data, quasi-harmonic approximation calculations, and predictions from the universal machine learning force field MatterSim. These comparisons demonstrated the high accuracy and effectiveness of the MTP-PIMD approach.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG), Computational Physics (physics.comp-ph)
9 pages, 6 eps figures
In-situ observation of elastic instability of stress-induced B19$^\prime$ martensite in thin NiTi wires
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Petr Sedlák (1), Miroslav Frost (1), Martin Ševčík (1), Lukáš Kadeřávek (2), Hanuš Seiner (1) ((1) Institute of Thermomechanics, Czech Academy of Sciences, Prague, (2) FZÚ - Institute of Physics, Czech Academy of Sciences, Prague)
A laser-ultrasonic approach was used to measure elastic properties of a superelastic nickel-titanium wire with the aim to evaluate their evolution with stress and temperature in stress-induced martensite. It was observed that this evolution can be well described by a single smooth surface in the stress-temperature space, with the values of Young’s modulus ranging from 30 to 50 GPa. The evolution of the modulus was then monitored in-situ with further heating under fixed strain, that is, during the shape setting. The results revealed that the martensite phase experienced further softening during this process, reaching Young’s modulus of nearly 10 GPa at high temperatures and high stresses. In addition, the measurement enabled a direct detection of the initiation and termination temperatures of the shape setting from the elasticity data, which was used to show that it occurs in the same temperature interval for tension-induced and torsion-induced martensite.
Materials Science (cond-mat.mtrl-sci)
Manuscript submitted to Shape Memory and Superelasticity
Insight into the Correlation of Shape and Magnetism of Hematite Nanospindles
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Juri Kopp, Gerald Richwien, Markus Heidelmann, Soma Salamon, Benoît Rhein, Annette M. Schmidt, Joachim Landers
It is established that the Morin transition, a spin reorientation in hematite, is shifted to lower temperatures with decreasing nanoparticle volume. However, our findings indicate an opposite effect in a series of hematite nanospindles: The particles, synthesized by hydrothermal decomposition of iron(III) chloride solution, with aspect ratios $ p$ between $ 1.0$ and $ 5.2$ (long axis ca. $ 70$ –$ 290$ nm) display decreasing Morin transition temperatures $ T_{\text{Morin}}$ upon increasing $ p$ , despite the volume increase. Their inner morphology, determined via (HR)STEM and XRD, shows that they are formed by the epitactical fusion of primary particles, perfectly aligned in terms of crystallographic orientation. Combining magnetometry and Mössbauer spectroscopy, we uncover the correlation between particle shape, magnetic properties, and in particular the Morin transition: While more spherical particles undergo said transition at about $ 200$ K, $ T_{\text{Morin}}$ decreases upon higher nanospindle elongation, while also being broadened and showing a wider thermal hysteresis. Our measurements reveal complete suppression of the Morin transition beyond a critical threshold $ p \gtrapprox 1.5$ , indicating stabilization of the weak ferromagnetic (WFM) state with net particle magnetic moment within the hematite basal plane, despite such behavior being unexpected based on shape anisotropy considerations. For the correlated, magnetic field-dependent spin-flop transition, a comparable trend in particle aspect ratio is detected. We have demonstrated the presence of intermediate spin alignment states that deviate both from the low-temperature antiferromagnetic (AFM) and high-temperature WFM spin structure for slightly elongated particles, likely being connected to the suppression of the Morin transition observed for $ p \gtrapprox 1.5$ .
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
44 pages, 10 figures in main text, 10 figures in supplementary information, submitted in The Journal of Physical Chemistry
Charge and magnetic orders in a two-band model with long-range interactions for infinite-layer nickelates NdNiO$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-21 20:00 EDT
Tharathep Plienbumrung, Jean-Baptiste Morée, Andrzej M. Oleś, Maria Daghofer
We present an effective two-band model for infinite-layer nickelates NdNiO$ _2$ that consisting of a $ d$ band centered at Ni site and an interstitial $ s$ -like band centered at Nd site. To the large extent of the wave functions, we find intersite Coulomb interactions to be substantial. We then use the variational cluster approach together with mean-field theory to investigate magnetic and charge ordering. While tendencies towards charge modulation are found, they are weak and might be due to finite-size effects. Magnetic order is determined mostly by the filling of the $ d$ band and hardly affected by including longer-ranged interactions. For a $ d$ -band density consistent with density-functional theory, magnetic ordering vanishes once quantum fluctuations are included to a sufficient spatial extent. Apart from self-doping, $ d$ and $ s$ bands remain largely uncoupled despite the presence of inter-orbital Coulomb interaction and (small) inter-orbital hopping.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
11 pages, 10 figures
Infrared markers of topological phase transitions in quantum spin Hall insulators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Paolo Fachin, Francesco Macheda, Paolo Barone, Francesco Mauri
Using first principles techniques, we show that infrared optical response can be used to discriminate between the topological and the trivial phases of two-dimensional quantum spin Hall insulators (QSHI). We showcase germanene and jacutingaite, of recent experimental realization, as prototypical systems where the infrared spectrum is discontinuous across the transition, due to sudden and large discretized jumps of the value of Born effective charges (up to 2). For these materials, the topological transition can be induced via the application of an external electrostatic potential in the field-effect setup. Our results are rationalized in the framework of a low-energy Kane-Mele model and are robust with respect to dynamical effects which come into play when the energy gap of the material is of the same order of the infrared active phonon frequency. In the small gap QSHI germanene, due to dynamical effects, the in-plane phonon resonance in the optical conductivity shows a Fano profile with remarkable differences in the intensity and the shape between the two phases. Instead, the large gap QSHI jacutingaite presents several IR-active phonon modes whose spectral intensities drastically change between the two phases.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Localization versus hybridization of $f$ states in actinide and lanthanide dioxides probed in core-level photoemission spectra
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-21 20:00 EDT
The degrees of the localization and hybridization of the valence $ f$ states/covalency of the chemical bonding in actinide and lanthanide dioxides were investigated using the atomic, crystal-field multiplet and Anderson impurity model (AIM) approaches to calculate actinide $ 5d$ and lanthanide $ 3d$ x-ray photoemission spectra (XPS). The actinide $ 5d$ XPS can be largely described within atomic, crystal-field multiplet theory due to an extended multiplet structure as a result of the strong interaction of $ 5f$ electrons with a $ 5d$ core hole. The multiplet structure was found to be quite sensitive to the oxidation state of actinides. In turn, the lanthanide $ 3d$ XPS description requires the AIM-type of calculations due to significant $ 4f-$ O $ 2p$ hybridization effects. As a result derived from the analysis of the XPS spectra, an increase in the $ f$ -shell occupancy in the ground state due to the $ f-$ O $ 2p$ hybridization and covalency of the chemical bonding appears to be higher in lanthanide dioxides as compared to actinide dioxides.
Strongly Correlated Electrons (cond-mat.str-el)
Spin relaxation in a single-electron bilayer graphene quantum dot
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
We study the spin relaxation in a single-electron bilayer graphene quantum dot due to the spin-orbit coupling. The spin relaxation is assisted by the emission of acoustic phonons via the bond-length change and deformation potential mechanisms and $ 1/f$ charge noise. In the perpendicular magnetic-field dependence of the spin relaxation rate $ T_1^{-1}$ , we predict a monotonic increase of $ T_1^{-1}$ at higher fields where the electron-phonon coupling via the deformation potential plays a dominant role in spin relaxation. We show a less pronounced dip in $ T_1^{-1}$ at lower magnetic fields due to the competition between the electron-phonon coupling due to bond-length change and $ 1/f$ charge noise. Finally, detailed comparisons of the magnetic-field dependence of the spin relaxation with the existing experiments by Banszerus et al. [Nat. Commun. 13, 3637 (2022)] and Gächter et al. [PRX Quantum 3, 020343 (2022)] are reported.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
5 pages, 3 figures
Water-rich amorphous state from drying mixed-metal sulfate solutions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Christiaan T. van Campenhout, Romane Le Dizès Castell, Tess Heeremans, Sander Woutersen, Daniel Bonn, Noushine Shahidzadeh
Amorphous and glassy materials are important for many advanced applications, from flexible solar cells to drug delivery systems. To this end, new glasses are in high demand, but precise chemical design of amorphous materials remains challenging. By studying the crystallization of mixed salt solutions, we have discovered an entirely new type of amorphous material: water-rich amorphous mixed sulfates. Specifically, we show that drying of sulfate salt mixtures of both mono- and higher valency cations almost exclusively yields a glassy or amorphous state, where the stability of the amorphous state depends on the cations present and ranges from seconds to months. Furthermore, we show that the glassy state is viscoelastic, behaves like a soft solid (G’ 10^5 - 10^6 Pa), retains a large amount of water (30 to 40 weight percent), and is X-ray amorphous. Additionally, confocal Raman microspectroscopy reveals disordered sulfate orientations and Fourier-transform infrared spectroscopy highlights increased hydrogen bonding during drying, which together with strong cation hydration is hypothesized to prevent crystallization. These results provide insights for the production of a new class of amorphous materials, and help to elucidate the mystery of the high abundance of such amorphous salts found on Mars.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)
Freezing line of polydisperse hard spheres via direct-coexistence simulations
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Antoine Castagnède, Laura Filion, Frank Smallenburg
In experimental systems, colloidal particles are virtually always at least somewhat polydisperse, which can have profound effects on their ability to crystallize. Unfortunately, accurately predicting the effects of polydispersity on phase behavior using computer simulations remains a challenging task. As a result, our understanding of the equilibrium phase behavior of even the simplest colloidal model system, hard spheres, remains limited. Here, we present a new approach to map out the freezing line of polydisperse systems that draws on direct-coexistence simulations in the semi-grand canonical ensemble. We use this new method to map out the conditions where a hard-sphere fluid with a Gaussian size distribution becomes metastable with respect to partial crystallization into a face-centered-cubic crystal. Consistent with past predictions, we find that as the polydispersity of the fluid increases, the coexisting crystal becomes increasingly size-selective, exhibiting a lower polydispersity and larger mean particle size than the fluid phase. Interestingly, for sufficiently high polydispersity, this leads to a crystal phase with a lower number density than that of the coexisting fluid. Finally, we exploit our direct-coexistence simulations to examine the characteristics of the fluid-crystal interface, including the surface stress and interfacial absorption.
Soft Condensed Matter (cond-mat.soft)
phaser: An all-in-one package for (multislice) electron ptychography
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Colin Gilgenbach, James M. LeBeau
Electron ptychography is a groundbreaking technique for the advanced characterization of materials. Successful ptychography relies on robust implementations of reconstruction algorithms with process raw data into phase images. Current software has enabled deep sub-angstrom multislice electron ptychographic reconstructions, but reconstructions remain challenging and computationally expensive. In addition, current software generally lacks the modularity to act as a platform for the development and testing of new solver components and algorithms. For instance, algorithms based on gradient descent and autodifferentiation promise faster reconstructions with higher quality, but it is difficult to implement these algorithms in existing software. Here, we present \texttt{phaser}, an open source Python package which provides a unified interface to both conventional and gradient descent based ptychographic algorithms. Reconstructions are specified in a declarative format, and can be run from a command line, Jupyter notebook, or web interface. Multiple computational backends are supported to provide maximum flexibility. With the JAX computational backend, a 6x improvement in iteration speed is achieved over a state-of-the-art package, \texttt{fold_slice}. Additionally, \texttt{phaser}’s gradient descent solver achieves improved reconstruction quality.
Materials Science (cond-mat.mtrl-sci)
Role of Friction on the Formation of Confined Granular Structures
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Vinícius Pereira da S. Oliveira, Danilo S. Borges, Erick M. Franklin, Jorge Peixinho
Metastable systems of fluidized grains can auto-defluidize after some time, the settling particles forming either a glass- or crystal-like structure. We carried out experiments using different polymer spheres, of known friction and roughness, fluidized in water. We show that the level of velocity fluctuations is higher for the high friction material. A diagram was obtained for the settled particles when the coefficient of friction is of the order of 0.1, and their structure is characterized through an analysis of the nearest neighbors’ angles. For the lower friction values, we find that the number of defects is smaller, the contact chains being longer and aligned. Our results bring new insights for understanding the formation of glass- and crystal-like structures based on the material surface properties.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
7 pages, 7 figures
Reference lattice, sound, stiffness, and magnetic transitions of Ising monolayers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
John M. Davis, Amador Garcia-Fuente, Jaime Ferrer, Salvador Barraza-Lopez
A reference lattice, away from which elastic distortions induced by the spin texturing of 2D magnets take hold, is motivated from a picture of pairwise Biot-Savart interactions among identical solenoids that either elongate or compress a (``zero-current’’) spring lattice. Applied to a paradigmatic CrSiTe$ _3$ monolayer (ML), the reference is given by the average between the atomic positions of FM and Néel AFM lattices; such an atomic disposition permits understanding structural distortions and elastic energies due to magnetism readily. Furthermore, the anisotropic speed of sound in the magnetic ground state explains an observed anisotropy of vibrational frequencies on similar magnets. Elastic stiffness constants are reported, too. Magnetic energies in four Ising structural configurations were calculated, and the strain needed for those 2D magnets to undergo an AFM to FM quantum phase transition was determined as well.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
5 pages, 4 figures
Thermal conductivity of boron arsenide above 2100 watts per meter per Kelvin at room temperature
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Ange Benise Niyikiza, Zeyu Xiang, Fanghao Zhang, Fengjiao Pan, Chunhua Li, David Broido, Ying Peng, Bolin Liao, Zhifeng Ren
Boron arsenide (BAs) single crystals had been previously reported to have thermal conductivity of 1500 W/mK at room temperature. Now we achieved thermal conductivity above 2100 W/mK at room temperature in BAs crystals due to much lower concentration of impurities Si, C, and O grown from purified arsenic. We also observed a T-1.8 dependence of the thermal conductivity, suggesting a more significant contribution from four-phonon scatterings than suggested by previous theory. We found that our experimental result can be fit with a modified theoretical calculation by tuning down the three-phonon scattering for phonons in the 4-8 THz range, although current phonon transport theory cannot provide a physical explanation. Such an advance will not only attract more effort on growing BAs single crystals and studying their practical applications but also stimulate theoretical work to predict more materials with possibly even higher thermal conductivities.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
The latest research on boron arsenide
Influence of microscopic parameters on phase behavior of a cell model with Curie-Weiss interaction
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-21 20:00 EDT
O.A. Dobush, M.P. Kozlovskii, I.V. Pylyuk, Yu.O. Plevachuk
We have investigated the effect of changing two microscopic parameters in a cell model with Curie-Weiss-type interaction on its phase behavior, namely the cell volume and ratio between repulsion and attraction intensities. The results are based on an exact solution previously derived for this model in the grand canonical ensemble. At sufficiently low temperatures, the cell model exhibits multiple first-order phase transitions. Varying the cell volume and the repulsion-to-attraction ratio, we represent a quantitative comparison of the chemical potential and pressure isotherms, as well as the pressure-temperature and temperature-density phase diagrams. The analysis of provided data shows that altering microscopic parameters does not lead to qualitative changes in the overall phase behavior of the cell model.
Statistical Mechanics (cond-mat.stat-mech)
11 pages, 2 figures
Spin Pumping into two-dimensional systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-21 20:00 EDT
Yuya Ominato, Masaki Yama, Ai Yamakage, Mamoru Matsuo, Takeo Kato
In this review, we present recent theoretical developments on spin transport phenomena probed by ferromagnetic resonance (FMR) modulation in two-dimensional systems coupled to magnetic materials. We first address FMR linewidth enhancements induced by spin pumping at interfaces, emphasizing their potential as sensitive probes of superconducting pairing symmetries in two-dimensional superconductors. We then examine FMR modulation due to spin pumping into two-dimensional electron gases formed in semiconductor heterostructures, where the interplay of Rashba and Dresselhaus spin-orbit interactions enables gate-controlled spin transport and persistent spin textures. Finally, we investigate spin pumping in monolayer transition-metal dichalcogenides, where spin-valley coupling and Berry curvature effects lead to valley-selective spin excitations and a spin-current Hall effect. These developments demonstrate that the spin pumping technique provides a versatile tool for probing spin transport and spin-dependent phenomena in low-dimensional systems, offering a basis for future spintronics applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
37 pages, 12 figures
Acidity-Mediated Metal Oxide Heterointerfaces: Roles of Substrates and Surface Modification
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Gyu Rac Lee, Thomas Defferriere, Jinwook Kim, Han Gil Seo, Yeon Sik Jung, Harry L. Tuller
Although strong modulation of interfacial electron concentrations by the relative acidity of surface additives has been suggested, direct observation of corresponding changes in surface conductivity, crucial for understanding the role of local space charge, has been lacking. Here, we introduce a model platform comprising well-aligned mixed ionic-electronic conducting $ \mathrm{Pr}{0.2}\mathrm{Ce}{0.8}\mathrm{O}{2-\delta}$ nanowire arrays ($ \mathrm{PCO}{\mathrm{NA}}$ ) to show that acidity-modulated heterointerfaces predict electron depletion or accumulation, resulting in tunable electrical properties. We confirm three orders of magnitude increased $ \mathrm{PCO}{\mathrm{NA}}$ conductivity with basic $ \mathrm{Li}{2}\mathrm{O}$ infiltration. Moreover, the relative acidity of the insulating substrate supporting the $ \mathrm{PCO}{\mathrm{NA}}$ strongly influences its electronic properties as well. This strategy is further validated in purely ionic-conducting nanostructured ceria as well as $ \mathrm{PCO}{\mathrm{NA}}$ . We suggest that observed conductivity changes stem not only from acidity-mediated space charge potentials at heterointerfaces but also from grain boundaries, chemically-modulated by cation in-diffusion. These findings have broad implications for how substrate and surface treatment choices can alter the conductive properties of nanostructured functional oxides.
Materials Science (cond-mat.mtrl-sci)
51 pages
Influence of active breathing on rheology and jamming of amorphous solids: insights from microscopic and mesoscale analysis
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Sayantan Ghosh, Magali Le Goff, Pinaki Chaudhuri, Kirsten Martens
We study the flow behavior and unjamming transition in dense assemblies of actively deforming particles that periodically change size, a process that we refer to as breathing. Using extensive molecular dynamics simulations and a complementary mesoscale elasto-plastic model, we explore how this internal activity influences plasticity and rheology. At low amplitudes of breathing, the system remains jammed and displays localized, reversible rearrangements. As the amplitude of the breathing increases beyond a critical threshold, the system undergoes an activity-induced fluidization marked by a surge in plastic events and a drop in yield stress. The flow curve analysis reveals a transition from yield-stress behavior to Newtonian flow at high activity. The mesoscale model captures these trends and provides insight into the role of stress redistribution due to local active deformations. Our findings highlight the potential of internal active driving to tune the mechanical state of amorphous materials without external forcing.
Soft Condensed Matter (cond-mat.soft)
Pressure Waves During Granular Flows in Varying Gravity Environments
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
Abigail Tadlock, Lori McCabe, Kerstin Nordstrom
We present results of LAMMPS Molecular Dynamics simulations of 2D gravity-driven flows of 30,000 soft uniform spheres through a vertical silo. We vary the gravitational field (g), elastic modulus of the particles (E), and silo outlet diameter (D). We present results on upwards pressure waves observed in the system. We compare our results with previous work on granular acoustics. Despite the typical particle speed being substantially less than the measured wave speed, we posit these are nonlinear shock waves, as observed in other systems near jamming. We demonstrate that the wave speeds in all systems appear to follow a power law that is distinct from linear wave expectations.
Soft Condensed Matter (cond-mat.soft)
Electrical manipulation of magnetic domain structure in van der Waals ferromagnetic Fe$_3$GaTe$_2$ using ferroelectric PMN-PT single crystal
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Riku Iimori, Yuta Kodani, Shaojie Hu, Takashi Kimura
Two-dimensional (2D) van der Waals (vdW) ferromagnets have emerged as promising materials for spintronic applications due to their unique magnetic properties and tunability. Controlling ferromagnetism via external stimuli is critical for both fundamental research and device integration. In particular, modulation of magnetic anisotropy and exchange interactions through strain offers a viable pathway for functional control. Owing to their weak interlayer coupling, vdW ferromagnets exhibit pronounced sensitivity to strain, enabling effective tuning of their magnetic states. In this study, we investigate electric-field-induced magnetoelectric coupling in the above-room-temperature vdW ferromagnet Fe$ _3$ GaTe$ _2$ integrated on a ferroelectric PMN-PT substrate. We demonstrate that application of an electric field leads to a substantial reduction in coercive force along with dynamic reconfiguration of the magnetic domain structure. These effects are attributed to electric-field-induced modulation of the vdW interlayer gap and enhancement of the DzyaloshinskiiMoriya interaction. Our findings reveal a strong interplay between electric fields and magnetism in vdW systems, offering a viable route toward the development of low-power, multifunctional magnetic devices. This work establishes a foundation for the electric-field control of magnetic properties in vdW ferromagnets and highlights their potential in next-generation spintronic technologies.
Materials Science (cond-mat.mtrl-sci)
19 pages, 5 figures
Dynamic correlations of frustrated quantum spins from high-temperature expansion
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-21 20:00 EDT
Ruben Burkard, Benedikt Schneider, Björn Sbierski
For quantum spin systems in equilibrium, the dynamic structure factor (DSF) is among the most feature-packed experimental observables. However, from a theory perspective it is often hard to simulate in an unbiased and accurate way, especially for frustrated and high-dimensional models at intermediate temperature. We address this challenge by introducing a dynamic extension of the high-temperature expansion as an efficient numerical approach to the DSF for arbitrary lattices. We focus on the nearest-neighbor Heisenberg model and spin-lengths S=1/2 and 1. We present a user-friendly numerical implementation and provide comprehensive benchmarks on spin chains. As applications we treat a variety of frustrated two- and three dimensional antiferromagnets. In particular we shed new light on the anomalous intermediate temperature regime of the S=1/2 triangular lattice model and reproduce the DSF measured recently for a S=1 pyrochlore material.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Quantum Gases (cond-mat.quant-gas)
see also associated repository: this https URL
Interplay between altermagnetic order and crystal symmetry probed using magnetotransport in epitaxial altermagnet MnTe
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-21 20:00 EDT
Himanshu Bangar, Polychronis Tsipas, Prasanna Rout, Lalit Pandey, Alexei Kalaboukhov, Akylas Lintzeris, Athanasios Dimoulas, Saroj P. Dash
Altermagnets are a new class of magnetic materials characterized by fully compensated spins arranged in alternating local structures, allowing for spin-split bands similar to those found in ferromagnets without net magnetism. Recently, MnTe has emerged as a prototypical altermagnetic material exhibiting spin-polarized electronic bands and anomalous transport phenomena. Although recent work has explored the magnetic and structural properties of MnTe, detailed experimental investigations into the relationship between altermagnetic order and crystal symmetry are lacking. Here, we report the relationship between altermagnetic order and crystal symmetry by investigating magnetotransport properties of MnTe epitaxial altermagnetic thin films grown by molecular beam epitaxy. We observe a spontaneous anomalous Hall effect and show the control of Hall response with the altermagnetic order using the magnetic field and the crystallographic angle dependence. Detailed measurements establish that both the longitudinal and transverse electronic responses depend on the relative orientation of the applied current and Néel vector as well as on the crystal orientation and altermagnetic order. These results provide new insights into the interplay between crystal symmetry and altermagnetism for future device applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el), Applied Physics (physics.app-ph)
Superconducting properties of thin film $\mathrm{Nb_{1-x}Ti_xN}$ studied via the NMR of implanted $^8$Li
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-21 20:00 EDT
Md Asaduzzaman, Ryan M. L. McFadden, Edward Thoeng, Yasmine Kalboussi, Ivana Curci, Thomas Proslier, Sarah R. Dunsiger, W. Andrew MacFarlane, Gerald D. Morris, Ruohong Li, John O. Ticknor, Robert E. Laxdal, Tobias Junginger
We report measurements of the normal-state and superconducting properties of thin-film $ \mathrm{Nb_{1-x}Ti_xN}$ using $ ^{8}$ Li $ \beta$ -detected nuclear magnetic resonance ($ \beta$ -NMR). In these experiments, radioactive $ ^{8}$ Li$ ^{+}$ probes were implanted $ \sim21$ nm below the surface of a $ \mathrm{Nb_{1-x}Ti_xN}$ (91 nm) film in $ \mathrm{Nb_{0.75}Ti_{0.25}N}$ (91 nm)/AlN(4 nm)/Nb and its NMR response recorded (via $ ^{8}$ Li’s $ \beta$ -emissions) between 4.6 K and 270 K in a 4.1 T field applied normal to its surface. Resonance measurements reveal wide, symmetric lineshapes at all temperatures, with significant additional broadening below the film’s superconducting transition temperature $ T_\mathrm{c}(0 ; \mathrm{T}) = 15.4 \pm 0.7$ K due to vortex lattice formation. Fits to a broadening model find a magnetic penetration depth $ \lambda(0 ; \mathrm{K})= 180.57 \pm 0.30$ nm and upper critical field $ B_\mathrm{c2}(0 ; \mathrm{K})= 18 \pm 4$ T, consistent with literature estimates. Spin-lattice relaxation (SLR) measurements find a Korringa response at low temperatures, with dynamic (i.e., thermally activated) contributions dominating above $ \sim100$ K. Below $ T_\mathrm{c}$ , we observe a small Hebel-Slichter coherence peak characterized by a superconducting energy gap $ \Delta(0 ; \mathrm{K}) = 2.60 \pm 0.12$ meV and modest Dynes-like broadening. Our measurements suggest a gap ratio $ 2\Delta(0 ; \mathrm{K})/k_\mathrm{B}T_\mathrm{c}(0 ; \mathrm{T}) = 3.92 \pm 0.25$ , consistent with strong-coupling behavior. Sources for the dynamic high-$ T$ relaxation are suggested.
Superconductivity (cond-mat.supr-con)
Impact of Surfactant and Flow Rate on the Electrical Properties of Activated Carbon Black Suspensions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-21 20:00 EDT
KangJin Lee, Jesse S. Wainright, Christopher L. Wirth
Carbon black slurries are a key component in redox flow batteries as the large surface area provided by the particles allows an increase in the battery capacity without facing limitations posed by many solid-state batteries such as safety hazard or cost. However, these conductive slurries often have complex mechanical and electrical responses because of the heterogeneous nature of the suspensions. Utilization of these slurries in a redox flow battery requires understanding of how additives impact the material responses and associated battery performance. This work focuses on the electrochemical performance of the slurry at flow rate conditions matching those of battery operation. In addition, the impact of a nonionic surfactant (Triton X-100) on the conductivity and capacitance of the slurry was measured. Experimental results show that the full capacitive contribution of the carbon black particles can only be measured at low flow rates and low scan rates, while the conductive contribution can be measured at all scan rates in flowing conditions. Upon the addition of surfactants, there is a gradual decrease in the electrochemical performance with increasing surfactant concentration until the surface of the carbon black particle is saturated. Once saturated, the conductive carbon particles no longer contribute to the electronic conductivity of the slurry. Results presented herein on the electrochemical response of the slurry to the addition of surfactant are in stark contrast to the mechanical response. While previous work has shown a smaller change in the response, followed by a step-change at a critical surfactant concentration, electrochemical data shows a gradual transition. Comparison of these behaviors suggests a difference in the mechanisms for how mechanical networks form in comparison to charge transfer networks for this particular slurry chemistry.
Soft Condensed Matter (cond-mat.soft)
Engineering the Kondo impurity problem with alkaline-earth atom arrays
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-21 20:00 EDT
Adriano Amaricci, Andrea Richaud, Massimo Capone, Nelson Darkwah Oppong, Francesco Scazza
We propose quantum simulation experiments of the Kondo impurity problem using cold alkaline-earth(-like) atoms (AEAs) in a combination of optical lattice and optical tweezer potentials. Within an ab initio model for atomic interactions in the optical potentials, we analyze hallmark signatures of the Kondo effect in a variety of observables accessible in cold-atom quantum simulators. We identify additional terms not part of the textbook Kondo problem, mostly ignored in previous works and giving rise to a direct competition between spin and charge correlations–strongly suppressing Kondo physics. Crucially, we show that the Kondo effect can be restored by locally adjusting the chemical potential on the impurity site. We identify realistic parameter regimes and preparation protocols suited to current experiments with AEA arrays. Our work paves the way for novel quantum simulations of the Kondo problem and offers new insights into Kondo physics in unconventional regimes.
Quantum Gases (cond-mat.quant-gas), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
7+10 pages, 4+4 figures