CMP Journal 2025-08-20
Statistics
Nature: 26
Nature Nanotechnology: 1
Nature Physics: 1
Physical Review Letters: 14
Physical Review X: 2
arXiv: 50
Nature
STING induces ZBP1-mediated necroptosis independently of TNFR1 and FADD
Original Paper | Autoinflammatory syndrome | 2025-08-19 20:00 EDT
Konstantinos Kelepouras, Julia Saggau, Debora Bonasera, Christine Kiefer, Federica Locci, Hassan Rakhsh-Khorshid, Louisa Grauvogel, Ana Beatriz Varanda, Martin Peifer, Elena Loricchio, Antonella Montinaro, Marijana Croon, Aleksandra Trifunovic, Giusi Prencipe, Antonella Insalaco, Fabrizio De Benedetti, Henning Walczak, Gianmaria Liccardi
Conditional deletion of Caspase-8 in epidermal keratinocytes (Casp8E-KO) causes necroptosis-driven lethal dermatitis1-7. Here, we discover that Casp8 loss leads to accumulation of cytosolic DNA responsible for the activation of a cyclic-GMP-AMP synthase (cGAS)/stimulator of interferon (IFN) gene (STING)-mediated transcriptional program. Genetic and biochemical evidence indicate that STING upregulates both Z-DNA binding protein-1 (ZBP1), and mixed lineage kinase domain-like (MLKL). Combined Casp8-deficiency- and STING-activation-driven accumulation of Z-nuclei acids, activates ZBP1 and triggers formation of a ZBP1-RIPK1-RIPK3 complex independently of FADD-RIPK1-RIPK3 complex enabling necroptosis execution. Genetically, we reveal a functional overlap between STING and ZBP1 as drivers of lethal dermatitis independently of TNFR1, uncovering a novel aetiology of necroptotic inflammation. Since gain-of-function mutations in human STING cause STING-Associated Vasculopathy with onset in Infancy (SAVI), we assessed the role of STING-induced necroptosis in SAVI’s aetiology. Chronic activation of STING in patients orchestrates a necroptotic transcriptional program which is confirmed in the N153S-SAVI preclinical mouse model where immune cell-driven pathology and lethality are remarkably rescued by RIPK3 co-deletion. These findings establish STING-driven ZBP1-mediated necroptosis as a central pathogenic mechanism in both Casp8-deficient inflammation and SAVI and suggest that targeting the ZBP1-RIPK3-MLKL axis holds therapeutic potential for interferonopathies characterised by excessive necroptosis.
Autoinflammatory syndrome, Immune cell death, Necroptosis
Structural basis for the dynamic regulation of mTORC1 by amino acids
Original Paper | Cryoelectron microscopy | 2025-08-19 20:00 EDT
Max L. Valenstein, Maximilian Wranik, Pranav V. Lalgudi, Karen Y. Linde-Garelli, Yuri Choi, Raghu R. Chivukula, David M. Sabatini, Kacper B. Rogala
The mechanistic target of rapamycin complex 1 (mTORC1) anchors a conserved signalling pathway that regulates growth in response to nutrient availability1,2,3,4,5. Amino acids activate mTORC1 through the Rag GTPases, which are regulated by GATOR, a supercomplex consisting of GATOR1, KICSTOR and the nutrient-sensing hub GATOR2 (refs. 6,7,8,9). GATOR2 forms an octagonal cage, with its distinct WD40 domain β-propellers interacting with GATOR1 and the leucine sensors Sestrin1 and Sestrin2 (SESN1 and SESN2) and the arginine sensor CASTOR1 (ref. 10). The mechanisms through which these sensors regulate GATOR2 and how they detach from it upon binding their cognate amino acids remain unknown. Here, using cryo-electron microscopy, we determined the structures of a stabilized GATOR2 bound to either Sestrin2 or CASTOR1. The sensors occupy distinct and non-overlapping binding sites, disruption of which selectively impairs the ability of mTORC1 to sense individual amino acids. We also resolved the apo (leucine-free) structure of Sestrin2 and characterized the amino acid-induced structural rearrangements within Sestrin2 and CASTOR1 that trigger their dissociation from GATOR2. Binding of either sensor restricts the dynamic WDR24 β-propeller of GATOR2, a domain essential for nutrient-dependent mTORC1 activation. These findings reveal the allosteric mechanisms that convey amino acid sufficiency to GATOR2 and the ensuing structural changes that lead to mTORC1 activation.
Cryoelectron microscopy, Nutrient signalling, TOR signalling
mAChR4 suppresses liver disease via GAP-induced antimicrobial immunity
Original Paper | Alcoholic liver disease | 2025-08-19 20:00 EDT
Cristina Llorente, Fernanda Raya Tonetti, Ryan Bruellman, Rocío Brea, Nuria Pell, Phillipp Hartmann, Luca Maccioni, Hui Han, Noemí Cabré, Junlai Liu, Alvaro Eguileor, Marcos F. Fondevila, Abraham S. Meijnikman, Cynthia L. Hsu, Ameera Alghafri, Rongrong Zhou, Bei Gao, Yi Duan, Peng Zhang, Mark A. Febbraio, Koji Taniguchi, Rodney D. Newberry, Derrick E. Fouts, David A. Brenner, Peter Stärkel, Michael Karin, Bernd Schnabl
Alcohol-use disorder and alcohol-associated liver disease (ALD) are major causes of death and liver transplantation1. The gut-liver axis has a crucial yet poorly understood role in ALD pathogenesis, which depends on microbial translocation. Intestinal goblet cells (GCs) educate the immune system by forming GC-associated antigen passages (GAPs) on activation of muscarinic acetylcholine receptor M4 (mAChR4, also known as M4), enabling sampling of luminal antigens by lamina propria antigen-presenting cells. Here we show that chronic alcohol use in humans and mice downregulates small intestinal mAChR4 and reduces GAP formation, disrupting antimicrobial immunity. This is reversed on activation of intestinal IL-6 signal transducer (IL6ST, also known as glycoprotein 130; gp130), which restores mAChR4 expression and GAP formation, enabling induction of downstream type-3 innate lymphoid cell-derived IL-22 and antimicrobial REG3 proteins. This blunts translocation of enteric bacteria to the liver, thereby conferring ALD resistance. GAP induction by GC-specific mAChR4 activation was essential and sufficient for prevention of ethanol-induced steatohepatitis. These results lay the foundation for a therapeutic approach using mAChR4 or IL6ST agonists to promote GAP formation and prevent ALD by inhibiting microbial translocation.
Alcoholic liver disease, Antimicrobial responses, Antimicrobials, Molecular biology, Mucosal immunology
Molecular mechanism of ultrafast transport by plasma membrane Ca2+-ATPases
Original Paper | Cryoelectron microscopy | 2025-08-19 20:00 EDT
Deivanayagabarathy Vinayagam, Oleg Sitsel, Uwe Schulte, Cristina E. Constantin, Wout Oosterheert, Daniel Prumbaum, Gerd Zolles, Bernd Fakler, Stefan Raunser
Tight control of intracellular Ca2+ levels is fundamental as they are used to control numerous signal transduction pathways1. Plasma membrane Ca2+-ATPases (PMCAs) have a crucial role in this process by extruding Ca2+ against a steep concentration gradient from the cytosol to the extracellular space2. Although new details of PMCA biology are constantly being uncovered, the structural basis of the most distinguishing features of these pumps, namely, transport rates in the kilohertz range and regulation of activity by the plasma membrane phospholipid PtdIns(4,5)P2, has so far remained elusive. Here we present the structures of mouse PMCA2 in the presence and absence of its accessory subunit neuroplastin in eight different stages of its transport cycle. Combined with whole-cell recordings that accurately track PMCA-mediated Ca2+ extrusion in intact cells, these structures enable us to establish the first comprehensive transport model for a PMCA, reveal the role of disease-causing mutations and uncover the structural underpinnings of regulatory PMCA-phospholipid interaction. The transport cycle-dependent dynamics of PtdIns(4,5)P2 are fundamental for its role as a ‘latch’ promoting the fast release of Ca2+ and opening a passageway for counter-ions. These actions are required for maintaining the ultra-fast transport cycle. Moreover, we identify the PtdIns(4,5)P2-binding site as an unanticipated target for drug-mediated manipulation of intracellular Ca2+ levels. Our work provides detailed structural insights into the uniquely fast operation of native PMCA-type Ca2+ pumps and its control by membrane lipids and drugs.
Cryoelectron microscopy, Membrane proteins
Proximity screening greatly enhances electronic quality of graphene
Original Paper | Electronic properties and devices | 2025-08-19 20:00 EDT
Daniil Domaretskiy, Zefei Wu, Van Huy Nguyen, Ned Hayward, Ian Babich, Xiao Li, Ekaterina Nguyen, Julien Barrier, Kornelia Indykiewicz, Wendong Wang, Roman V. Gorbachev, Na Xin, Kenji Watanabe, Takashi Taniguchi, Lee Hague, Vladimir I. Fal’ko, Irina V. Grigorieva, Leonid A. Ponomarenko, Alexey I. Berdyugin, Andre K. Geim
The electronic quality of two-dimensional systems is crucial when exploring quantum transport phenomena. In semiconductor heterostructures, decades of optimization have yielded record-quality two-dimensional gases with transport and quantum mobilities reaching close to 108 and 106 cm2 V-1 s-1, respectively1,2,3,4,5,6,7,8,9,10. Although the quality of graphene devices has also been improving, it remains comparatively lower11,12,13,14,15,16,17. Here we report a transformative improvement in the electronic quality of graphene by employing graphite gates placed in its immediate proximity, at 1 nm separation. The resulting screening reduces charge inhomogeneity by two orders of magnitude, bringing it down to a few 107 cm-2 and limiting potential fluctuations to less than 1 meV. Quantum mobilities reach 107 cm2 V-1 s-1, surpassing those in the highest-quality semiconductor heterostructures by an order of magnitude, and the transport mobilities match their record9,10. This quality enables Shubnikov-de Haas oscillations in fields as low as 1 mT and quantum Hall plateaux below 5 mT. Although proximity screening predictably suppresses electron-electron interactions, fractional quantum Hall states remain observable with their energy gaps reduced only by a factor of 3-5 compared with unscreened devices, demonstrating that many-body phenomena at spatial scales shorter than 10 nm remain robust. Our results offer a reliable route to improving electronic quality in graphene and other two-dimensional systems, which should facilitate the exploration of new physics previously obscured by disorder.
Electronic properties and devices, Electronic properties and materials
TCF1 and LEF1 promote B-1a cell homeostasis and regulatory function
Original Paper | Cell biology | 2025-08-19 20:00 EDT
Qian Shen, Hao Wang, Jonathan A. Roco, Xiangpeng Meng, Marita Bosticardo, Marie Hodges, Michael Battaglia, Zhi-Ping Feng, Benjamin James Talks, Jason Powell, Vijaya Baskar Mahalingam Shanmugiah, Julia Chu, Najib M. Rahman, Alguili Elsheikh, Probir Chakravarty, Amalie Grenov, Max Emmerich, Ottavia M. Delmonte, Alexandra F. Freeman, Michael D. Keller, Brahim Belaid, Ilenia Papa, James C. Lee, Pablo F. Cañete, Paula Gonzalez-Figueroa, Yaoyuan Zhang, Hai-Hui Xue, Samra Turajlic, Luigi D. Notarangelo, Muzlifah Haniffa, Lee Ann Garrett-Sinha, Helen M. Parry, Nikolaos I. Kanellakis, Carola G. Vinuesa
B-1 cells are innate-like immune cells abundant in serosal cavities with antibodies enriched in bacterial recognition, yet their existence in humans has been controversial1,2,3. The CD5+ B-1a subset expresses anti-inflammatory molecules including IL-10, PDL1 and CTLA4 and can be immunoregulatory4,5,6. Unlike conventional B cells that are continuously replenished, B-1a cells are produced early in life and maintained through self-renewal7. Here we show that the transcription factors TCF1 and LEF1 are critical regulators of B-1a cells. LEF1 expression is highest in fetal and bone marrow B-1 progenitors, whereas the levels of TCF1 are higher in splenic and peritoneal B-1 cells than in B-1 progenitors. TCF1-LEF1 double deficient mice have reduced B-1a cells and defective B-1a cell maintenance. These transcription factors promote MYC-dependent metabolic pathways and induce a stem-like population upon activation, partly via IL-10 production. In the absence of TCF1 and LEF1, B-1 cells proliferate excessively and acquire an exhausted phenotype with reduced IL-10 and PDL1 expression. Furthermore, adoptive transfer of B-1 cells lacking TCF1 and LEF1 fails to suppress brain inflammation. These transcription factors are also expressed in human chronic lymphocytic leukaemia B cells and in a B-1-like population that is abundant in pleural fluid and circulation of some patients with pleural infection. Our findings define a TCF1-LEF1-driven transcriptional program that integrates stemness and regulatory function in B-1a cells.
Cell biology, Inflammation
Experimental determination of partial charges with electron diffraction
Original Paper | Analytical chemistry | 2025-08-19 20:00 EDT
Soheil Mahmoudi, Tim Gruene, Christian Schröder, Khalil D. Ferjaoui, Erik Fröjdh, Aldo Mozzanica, Kiyofumi Takaba, Anatoliy Volkov, Julian Maisriml, Vladimir Paunović, Jeroen A. van Bokhoven, Bernhard K. Keppler
Atomic partial charges, integral to understanding molecular structure, interactions and reactivity, remain an ambiguous concept lacking a precise quantum-mechanical definition1,2. The accurate determination of atomic particle charges has far-reaching implications in fields such as chemical synthesis, applied materials science and theoretical chemistry, to name a few3. They play essential parts in molecular dynamics simulations, which can act as a computational microscope for chemical processes4. Until now, no general experimental method has quantified the partial charges of individual atoms in a chemical compound. Here we introduce an experimental method that assigns partial charges based on crystal structure determination through electron diffraction, applicable to any crystalline compound. Seamlessly integrated into standard electron crystallography workflows, this approach requires no specialized software or advanced expertise. Furthermore, it is not limited to specific classes of compounds. The versatility of this method is demonstrated by its application to a wide array of compounds, including the antibiotic ciprofloxacin, the amino acids histidine and tyrosine, and the inorganic zeolite ZSM-5. We refer to this new concept as ionic scattering factors modelling. It fosters a more comprehensive and precise understanding of molecular structures, providing opportunities for applications across numerous fields in the chemical and materials sciences.
Analytical chemistry, Characterization and analytical techniques, Computational chemistry, Structural materials, Structure elucidation
Targeting G1-S-checkpoint-compromised cancers with cyclin A/B RxL inhibitors
Original Paper | Mitosis | 2025-08-19 20:00 EDT
Shilpa Singh, Catherine E. Gleason, Min Fang, Yasmin N. Laimon, Vishal Khivansara, Shanhai Xie, Yavuz T. Durmaz, Aniruddha Sarkar, Kenneth Ngo, Varunika Savla, Yixiang Li, Muhannad Abu-Remaileh, Xinyue Li, Marie-Anais Locquet, Bishma Tuladhar, Ranya Odeh, Frances Hamkins-Indik, Daphne He, Miles W. Membreno, Meisam Nosrati, Nathan N. Gushwa, Siegfried S. F. Leung, Breena Fraga-Walton, Luis Hernandez, Miguel P. Baldomero, Bryan M. Lent, David Spellmeyer, Joshua F. Luna, Dalena Hoang, Yuliana Gritsenko, Manesh Chand, Megan K. DeMart, Sammy Metobo, Chinmay Bhatt, Justin A. Shapiro, Kai Yang, Nathan J. Dupper, Andrew T. Bockus, Jinshu Fang, Ramesh Bambal, Peadar Cremin, John G. Doench, James B. Aggen, Li-Fen Liu, Bernard Levin, Evelyn W. Wang, Iolanda Vendrell, Roman Fischer, Benedikt Kessler, Prafulla C. Gokhale, Sabina Signoretti, Alexander Spektor, Constantine Kreatsoulas, Marie Evangelista, Rajinder Singh, David J. Earp, Deepak Nijhawan, Pablo D. Garcia, Matthew G. Oser
Small-cell lung cancers (SCLCs) contain near-universal loss-of-function mutations in RB1 and TP53, compromising the G1-S checkpoint and leading to dysregulated E2F activity1. Other cancers similarly disrupt the G1-S checkpoint through loss of CDKN2A or amplification of cyclin D or cyclin E, also resulting in excessive E2F activity2,3. Although E2F activation is essential for cell cycle progression, hyperactivation promotes apoptosis4,5,6,7,8,9, presenting a therapeutic vulnerability. Cyclin proteins use a conserved hydrophobic patch to bind to substrates bearing short linear RxL motifs10,11,12,13. Cyclin A represses E2F through an RxL-dependent interaction10,14, which, when disrupted, hyperactivates E2F15. However, this substrate interface has remained difficult to target. Here we developed cell-permeable, orally bioavailable macrocyclic peptides that inhibit RxL-mediated interactions of cyclins with their substrates. Dual inhibitors of cyclin A and cyclin B RxL motifs (cyclin A/Bi) selectively kill SCLC cells and other cancer cells with high E2F activity. Genetic screens revealed that cyclin A/Bi induces apoptosis through cyclin B- and CDK2-dependent spindle assembly checkpoint activation. Mechanistically, cyclin A/Bi hyperactivates E2F and cyclin B by blocking cyclin A-E2F and cyclin B-MYT1 RxL interactions. Notably, cyclin A/Bi promoted the formation of neomorphic cyclin B-CDK2 complexes, which drive spindle assembly checkpoint activation and mitotic cell death. Finally, orally administered cyclin A/Bi showed robust anti-tumour activity in chemotherapy-resistant SCLC patient-derived xenografts. These findings reveal gain-of-function mechanisms through which cyclin A/Bi triggers apoptosis and support their development for E2F-driven cancers.
Mitosis, Peptides, Target validation, Targeted therapies
Realization of a doped quantum antiferromagnet in a Rydberg tweezer array
Original Paper | Quantum simulation | 2025-08-19 20:00 EDT
Mu Qiao, Gabriel Emperauger, Cheng Chen, Lukas Homeier, Simon Hollerith, Guillaume Bornet, Romain Martin, Bastien Gély, Lukas Klein, Daniel Barredo, Sebastian Geier, Neng-Chun Chiu, Fabian Grusdt, Annabelle Bohrdt, Thierry Lahaye, Antoine Browaeys
Doping an antiferromagnetic (AFM) Mott insulator is central to our understanding of a variety of phenomena in strongly correlated electrons, including high-temperature superconductors1,2. To describe the competition between tunnelling t of hole dopants and AFM spin interactions J, theoretical and numerical studies often focus on the paradigmatic t-J model3 and the direct analogue quantum simulation of this model in the relevant regime of high-particle density has long been sought4,5. Here we realize a doped quantum antiferromagnet with next-nearest-neighbour (NNN) tunnellings t‘ (refs. 6,7,8,9,10) and hard-core bosonic holes11 using a Rydberg tweezer platform. We use coherent dynamics between three Rydberg levels, encoding spins and holes12, to implement a tunable bosonic t-J-V model allowing us to study previously inaccessible parameter regimes. We observe dynamical phase separation between hole and spin domains for |t/J| ≪ 1 and demonstrate the formation of repulsively bound hole pairs in a variety of spin backgrounds. The interference between NNN tunnellings t‘ and perturbative pair tunnelling gives rise to light and heavy pairs depending on the sign of t. Using the single-site control allows us to study the dynamics of a single hole in 2D square lattice (anti)ferromagnets. The model we implement extends the toolbox of Rydberg tweezer experiments beyond spin-1/2 models13 to a larger class of t-J and spin-1 models14,15.
Quantum simulation, Superconducting properties and materials
Electron flow matching for generative reaction mechanism prediction
Original Paper | Cheminformatics | 2025-08-19 20:00 EDT
Joonyoung F. Joung, Mun Hong Fong, Nicholas Casetti, Jordan P. Liles, Ne S. Dassanayake, Connor W. Coley
Central to our understanding of chemical reactivity is the principle of mass conservation1, which is fundamental for ensuring physical consistency, balancing equations and guiding reaction design. However, data-driven computational models2,3,4,5,6,7,8,9 for tasks such as reaction product prediction rarely abide by this most basic constraint10,11,12,13. Here we recast the problem of reaction prediction as a problem of electron redistribution using the modern deep generative framework of flow matching14,15,16, explicitly conserving both mass and electrons through the bond-electron (BE) matrix representation17,18. Our model, FlowER, overcomes limitations inherent in previous approaches by enforcing exact mass conservation, resolving hallucinatory failure modes, recovering mechanistic reaction sequences for unseen substrate scaffolds and generalizing effectively to out-of-domain reaction classes with extremely data-efficient fine-tuning. FlowER also enables downstream estimation of thermodynamic or kinetic feasibility and manifests a degree of chemical intuition in reaction prediction tasks. This inherently interpretable framework represents an important step in bridging the gap between predictive accuracy and mechanistic understanding in data-driven reaction outcome prediction.
Cheminformatics, Computer science, Reaction mechanisms
A fluorescent-protein spin qubit
Original Paper | Quantum metrology | 2025-08-19 20:00 EDT
Jacob S. Feder, Benjamin S. Soloway, Shreya Verma, Zhi Z. Geng, Shihao Wang, Bethel B. Kifle, Emmeline G. Riendeau, Yeghishe Tsaturyan, Leah R. Weiss, Mouzhe Xie, Jun Huang, Aaron Esser-Kahn, Laura Gagliardi, David D. Awschalom, Peter C. Maurer
Quantum bits (qubits) are two-level quantum systems that support initialization, readout and coherent control1. Optically addressable spin qubits form the foundation of an emerging generation of nanoscale sensors2,3,4,5,6,7. The engineering of these qubits has mainly focused on solid-state systems. However, fluorescent proteins, rather than exogenous fluorescent probes, have become the gold standard for in vivo microscopy because of their genetic encodability8,9. Although fluorescent proteins possess a metastable triplet state10, they have not been investigated as qubits. Here we realize an optically addressable spin qubit in enhanced yellow fluorescent protein. A near-infrared laser pulse enables triggered readout of the triplet state with up to 20% spin contrast. Using coherent microwave control of the enhanced-yellow-fluorescent-protein spin at liquid-nitrogen temperatures, we measure a (16 ± 2) μs coherence time under Carr-Purcell-Meiboom-Gill decoupling. We express the qubit in mammalian cells, maintaining contrast and coherent control despite the complex intracellular environment. Finally, we demonstrate optically detected magnetic resonance in bacterial cells at room temperature with contrast up to 8%. Our results introduce fluorescent proteins as a powerful qubit platform that paves the way for applications in the life sciences, such as nanoscale field sensing and spin-based imaging modalities.
Quantum metrology, Qubits
Electrochemical loading enhances deuterium fusion rates in a metal target
Original Paper | Electrocatalysis | 2025-08-19 20:00 EDT
Kuo-Yi Chen, Jannis Maiwald, Phil A. Schauer, Sergey Issinski, Fatima H. Garcia, Ryan Oldford, Luca Egoriti, Shota Higashino, Aref E. Vakili, Yunzhou Wen, Joseph Z. X. Koh, Thomas Schenkel, Monika Stolar, Amanda K. Brown, Curtis P. Berlinguette
Nuclear fusion research for energy applications aims to create conditions that release more energy than required to initiate the fusion process1. To generate meaningful amounts of energy, fuels such as deuterium need to be spatially confined to increase the collision probability of particles2,3,4. We therefore set out to investigate whether electrochemically loading a metal lattice with deuterium fuel could increase the probability of nuclear fusion events. Here we report a benchtop fusion reactor that enabled us to bombard a palladium metal target with deuterium ions. These deuterium ions undergo deuterium-deuterium fusion reactions within the palladium metal. We showed that the in situ electrochemical loading of deuterium into the palladium target resulted in a 15(2)% increase in deuterium-deuterium fusion rates. This experiment shows how the electrochemical loading of a metal target at the electronvolt energy scale can affect nuclear reactions at the megaelectronvolt energy scale.
Electrocatalysis, Nuclear fusion and fission
Thymic epithelial cells amplify epigenetic noise to promote immune tolerance
Original Paper | Epigenetics in immune cells | 2025-08-19 20:00 EDT
Noah Gamble, Jason A. Caldwell, Joshua McKeever, Caroline Kaiser, Alexandra Bradu, Peyton J. Dooley, Sandy Klemm, William J. Greenleaf, Narutoshi Hibino, Aaron R. Dinner, Andrew S. Koh
Cellular plasticity is a principal feature of vertebrate adaptation, tissue repair and tumorigenesis1,2. However, the mechanisms that regulate the stability of somatic cell fates remain unclear. Here, we use the somatic plasticity of thymic epithelial cells, which facilitates the selection of a self-discriminating T cell repertoire3, as a physiological model system to show that fluctuations in background chromatin accessibility in nucleosome-dense regions are amplified during thymic epithelial maturation for the ectopic expression of genes restricted to other specialized cell types. This chromatin destabilization was not dependent on AIRE-induced transcription but was preceded by repression of the tumour suppressor p53. Augmenting p53 activity indirectly stabilized chromatin, inhibited ectopic transcription, limited cellular plasticity and caused multi-organ autoimmunity. Genomic regions with heightened chromatin accessibility noise were selectively enriched for nucleosome-destabilizing polymeric AT tracts and were associated with elevated baseline DNA damage and transcriptional initiation. Taken together, our findings define molecular levers that modulate cell fate integrity and are used by thymic epithelial cells for immunological tolerance.
Epigenetics in immune cells, Epigenomics
Emerging evidence of abrupt changes in the Antarctic environment
Review Paper | Climate-change impacts | 2025-08-19 20:00 EDT
Nerilie J. Abram, Ariaan Purich, Matthew H. England, Felicity S. McCormack, Jan M. Strugnell, Dana M. Bergstrom, Tessa R. Vance, Tobias Stål, Barbara Wienecke, Petra Heil, Edward W. Doddridge, Jean-Baptiste Sallée, Thomas J. Williams, Anya M. Reading, Andrew Mackintosh, Ronja Reese, Ricarda Winkelmann, Ann Kristin Klose, Philip W. Boyd, Steven L. Chown, Sharon A. Robinson
Human-caused climate change worsens with every increment of additional warming, although some impacts can develop abruptly. The potential for abrupt changes is far less understood in the Antarctic compared with the Arctic, but evidence is emerging for rapid, interacting and sometimes self-perpetuating changes in the Antarctic environment. A regime shift has reduced Antarctic sea-ice extent far below its natural variability of past centuries, and in some respects is more abrupt, non-linear and potentially irreversible than Arctic sea-ice loss. A marked slowdown in Antarctic Overturning Circulation is expected to intensify this century and may be faster than the anticipated Atlantic Meridional Overturning Circulation slowdown. The tipping point for unstoppable ice loss from the West Antarctic Ice Sheet could be exceeded even under best-case CO2 emission reduction pathways, potentially initiating global tipping cascades. Regime shifts are occurring in Antarctic and Southern Ocean biological systems through habitat transformation or exceedance of physiological thresholds, and compounding breeding failures are increasing extinction risk. Amplifying feedbacks are common between these abrupt changes in the Antarctic environment, and stabilizing Earth’s climate with minimal overshoot of 1.5 °C will be imperative alongside global adaptation measures to minimise and prepare for the far-reaching impacts of Antarctic and Southern Ocean abrupt changes.
Climate-change impacts, Cryospheric science, Environmental impact
Engineered yeast provides rare but essential pollen sterols for honeybees
Original Paper | Agroecology | 2025-08-19 20:00 EDT
Elynor Moore, Raquel T. de Sousa, Stella Felsinger, Jonathan A. Arnesen, Jane D. Dyekjær, Dudley I. Farman, Rui F. S. Gonçalves, Philip C. Stevenson, Irina Borodina, Geraldine A. Wright
Honeybees are important crop pollinators, but they increasingly face pollen starvation as a result of agricultural intensification and climate change1. Frequent flowering dearth periods and high-density rearing conditions weaken colonies, which often leads to their demise2. Beekeepers provide colonies with pollen substitutes, but these feeds do not sustain brood production because they lack essential sterols found in pollen3,4. Here we describe a technological advance in honeybee nutrition with wide-reaching impacts on global food security. We first measured the quantity and proportion of sterols present in honeybee tissues. Using this information, we genetically engineered a strain of the oleaginous yeast Yarrowia lipolytica to produce a mixture of essential sterols for bees and incorporated this yeast strain into an otherwise nutritionally complete diet. Colonies exclusively fed with this diet reared brood for significantly longer than those fed diets without suitable sterols. The use of this method to incorporate sterol supplements into pollen substitutes will enable honeybee colonies to produce brood in the absence of floral pollen. Optimized diets created using this yeast strain could also reduce competition between bee species for access to natural floral resources and stem the decline in wild bee populations.
Agroecology, Entomology, Metabolic engineering
Extremely stripped supernova reveals a silicon and sulfur formation site
Original Paper | Time-domain astronomy | 2025-08-19 20:00 EDT
Steve Schulze, Avishay Gal-Yam, Luc Dessart, Adam A. Miller, Stan E. Woosley, Yi Yang, Mattia Bulla, Ofer Yaron, Jesper Sollerman, Alexei V. Filippenko, K-Ryan Hinds, Daniel A. Perley, Daichi Tsuna, Ragnhild Lunnan, Nikhil Sarin, Seán J. Brennan, Thomas G. Brink, Rachel J. Bruch, Ping Chen, Kaustav K. Das, Suhail Dhawan, Claes Fransson, Christoffer Fremling, Anjasha Gangopadhyay, Ido Irani, Anders Jerkstrand, Nikola Knežević, Doron Kushnir, Keiichi Maeda, Kate Maguire, Eran Ofek, Conor M. B. Omand, Yu-Jing Qin, Yashvi Sharma, Tawny Sit, Gokul P. Srinivasaragavan, Nora L. Strothjohann, Yuki Takei, Eli Waxman, Lin Yan, Yuhan Yao, WeiKang Zheng, Erez A. Zimmerman, Eric C. Bellm, Michael W. Coughlin, Frank J. Masci, Josiah Purdum, Mickaël Rigault, Avery Wold, Shrinivas R. Kulkarni
Stars are initially powered by the fusion of hydrogen to helium. These ashes serve as fuel in a series of stages1,2,3, transforming massive stars into a structure of shells. These are composed of natal hydrogen on the outside and consecutively heavier compositions inside, predicted to be dominated by He, C/O, O/Ne/Mg and O/Si/S (refs. 4,5). Silicon and sulfur are fused into iron, leading to the collapse of the core and either a supernova explosion or the formation of a black hole6,7,8,9. Stripped stars, in which the outer hydrogen layer has been removed and the internal He-rich or even the C/O layer below it is exposed10, provide evidence for this shell structure and the cosmic element production mechanism it reflects. The supernova types that arise from stripped stars embedded in shells of circumstellar material (CSM) confirm this scenario11,12,13,14,15. However, direct evidence for the most interior shells, which are responsible for producing elements heavier than oxygen, is lacking. Here we report the discovery of the supernova (SN) 2021yfj resulting from a star stripped to its O/Si/S-rich layer. We directly observe a thick, massive Si/S-rich shell, expelled by the progenitor shortly before the supernova explosion. Exposing such an inner stellar layer is theoretically challenging and probably requires a rarely observed mass-loss mechanism. This rare supernova event reveals advanced stages of stellar evolution, forming heavier elements, including silicon, sulfur and argon, than those detected on the surface of any known class of massive stars.
Time-domain astronomy, Transient astrophysical phenomena
Atomic dynamics of gas-dependent oxide reducibility
Original Paper | Chemical engineering | 2025-08-19 20:00 EDT
Xiaobo Chen, Jianyu Wang, Shyam Bharatkumar Patel, Shuonan Ye, Yupeng Wu, Zhikang Zhou, Linna Qiao, Yuxi Wang, Nebojsa Marinkovic, Meng Li, Sooyeon Hwang, Dmitri N. Zakharov, Lu Ma, Qin Wu, Jorge Anibal Boscoboinik, Judith C. Yang, Guangwen Zhou
Understanding oxide reduction is critical for advancing metal production1,2, catalysis3,4 and energy technologies5. Although carbon monoxide (CO) and hydrogen (H2) are widely used reductants, the mechanisms by which they work are often presumed to be similar, both involving lattice oxygen removal6,7,8,9. However, because of growing interest in replacing CO with H2 to lower CO2 emissions, distinguishing gas-specific reduction pathways is critical. Yet, capturing these atomic-scale processes under reactive gas and high-temperature conditions remains challenging. Here we use environmental transmission electron microscopy, which is capable of real-time, atomic-resolution imaging of gas-solid redox reactions10,11,12,13,14,15,16, to directly visualize the gas-dependent oxide reduction dynamics in NiO. We show that CO drives surface nucleation and the growth of metallic Ni islands, leading to self-limiting surface metallization. Conversely, H2 activates a coupled surface-to-bulk transformation, where protons from dissociated H2 infiltrate the oxide lattice to promote the inward migration of surface-generated oxygen vacancies and enabling bulk metallization. By contrast, oxygen vacancies formed by CO remain confined near the surface, where they rapidly form a metallic Ni layer that inhibits further reduction. These results reveal distinct atomistic pathways for CO and H2 and provide insights that may guide metallurgical processes and catalyst design.
Chemical engineering, Corrosion, Reaction kinetics and dynamics, Synthesis and processing
Cancer-induced nerve injury promotes resistance to anti-PD-1 therapy
Original Paper | Cancer microenvironment | 2025-08-19 20:00 EDT
Erez N. Baruch, Frederico O. Gleber-Netto, Priyadharsini Nagarajan, Xiayu Rao, Shamima Akhter, Tuany Eichwald, Tongxin Xie, Mohammad Balood, Adebayo Adewale, Shorook Naara, Hinduja N. Sathishkumar, Shajedul Islam, William McCarthy, Brandi J. Mattson, Renata Ferrarotto, Michael K. Wong, Michael A. Davies, Sonali Jindal, Sreyashi Basu, Karine Roversi, Amin Reza Nikpoor, Maryam Ahmadi, Ali Ahmadi, Catherine Harwood, Irene Leigh, Dennis Gong, Paulino Tallón de Lara, Derrick L. Tao, Tara M. Davidson, Nadim J. Ajami, Andrew Futreal, Kunal Rai, Veena Kochat, Micah Castillo, Preethi Gunaratne, Ryan P. Goepfert, Sharia D. Hernandez, Nikhil I. Khushalani, Jing Wang, Stephanie S. Watowich, George A. Calin, Michael R. Migden, Mona Yuan, Naijiang Liu, Yi Ye, William L. Hwang, Paola D. Vermeer, Nisha J. D’Silva, Yuri L. Bunimovich, Dan Yaniv, Jared K. Burks, Javier Gomez, Patrick M. Dougherty, Kenneth Y. Tsai, James P. Allison, Padmanee Sharma, Jennifer A. Wargo, Jeffrey N. Myers, Sebastien Talbot, Neil D. Gross, Moran Amit
Perineural invasion (PNI) is a well-established factor of poor prognosis in multiple cancer types1, yet its mechanism remains unclear. Here we provide clinical and mechanistic insights into the role of PNI and cancer-induced nerve injury (CINI) in resistance to anti-PD-1 therapy. Our study demonstrates that PNI and CINI of tumour-associated nerves are associated with poor response to anti-PD-1 therapy among patients with cutaneous squamous cell carcinoma, melanoma and gastric cancer. Electron microscopy and electrical conduction analyses reveal that cancer cells degrade the nerve fibre myelin sheets. The injured neurons respond by autonomously initiating IL-6- and type I interferon-mediated inflammation to promote nerve healing and regeneration. As the tumour grows, the CINI burden increases, and its associated inflammation becomes chronic and skews the general immune tone within the tumour microenvironment into a suppressive and exhaustive state. The CINI-driven anti-PD-1 resistance can be reversed by targeting multiple steps in the CINI signalling process: denervating the tumour, conditional knockout of the transcription factor mediating the injury signal within neurons (Atf3), knockout of interferon-α receptor signalling (Ifnar1-/-) or by combining anti-PD-1 and anti-IL-6-receptor blockade. Our findings demonstrate the direct immunoregulatory roles of CINI and its therapeutic potential.
Cancer microenvironment, Immunotherapy, Neuroimmunology, Squamous cell carcinoma, Tumour immunology
A novel bacterial protein family that catalyses nitrous oxide reduction
Original Paper | Environmental impact | 2025-08-19 20:00 EDT
Guang He, Weijiao Wang, Gao Chen, Yongchao Xie, Jerry M. Parks, Megan E. Davin, Robert L. Hettich, Konstantinos T. Konstantinidis, Frank E. Löffler
Nitrous oxide (N2O), a driver of global warming and climate change, has reached unprecedented concentrations in Earth’s atmosphere1. Current N2O sources outpace N2O sinks, emphasizing the need for comprehensive understanding of processes that consume N2O. Microbes that express the enzyme N2O reductase (N2OR) convert N2O to climate change-neutral dinitrogen (N2). Known N2ORs belong to the canonical clade I and clade II NosZ reductases and are considered key enzymes for N2O reduction2,3,4. Here we report a previously unrecognized protein family with a role in N2O reduction, clade III lactonase-type N2OR (L-N2OR), which diverges in sequence from canonical NosZ but conserves three-dimensional protein structural features. Integrated physiological, metagenomic, proteomic and structural modelling studies demonstrate that L-N2ORs catalyse N2O reduction. L-N2OR genes occur in several phyla, predominantly in uncultured taxa with broad geographic distribution. Our findings expand the known diversity of N2ORs and implicate previously unrecognized taxa (for example, Nitrospinota) in N2O consumption. The expansion of N2OR diversity and the identification of a novel type of catalyst for N2O reduction advances the understanding of N2O sinks, has implications for greenhouse gas emission and climate change modelling, and expands opportunities for innovative biotechnologies aimed at curbing N2O emissions5,6.
Environmental impact, Soil microbiology
SLC45A4 is a pain gene encoding a neuronal polyamine transporter
Original Paper | Chronic pain | 2025-08-19 20:00 EDT
Steven J. Middleton, Sigurbjörn Markússon, Mikael Åkerlund, Justin C. Deme, Mandy Tseng, Wenqianglong Li, Sana R. Zuberi, Gabriel Kuteyi, Peter Sarkies, Georgios Baskozos, Jimena Perez-Sanchez, Adham Farah, Harry L. Hébert, Sylvanus Toikumo, Zhanru Yu, Susan Maxwell, Yin Y. Dong, Benedikt M. Kessler, Henry R. Kranzler, John E. Linley, Blair H. Smith, Susan M. Lea, Joanne L. Parker, Valeriya Lyssenko, Simon Newstead, David L. Bennett
Polyamines are regulatory metabolites with key roles in transcription, translation, cell signalling and autophagy1. They are implicated in multiple neurological disorders, including stroke, epilepsy and neurodegeneration, and can regulate neuronal excitability through interactions with ion channels2. Polyamines have been linked to pain, showing altered levels in human persistent pain states and modulation of pain behaviour in animal models3. However, the systems governing polyamine transport within the nervous system remain unclear. Here, undertaking a genome-wide association study (GWAS) of chronic pain intensity in the UK Biobank (UKB), we found a significant association between pain intensity and variants mapping to the SLC45A4 gene locus. In the mouse nervous system, Slc45a4 expression is enriched in all sensory neuron subtypes within the dorsal root ganglion, including nociceptors. Cell-based assays show that SLC45A4 is a selective plasma membrane polyamine transporter, and the cryo-electron microscopy (cryo-EM) structure reveals a regulatory domain and basis for polyamine recognition. Mice lacking SLC45A4 show normal mechanosensitivity but reduced sensitivity to noxious heat- and algogen-induced tonic pain that is associated with reduced excitability of C-polymodal nociceptors. Our findings therefore establish a role for neuronal polyamine transport in pain perception and identify a target for therapeutic intervention in pain treatment.
Chronic pain, Cryoelectron microscopy, Genome-wide association studies, Transporters in the nervous system
A missing enzyme-rescue metabolite as cause of a rare skeletal dysplasia
Original Paper | Deoxy sugars | 2025-08-19 20:00 EDT
Jean Jacobs, Hristiana Lyubenova, Sven Potelle, Johannes Kopp, Isabelle Gerin, Wing Lee Chan, Miguel Rodriguez de los Santos, Wiebke Hülsemann, Martin A. Mensah, Valérie Cormier-Daire, Marieke Joosten, Hennie T. Bruggenwirth, Kyra E. Stuurman, Valancy Miranda, Philippe M. Campeau, Lars Wittler, Julie Graff, Stefan Mundlos, Daniel M. Ibrahim, Emile Van Schaftingen, Björn Fischer-Zirnsak, Uwe Kornak, Nadja Ehmke, Guido T. Bommer
Living cells depend on an intricate network of chemical reactions catalysed by enzymes, which sometimes make mistakes that lead to their inactivation. Here we report a metabolite-based mechanism for preserving enzyme function in an unfavourable environment. We found that the enzyme TGDS produces UDP-4-keto-6-deoxyglucose, a mimic of the reaction intermediate of the enzyme UXS1, which regenerates the essential cofactor NAD+ within the catalytic pocket of UXS1 by completing its catalytic cycle. Thus, the production of an ‘enzyme-rescue metabolite’ by TGDS represents a mechanism for maintaining the activity of an enzyme in a subcellular compartment where NAD+ is scarce. Using a combination of in vitro and in vivo studies, we demonstrate that the inability to produce sufficient amounts of this enzyme-rescue metabolite leads to the inactivation of UXS1, impairing the synthesis of specific glycans that are crucial for skeletal development. This provides an explanation for the development of the hereditary skeletal disorder Catel-Manzke syndrome in individuals with TGDS deficiency. Defects in similar protective layers might contribute to metabolic changes in other diseases that cannot be explained with common concepts in metabolic biochemistry.
Deoxy sugars, Disease genetics, Enzymes, Experimental models of disease, Glycobiology
Quantitative imaging of lipid transport in mammalian cells
Original Paper | Chemical tools | 2025-08-19 20:00 EDT
Juan M. Iglesias-Artola, Kristin Böhlig, Kai Schuhmann, Katelyn C. Cook, H. Mathilda Lennartz, Milena Schuhmacher, Pavel Barahtjan, Cristina Jiménez López, Radek Šachl, Vannuruswamy Garikapati, Karina Pombo-Garcia, Annett Lohmann, Petra Riegerová, Martin Hof, Björn Drobot, Andrej Shevchenko, Alf Honigmann, André Nadler
Eukaryotic cells produce over 1,000 different lipid species that tune organelle membrane properties, control signalling and store energy1,2. How lipid species are selectively sorted between organelles to maintain specific membrane identities is largely unclear, owing to the difficulty of imaging lipid transport in cells3. Here we measured the retrograde transport and metabolism of individual lipid species in mammalian cells using time-resolved fluorescence imaging of bifunctional lipid probes in combination with ultra-high-resolution mass spectrometry and mathematical modelling. Quantification of lipid flux between organelles revealed that directional, non-vesicular lipid transport is responsible for fast, species-selective lipid sorting, in contrast to the slow, unspecific vesicular membrane trafficking. Using genetic perturbations, we found that coupling between energy-dependent lipid flipping and non-vesicular transport is a mechanism for directional lipid transport. Comparison of metabolic conversion and transport rates showed that non-vesicular transport dominates the organelle distribution of lipids, while species-specific phospholipid metabolism controls neutral lipid accumulation. Our results provide the first quantitative map of retrograde lipid flux in cells4. We anticipate that our pipeline for mapping of lipid flux through physical and chemical space in cells will boost our understanding of lipids in cell biology and disease.
Chemical tools, Membrane lipids, Membrane trafficking
Discovery of a widespread chemical signalling pathway in the Bacteroidota
Original Paper | Bacteria | 2025-08-19 20:00 EDT
Luis Linares-Otoya, Jaden D. Shirkey, Bhuwan Khatri Chhetri, Amira Mira, Abhishek Biswas, Samuel L. Neff, Maria V. Linares-Otoya, Ye Chen, Julio V. Campos-Florian, Mayar L. Ganoza-Yupanqui, Philip D. Jeffrey, Frederick M. Hughson, Mohamed S. Donia
Considerable advances have been made in characterizing bioactive molecules secreted by bacteria, yet the regulatory elements controlling their production remain largely understudied. Here we identify and characterize the N-acyl-cyclolysine (ACL) system–a cell-density-dependent chemical signalling system specific to and widespread in the phylum Bacteroidota (formerly Bacteroidetes)–and show that it regulates the expression of co-localized operons encoding diverse secreted molecules. Using genetic and biochemical analyses, combined with structural studies of a key biosynthetic enzyme, AclA, we elucidate the molecular structure of various ACLs and their complete biosynthetic pathway involving l-lysine acylation and ATP-dependent cyclization. Furthermore, we find that secreted ACLs are sensed by a dedicated transcription factor, AclR, resulting in the expression of associated operons and the autoinduction of ACL biosynthesis. Moreover, we show that different Bacteroidota strains produce structurally diverse ACLs and encode transcription factors with varying ligand specificities. Finally, we find that the acl circuit is widely distributed and transcribed in human gut and oral microbiome samples, with clear evidence for an active role in regulating associated operons under host colonization conditions. Understanding the function of the ACL system in different contexts has the potential to reveal details about the biology, ecology and chemistry of the Bacteroidota and how members of this phylum interact with their environments and hosts.
Bacteria, Microbiome, Small molecules, X-ray crystallography
Flat-panel laser displays through large-scale photonic integrated circuits
Original Paper | Displays | 2025-08-19 20:00 EDT
Zhujun Shi, Risheng Cheng, Guohua Wei, Steven A. Hickman, Min Chul Shin, Peter Topalian, Lei Wang, Dusan Coso, Youmin Wang, Qingjun Wang, Brian Le, Lizzy Lee, Daniel Lopez, Yuhang Wu, Sean Braxton, Alexander Koshelev, Maxwell F. Parsons, Rahul Agarwal, Barry Silverstein, Yun Wang, Giuseppe Calafiore
Laser-based displays are highly sought after for their superior brightness and colour performance1, especially in advanced applications such as augmented reality (AR)2. However, their broader use has been hindered by bulky projector designs and complex optical module assemblies3. Here we introduce a laser display architecture enabled by large-scale visible photonic integrated circuits (PICs)4,5,6,7 to address these challenges. Unlike previous projector-style laser displays, this architecture features an ultra-thin, flat-panel form factor, replacing bulky free-space illumination modules with a single, high-performance photonic chip. Centimetre-scale PIC devices, which integrate thousands of distinct optical components on-chip, are carefully tailored to achieve high display uniformity, contrast and efficiency. We demonstrate a 2-mm-thick flat-panel laser display combining the PIC with a liquid-crystal-on-silicon (LCoS) panel8,9, achieving 211% of the colour gamut and more than 80% volume reduction compared with traditional LCoS displays. We further showcase its application in a see-through AR system. Our work represents an advancement in the integration of nanophotonics with display technologies, enabling a range of new display concepts, from high-performance immersive displays to slim-panel 3D holography.
Displays, Electrical and electronic engineering, Integrated optics, Silicon photonics
Network synchrony creates neural filters promoting quiescence in Drosophila
Original Paper | Circadian rhythms and sleep | 2025-08-19 20:00 EDT
Davide Raccuglia, Raquel Suárez-Grimalt, Laura Krumm, Anatoli Ender, Cédric B. Brodersen, Sridhar R. Jagannathan, Martin Freire Krück, Niccolò P. Pampaloni, Carolin Rauch, York Winter, Genevieve Yvon-Durocher, Richard Kempter, Jörg R. P. Geiger, David Owald
Animals require undisturbed periods of rest during which they undergo recuperative processes1. However, it is unclear how brain states arise that are able to dissociate an animal from its external world, enabling quiescent behaviours, while retaining vigilance to salient sensory cues2. Here we describe a neural mechanism in Drosophila that creates neural filters that engender a brain state that enables quiescent behaviour by generating coherent slow-wave activity (SWA)3 between sleep-need4 (R5)- and locomotion-promoting neural networks5. The coherence of SWA is subject to circadian and homeostatic control and can be modulated by sensory experience. Mimicry of coherent SWA reveals that R5 oscillations reduce responsiveness to visual stimuli by rhythmically associating neural activity of locomotion-promoting cells, effectively overruling their output. These networks can regulate behavioural responsiveness by providing antagonistic inputs to downstream head-direction cells6,7. Thus, coherent oscillations provide the mechanistic basis for a neural filter by temporally associating opposing signals, resulting in reduced functional connectivity between locomotion-gating and navigational networks. We propose that the temporal pattern of SWA provides the structure to create a ‘breakable’ filter, permitting the animal to enter a quiescent state, while providing the architecture for strong or salient stimuli to ‘break’ the neural interaction, consequently allowing the animal to react.
Circadian rhythms and sleep, Neurophysiology, Sensory processing
Axonal injury is a targetable driver of glioblastoma progression
Original Paper | Cancer in the nervous system | 2025-08-19 20:00 EDT
Melanie Clements, Wenhao Tang, Zan Florjanic Baronik, Holly Simpson Ragdale, Roger Oria, Dimitrios Volteras, Ian J. White, Gordon Beattie, Imran Uddin, Tchern Lenn, Rachel Lindsay, Sara Castro Devesa, Saketh R. Karamched, Mark F. Lythgoe, Vahid Shahrezaei, Valerie M. Weaver, Ryoichi Sugisawa, Federico Roncaroli, Samuel Marguerat, Ciaran S. Hill, Simona Parrinello
Glioblastoma (GBM) is an aggressive and highly therapy-resistant brain tumour1,2. Although advanced disease has been intensely investigated, the mechanisms that underpin the earlier, likely more tractable, stages of GBM development remain poorly understood. Here we identify axonal injury as a key driver of GBM progression, which we find is induced in white matter by early tumour cells preferentially expanding in this region. Mechanistically, axonal injury promotes gliomagenesis by triggering Wallerian degeneration, a targetable active programme of axonal death3, which we show increases neuroinflammation and tumour proliferation. Inactivation of SARM1, the key enzyme activated in response to injury that mediates Wallerian degeneration4, was sufficient to break this tumour-promoting feedforward loop, leading to the development of less advanced terminal tumours and prolonged survival in mice. Thus, targeting the tumour-induced injury microenvironment may supress progression from latent to advanced disease, thereby providing a potential strategy for GBM interception and control.
Cancer in the nervous system, CNS cancer
Nature Nanotechnology
Enhancing spectroscopy and microscopy with emerging methods in photon correlation and quantum illumination
Review Paper | Fluorescence spectroscopy | 2025-08-19 20:00 EDT
Chieh Tsao, Haonan Ling, Alex Hinkle, Yifan Chen, Keshav Kumar Jha, Zhen-Li Yan, Hendrik Utzat
Quantum optics has led to important advancements in our ability to prepare and detect correlations between individual photons. Its principles are increasingly translated into nanoscale characterization tools, furthering methods in spectroscopy, microscopy and metrology. In this Review, we discuss the rapid progress in this field driven by advanced technologies of single-photon detectors and quantum-light sources, including time-resolved single-photon counting cameras, superconducting nanowire single-photon detectors and entangled photon sources of increasing brightness. We emphasize emerging applications in super-resolution microscopy, measurements below classical noise limits and photon-number-resolved spectroscopy–a powerful paradigm for the characterization of nanoscale electronic materials. We conclude by discussing key technological challenges and future opportunities in materials science and bionanophotonics alike.
Fluorescence spectroscopy, Interference microscopy
Nature Physics
Optical signatures of interlayer electron coherence in a bilayer semiconductor
Original Paper | Condensed-matter physics | 2025-08-19 20:00 EDT
Xiaoling Liu, Nadine Leisgang, Pavel E. Dolgirev, Alexander A. Zibrov, Jiho Sung, Jue Wang, Takashi Taniguchi, Kenji Watanabe, Valentin Walther, Hongkun Park, Eugene Demler, Philip Kim, Mikhail D. Lukin
Emergent strongly correlated electronic phenomena in atomically thin transition-metal dichalcogenides are an exciting frontier in condensed matter physics, with examples ranging from bilayer superconductivity and electronic Wigner crystals to the ongoing search for exciton condensation. Here we take a step towards the latter by reporting experimental signatures of unconventional hybridization of the excitons with opposing dipoles consistent with coherence between interlayer electrons in a transition-metal dichalcogenide bilayer. We investigate naturally grown MoS2 homobilayers integrated in a dual-gate device structure allowing independent control of the electron density and out-of-plane electric field. By electron doping the bilayer when electron tunnelling between the layers is negligible, we observe that the two interlayer excitons hybridize, displaying unusual behaviour distinct from both conventional level crossing and anti-crossing. We show that these observations can be explained by quasi-static random coupling between the excitons, which increases with electron density and decreases with temperature. We argue that this phenomenon is indicative of a spatially fluctuating order parameter in the form of interlayer electron coherence, a theoretically predicted many-body state that has yet to be unambiguously established experimentally outside of the quantum Hall regime.
Condensed-matter physics, Optical spectroscopy, Two-dimensional materials
Physical Review Letters
Essay: Photonic Crystals as a Platform to Explore New Physics
Essay | Band gap | 2025-08-19 06:00 EDT
Che Ting Chan
In this PRL Essay, Che Ting Chan offers a forward-looking overview of photonic crystals and how their design flexibility, symmetry properties, and experimental accessibility position them as powerful tools for both fundamental studies and applied photonic technologies to explore a wide range of contemporary physical phenomena.
Phys. Rev. Lett. 135, 080001 (2025)
Band gap, Metamaterials, Phononic crystals, Photonic crystals, Photonics, Exceptional points
Surface-Morphology-Assisted Trapping of Strongly Coupled Electron-on-Neon Charge States
Research article | Quantum fluids & solids | 2025-08-19 06:00 EDT
Kaiwen Zheng, Xingrui Song, and Kater W. Murch
Single electrons confined to a free neon surface and manipulated through the circuit quantum electrodynamics architecture is a promising novel quantum computing platform. Understanding the exact physical nature of the electron-on-neon ($e\mathrm{Ne}$) charge states is important for realizing this platform’s potential for quantum technologies. We investigate how resonator trench depth and substrate surface properties influence the formation of $e\mathrm{Ne}$ charge states and their coupling to microwave resonators. Through experimental observation supported by modeling, we find that shallow-depth etching of the resonator features maximizes coupling strength. By comparing the trapping statistics and surface morphology of devices with altered trench roughness, our Letter reveals the role of fabrication-induced surface features in the formation of strongly coupled $e\mathrm{Ne}$ states.
Phys. Rev. Lett. 135, 080601 (2025)
Quantum fluids & solids, Qubits, Surfaces
Assessing Cosmological Evidence for Nonminimal Coupling
Research article | Alternative gravity theories | 2025-08-19 06:00 EDT
William J. Wolf, Carlos García-García, Theodore Anton, and Pedro G. Ferreira
The recent observational evidence of deviations from the Lambda cold dark matter model points toward the presence of evolving dark energy. The simplest possibility consists of a cosmological scalar field $\varphi $, dubbed ‘’quintessence,’’ driving the accelerated expansion. We assess the evidence for the existence of such a scalar field. We find that, if the accelerated expansion is driven by quintessence, the data favor a potential energy $V(\varphi )$ that is concave, i.e., ${m}^{2}={d}^{2}V/d{\varphi }^{2}<0$. Furthermore, and more significantly, the data strongly favor a scalar field that is nonminimally coupled to gravity [Bayes factor $\mathrm{log}(B)=7.34\pm{}0.6$], leading to time variations in the gravitational constant on cosmological scales, and the existence of fifth forces on smaller scales. The fact that we do not observe such fifth forces implies that either new physics must come into play on noncosmological scales or that quintessence is an unlikely explanation for the observed cosmic acceleration.
Phys. Rev. Lett. 135, 081001 (2025)
Alternative gravity theories, Cosmological constant, Cosmological parameters, Dark energy
Multimessenger Detection of Black Hole Binaries in Dark Matter Spikes
Research article | Gravitational waves | 2025-08-19 06:00 EDT
Fani Dosopoulou and Joseph Silk
We investigate the inspiral of a high mass-ratio black hole binary located in the nucleus of a galaxy, where the primary central black hole is surrounded by a dense dark matter spike formed through accretion during the black hole growth phase. Within this spike, dark matter undergoes strong self-annihilation, producing a compact source of $\gamma $-ray radiation that is highly sensitive to spike density, while the binary emits gravitational waves at frequencies detectable by LISA. As the inspiraling binary interacts with the surrounding dark matter particles, it alters the density of the spike, thereby influencing the $\gamma $-ray flux from dark matter annihilation. We demonstrate that the spike self-annihilation luminosity decreases by 10% to 90% of its initial value, depending on the initial density profile and binary mass ratio, as the binary sweeps through the LISA band. This presents a new opportunity to indirectly probe dark matter through multimessenger observations of galactic nuclei.
Phys. Rev. Lett. 135, 081401 (2025)
Gravitational waves, Particle dark matter
Toward a Robust Confirmation or Refutation of the Sterile-Neutrino Explanation of Short-Baseline Anomalies
Research article | Neutrino oscillations | 2025-08-19 06:00 EDT
Ohana Benevides Rodrigues, Matheus Hostert, Kevin J. Kelly, Bryce Littlejohn, Pedro A. N. Machado, Ibrahim Safa, and Tao Zhou
The sterile neutrino interpretation of the LSND and MiniBooNE neutrino anomalies is currently being tested at three liquid argon detectors: MicroBooNE, SBND, and ICARUS. It has been argued that a degeneracy between ${\nu }{\mu }\rightarrow {\nu }{e}$ and ${\nu }{e}\rightarrow {\nu }{e}$ oscillations significantly degrades their sensitivity to sterile neutrinos. Through an independent study, we show two methods to eliminate this concern. First, we resolve this degeneracy by including external constraints on ${\nu }_{e}$ disappearance from the PROSPECT reactor experiment. Second, by properly analyzing the full three-dimensional parameter space, we demonstrate that the stronger-than-sensitivity exclusion from MicroBooNE alone already covers the entire $2\sigma $ preferred regions of MiniBooNE at the level of $2- 3\sigma $. We show that upcoming searches at SBND and ICARUS can improve on this beyond the $4\sigma $ level, thereby providing a rigorous test of short-baseline anomalies.
Phys. Rev. Lett. 135, 081801 (2025)
Neutrino oscillations, Phenomenology, Neutrinos, Sterile neutrinos, Particle mixing & oscillations
Quantum Delocalization of a Levitated Nanoparticle
Research article | Coherent control | 2025-08-19 06:00 EDT
M. Rossi, A. Militaru, N. Carlon Zambon, A. Riera-Campeny, O. Romero-Isart, M. Frimmer, and L. Novotny
Researchers have expanded the quantum wave function of a levitated nanosphere, a step toward future tests of quantum physics.
Phys. Rev. Lett. 135, 083601 (2025)
Coherent control, Cooling & trapping, Micromechanical & nanomechanical oscillators
Co and CoPc Molecular Kondo Box on Gold Surface
Research article | Atomic & molecular structure | 2025-08-19 06:00 EDT
Xiangyang Li, Liang Zhu, Aidi Zhao, Yi Luo, J. G. Hou, Bin Li, Bing Wang, and Jinlong Yang
We demonstrate a class of Co and CoPc molecular Kondo boxes on the Au(111) surface through scanning tunneling microscopy experiments and first-principles calculations. The $\pi $-electron states of the CoPc molecule hybridize with the conduction electron states of the Au(111) substrate, imparting itinerantlike electron characteristics. Because of the high symmetry matching between the ${d}{\pi }$ orbitals of Co adatoms and the $\pi $ orbitals of CoPc, the large orbital overlap predominates the formation of a Kondo singlet within the molecular complexes that prevail over the competition from the metal substrate, enabling them effectively as the molecular Kondo boxes. Furthermore, increasing the number of Co adatoms and modulating the overall symmetry of the molecular Kondo box can effectively tune the Kondo temperature ${T}{\mathrm{K}}$.
Phys. Rev. Lett. 135, 086201 (2025)
Atomic & molecular structure, Density functional theory, Kondo effect, Magnetic interactions, Strongly correlated systems, Magnetic moment, Scanning tunneling microscopy
Universal Wilson Loop Bound of Quantum Geometry
Research article | Topological insulators | 2025-08-19 06:00 EDT
Jiabin Yu, Jonah Herzog-Arbeitman, and B. Andrei Bernevig
We define the absolute Wilson loop winding and prove that it bounds the (integrated) quantum metric from below. This Wilson loop lower bound naturally reproduces the known Chern and Euler bounds of the integrated quantum metric and provides an explicit lower bound of the integrated quantum metric due to the time-reversal protected ${\mathbb{Z}}{2}$ index, answering a hitherto open question. In general, the Wilson loop lower bound can be applied to any other topological invariants characterized by Wilson loop winding, such as the particle-hole ${\mathbb{Z}}{2}$ index. As physical consequences of the ${\mathbb{Z}}{2}$ bound, we show that the time-reversal ${\mathbb{Z}}{2}$ index bounds superfluid weight and optical conductivity from below and bounds the direct gap of a band insulator from above.
Phys. Rev. Lett. 135, 086401 (2025)
Topological insulators, Topological materials
Multistate Ferroelectricity Enabled by Electrically Controlled Phase Transition of Two-Dimensional Ices
Research article | Ferroelectricity | 2025-08-19 06:00 EDT
Junjie Fang, Wanlin Guo, and Hu Qiu
Multistate ferroelectric polarization holds promise for realizing high-density nonvolatile memory devices, but so far is restricted to a few traditional ferroelectrics. Here, we show that nanoconfined two-dimensional (2D) ferroelectric ice can achieve phase-dependent multistate polarization through extensive classical and ab initio molecular dynamics simulations. An in-plane electric field is found to induce the reversible transition between a low-polarization $AA$-stacked hexagonal ice phase and an unprecedented high-polarization $AB$-stacked ice phase, resulting in a four-state ferroelectric switching pathway. The findings highlight the potential of 2D ice as a functional material for the development of multistate ferroelectric memory devices.
Phys. Rev. Lett. 135, 086402 (2025)
Ferroelectricity, Ice, Liquid-solid interfaces, Liquids, Polarization, Ab initio molecular dynamics, Molecular dynamics
Two-Peak Heat Capacity Accounts for $R\mathrm{ln}(2)$ Entropy and Ground State Access in the Dipole-Octupole Pyrochlore ${\mathrm{Ce}}{2}{\text{Hf}}{2}{\mathrm{O}}_{7}$
Research article | Frustrated magnetism | 2025-08-19 06:00 EDT
E. M. Smith, A. Fitterman, R. Schäfer, B. Placke, A. Woods, S. Lee, S. H.-Y. Huang, J. Beare, S. Sharma, D. Chatterjee, C. Balz, M. B. Stone, A. I. Kolesnikov, A. R. Wildes, E. Kermarrec, G. M. Luke, O. Benton, R. Moessner, R. Movshovich, A. D. Bianchi, and B. D. Gaulin
Specific heat measurements of Ce2Hf2O7 down to 20 mK reveal a low-temperature peak consistent with a gapped ground state.
Phys. Rev. Lett. 135, 086702 (2025)
Frustrated magnetism, Quantum spin liquid, Spin ice, Pyrochlores, Cluster expansion, Neutron scattering, Quantum Monte Carlo, Specific heat measurements
Unveiling Three Types of Fermions in a Nodal Ring Topological Semimetal through Magneto-Optical Transitions
Research article | Optical conductivity | 2025-08-19 06:00 EDT
Jiwon Jeon, Taehyeok Kim, Jiho Jang, Hoil Kim, Mykhaylo Ozerov, Jun Sung Kim, Hongki Min, and Eunjip Choi
We investigate the quasiparticles of a single nodal ring semimetal ${\text{SrAs}}_{3}$ through axis-resolved magneto-optical measurements. We observe three types of Landau levels scaling as $\epsilon\sim \sqrt{B}$, $\epsilon\sim {B}^{2/3}$, and $\epsilon\sim B$ that correspond to Dirac, semi-Dirac, and classical fermions, respectively. Through theoretical analysis, we identify the distinct origins of these three types of fermions present within the nodal ring. In particular, semi-Dirac fermions—a novel type of fermion that can give rise to a range of unique quantum phenomena—emerge from the end points of the nodal ring where the energy band disperses linearly along one direction and quadratically along the perpendicular direction, a feature not achievable in nodal point or line structures. The capacity of the nodal ring to simultaneously host multiple fermion types, including semi-Dirac fermions, establishes it as a valuable platform to expand the understanding of topological semimetals.
Phys. Rev. Lett. 135, 086901 (2025)
Optical conductivity, Node-line semimetals, Fourier transform infrared spectroscopy, Optically detected magnetic resonance
Compact Metaplate with Bound State in the Continuum: From Quasisymmetry to Symmetry
Research article | Bound states in the continuum | 2025-08-19 06:00 EDT
Zhihui Wen, Penglin Gao, Jiawei Mao, Shoubo Dai, Marc Marti-Sabaté, Yabin Jin, Daniel Torrent, and Yegao Qu
Building localized states with high quality factors in compact dynamic systems could enhance the performance of wave control devices such as elastic filters and high-precision sensing devices. Here, we report on the theoretical and experimental investigation of symmetry-protected bound states in the continuum (BICs) in a compressed metaplate. The proposed theory establishes a Bessel-zero-directed multipolarization design that enables precise modulation for the frequencies and modes of BICs. Experimental results reveal a critical threshold for symmetric protection, beyond which the polarization mode of BICs still exists despite leakage modes. The measured quality factor of BICs in the cylindrical-shelled metaplate rises to 720 via symmetry translation. The metaplate shows an enhanced performance over conventional defect and topological modes. This work opens a route toward compact elastic devices for applications in fields like on-chip communication, elastic wave filtering, and high-precision sensing within tight environments.
Phys. Rev. Lett. 135, 087201 (2025)
Bound states in the continuum, Continuum mechanics, Elastic waves
Sparse Learning Enabled by Constraints on Connectivity and Function
Research article | Learning | 2025-08-19 06:00 EDT
Mirza M. Junaid Baig and Armen Stepanyants
Sparse connectivity is a hallmark of the brain and a desired property of artificial neural networks. It promotes energy efficiency, simplifies training, and enhances the robustness of network function. Thus, a detailed understanding of how to achieve sparsity without jeopardizing network performance is beneficial for neuroscience, deep learning, and neuromorphic computing applications. We used an exactly solvable model of associative learning to evaluate the effects of various sparsity-inducing constraints on connectivity and function. We determine the optimal level of sparsity achieved by the ${\ell }_{0}$ norm constraint and find that nearly the same efficiency can be obtained by eliminating weak connections. We show that this method of achieving sparsity can be implemented online, making it compatible with neuroscience and machine learning applications.
Phys. Rev. Lett. 135, 087301 (2025)
Learning, Memory, Machine learning, Machine learning models, Neuroscience, neural computation & artificial intelligence, Replica methods
Erratum: Nonrelativistic Holography from ${\mathrm{AdS}}{5}/{\mathrm{CFT}}{4}$ [Phys. Rev. Lett. 133, 151601 (2024)]
| 2025-08-19 06:00 EDT
Andrea Fontanella and Juan Miguel Nieto García
Phys. Rev. Lett. 135, 089901 (2025)
Physical Review X
Dynamical $α$-Rényi Entropies of Local Hamiltonians Grow at Most Linearly in Time
Research article | Quantum information theory | 2025-08-19 06:00 EDT
Daniele Toniolo and Sougato Bose
Linking the Lieb-Robinson bound to entanglement growth shows that faster information spread yields greater entanglement, providing a way to estimate computational complexity via measurable quantities.
Phys. Rev. X 15, 031046 (2025)
Quantum information theory
Rotations, Negative Eigenvalues, and Newton Method in Tensor Network Renormalization Group
Research article | Critical phenomena | 2025-08-19 06:00 EDT
Nikolay Ebel, Tom Kennedy, and Slava Rychkov
Incorporating lattice rotation into the renormalization group (RG) procedure offers a high-precision method for directly computing RG fixed-point tensors, paving the way for more rigorous and automated analysis of critical behavior in statistical physics.
Phys. Rev. X 15, 031047 (2025)
Critical phenomena, Phase transitions, Equilibrium lattice models, Ising model, Renormalization group, Tensor network methods, Tensor network renormalization
arXiv
Metastability in the parallel Ising model
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-20 20:00 EDT
Franco Bagnoli, Tommaso Matteuzzi
In this short paper we present some considerations about some parallel implementations of the dynamic (Monte Carlo) version of the Ising model. In some cases the equilibrium distribution of the parallel version does not present the symmetry breaking phenomenon in the low-temperature phase, i.e., the stochastic trajectory originated by the Monte Carlo simulation can jump between the distributions corresponding to both kinds of magnetization, or the lattice can break into two disjoint sublattices, each of which goes into a different asymptotic distribution. In this latter case, by introducing a small asynchronism, we can have a transition towards the standard ferromagnetic (or antiferromagnetic) distribution, with metastable transients.
Statistical Mechanics (cond-mat.stat-mech)
Central Limit Behavior at the Edge of Chaos in the z-Logistic Map
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-20 20:00 EDT
Abbas Ali Saberi, Ugur Tirnakli, Constantino Tsallis
We focus on the FeigenbaumCoulletTresser point of the dissipative one-dimensional z logistic map. We show that sums of iterates converge to q Gaussian distributions, which optimize the nonadditive entropic functional Sq under simple constraints. We derive a closedform prediction for the entropic index, and validate it numerically via data collapse for typical z values. The formula captures how the limiting law depends on the nonlinearity order and implies finite variance for z larger than 2 and divergent variance for z in between 1 and 2. These results extend edge of chaos central limit behavior beyond the standard case and provide a simple predictive law for unimodal maps with varying maximum order.
Statistical Mechanics (cond-mat.stat-mech), Chaotic Dynamics (nlin.CD)
15 pages, 5 figures
Fast hydrogen atom diffraction through monocrystalline graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-20 20:00 EDT
Pierre Guichard, Arnaud Dochain, Raphaël Marion, Pauline de Crombrugghe de Picquendaele, Nicolas Lejeune, Benoît Hackens, Paul-Antoine Hervieux, Xavier Urbain
We report fast atom diffraction through single-layer graphene using hydrogen atoms at kinetic energies from 150 to 1200 eV. High-resolution images reveal overlapping hexagonal patterns from coexisting monocrystalline domains. Time-of-flight tagging confirms negligible energy loss, making the method suitable for matter-wave interferometry. The diffraction is well described by the eikonal approximation, with accurate modeling requiring the full 3D interaction potential from DFT. Simpler models fail to reproduce the data, highlighting the exceptional sensitivity of diffraction patterns to atom-surface interactions and their potential for spectroscopic applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
6 pages and 5 figures (main text), 6 pages and 5 figures (supplemental material)
The Rise of Generative AI for Metal-Organic Framework Design and Synthesis
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Chenru Duan, Aditya Nandy, Shyam Chand Pal, Xin Yang, Wenhao Gao, Yuanqi Du, Hendrik Kraß, Yeonghun Kang, Varinia Bernales, Zuyang Ye, Tristan Pyle, Ray Yang, Zeqi Gu, Philippe Schwaller, Shengqian Ma, Shijing Sun, Alán Aspuru-Guzik, Seyed Mohamad Moosavi, Robert Wexler, Zhiling Zheng
Advances in generative artificial intelligence are transforming how metal-organic frameworks (MOFs) are designed and discovered. This Perspective introduces the shift from laborious enumeration of MOF candidates to generative approaches that can autonomously propose and synthesize in the laboratory new porous reticular structures on demand. We outline the progress of employing deep learning models, such as variational autoencoders, diffusion models, and large language model-based agents, that are fueled by the growing amount of available data from the MOF community and suggest novel crystalline materials designs. These generative tools can be combined with high-throughput computational screening and even automated experiments to form accelerated, closed-loop discovery pipelines. The result is a new paradigm for reticular chemistry in which AI algorithms more efficiently direct the search for high-performance MOF materials for clean air and energy applications. Finally, we highlight remaining challenges such as synthetic feasibility, dataset diversity, and the need for further integration of domain knowledge.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI)
10 pages, 5 figures
Magnetic and Mossbauer studies of Ca$x$Zn${1-x}$Fe$_2$O$_4$ nanoferrites
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Kemi Y. Adewale, Itegbeyogene P. Ezekiel
A one-step synthesis of Ca$ _x$ Zn$ _{1-x}$ Fe$ _2$ O$ _4$ (x=0, 0.5 and 1) nanoferrites and nanocomposites by the glycol-thermal method is reported. The structural, morphological and magnetic properties were studied using XRD, HRTEM, HRSEM, Mossbauer spectroscopy and VSM. The XRD patterns show a single phase cubic spinel structure for x=0. A composite phase of a spinel and hematite-like structure was observed for x=0.5, and for x=1, CaFe$ _2$ O$ _4$ has the same structure as hematite. The superparamagnetic nature of the samples was confirmed from the Mossbauer and magnetization results.
Materials Science (cond-mat.mtrl-sci)
7 pages
International Journal of Solid State Materials 2019
Synthesis and Characterization of Mg doped ZnFe$_2$O$_4$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Kemi Y. Adewale, Itegbeyogene P.Ezekiel
Single-phase Mg-doped ZnFe$ _2$ O$ _4$ nanoparticles with x= 0, 0.3, 0.5, 0.7 have been prepared by the glycol-thermal method without any subsequent calcination. The crystallite size, microstructure and magnetic properties of the prepared nanoparticles were studied using X-ray diffraction (XRD), high resolution scanning electron microscope (TEM), Mossbauer spectroscopy and vibrating sample magnetometer at room temperature. The XRD results revealed the production of a sharp single cubic spinel structure in all the synthesized samples without any impurity peak with the average crystallite size of about 19-28 nm. It was noticed that the lattice parameter varies as the Mg$ ^{2+}$ ion concentration increases. 57 Mossbauer measurement showed that the nano ferrites exhibit ferrimagnetic and superparamagnetic states. Magnetization measurements confirmed the superparamagnetic behaviour of the samples. The highest coercivity and saturation magnetization were observed at x=0.3. The saturation magnetization (MS) decreases while coercivity (HC) varies with an increase in the concentration of Mg$ ^{2+}$ ion.
Materials Science (cond-mat.mtrl-sci)
Research & Reviews: Journal of Physics 2020
Towards Capacitive In-Memory-computing: A perspective on the future of AI hardware
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Kapil Bhardwaj, Ella Paasio, Sayani Majumdar
The quest for energy-efficient, scalable neuromorphic computing has elevated compute-in-memory (CIM) architectures to the forefront of hardware innovation. While memristive memories have been extensively explored for synaptic implementation in CIM architectures, their inherent limitations, including static power dissipation, sneak-path currents, and interconnect voltage drops, pose significant challenges for large-scale deployment, particularly at advanced technology nodes. In contrast, capacitive memories offer a compelling alternative by enabling charge-domain computation with virtually zero static power loss, intrinsic immunity to sneak paths, and simplified selector-less crossbar operation, while offering superior compatibility with 3D Back-end-of-Line (BEOL) integration. This perspective highlights the architectural and device-level advantages of emerging non-volatile capacitive synapses. We examine how material engineering and interface control can modulate synaptic behavior, capacitive memory window and multilevel analog storage potential. Furthermore, we explore critical system-level trade-offs involving device-to-device variation, charge transfer noise, dynamic range, and effective analog resolution.
Materials Science (cond-mat.mtrl-sci)
When Does a Single Repulsive Dirac Cone Superconduct?
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-20 20:00 EDT
Superconductivity in a single two-dimensional Dirac cone offers a natural route to topological superconductivity. While usually considered extrinsic – arising from proximity to a conventional superconductor – we investigate when a doped Dirac cone can spontaneously develop superconductivity from a short-range repulsive interaction $ U$ via the Kohn–Luttinger mechanism. We show that an ideal, linear Dirac cone is immune to pairing at leading order in $ U^2$ . Superconductivity instead emerges only through higher-order in $ k$ corrections to the dispersion, which are unavoidable in any lattice realization and crucially dictate the pairing symmetry. The form of the pairing thus reflects how the well-known obstruction to realizing a single Dirac cone on a lattice is circumvented. When a Dirac cone arises from broken time-reversal symmetry – for instance, at a transition between Chern insulators or in a valley-polarized phase – we find a topological $ p - ip$ state whose chirality is opposite to that of the parent chiral metal above $ T_c$ . By contrast, for a surface Dirac cone of a 3D topological insulator, superconductivity is stabilized by anisotropies in the dispersion. For $ C_{3v}$ -symmetric warping, as in $ \mathrm{Bi}{2}\mathrm{Te}{3}$ , pairing is strongest when the Fermi surface becomes hexagonal, leading to order in the $ (d \pm id)\times(p+ip)$ channel with accidental near-nodes. In the highly anisotropic limit $ v_x \gg v_y$ , relevant to side surfaces of layered materials, the Fermi surface splits into two branches, and nesting favors a pairing symmetry $ \Delta \sim \mathrm{sgn}(k_x)\cos(k_y)$ reminiscent of organic superconductors.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 9 figures
Generalized Brillouin Zone Fragmentation
New Submission | Other Condensed Matter (cond-mat.other) | 2025-08-20 20:00 EDT
Haiyu Meng, Yee Sin Ang, Ching Hua Lee
The Generalized Brillouin Zone (GBZ) encodes how lattice momentum is complex-deformed due to non-Hermitian skin accumulation, and has proved essential in restoring bulk-boundary correspondences. However, we find that generically, the GBZ is neither unique nor well-defined if more than one skin localization direction or strength exists, even in systems with no asymmetric hoppings. Instead, open boundary condition (OBC) eigenstates become complicated superpositions of multiple competing skin modes from “fragments” of all possible GBZs solutions. We develop a formalism that computes the fragmented GBZ in a scalable manner, with fragmentation extent quantified through our newly-defined composition IPR and spectral relative entropy. GBZ fragmentation is revealed to fundamentally challenge the notion of discontinuous phase transitions, since topological winding contributions from different GBZ fragments can “melt away” at different rates. Phenomenologically, GBZ fragmentation also leads to edge localization in all observables in energetically weighted ensembles such as thermal ensembles. This contrasts with conventional GBZs where the skin localization completely cancels in biorthogonal expectations. Occurring universally in multi-mode non-Hermitian media, as we concretely demonstrate with photonic crystal simulations, GBZ fragmentation points towards a new paradigm that is essential for understanding the band structure and the topological and dynamical properties of diverse generic non-Hermitian systems.
Other Condensed Matter (cond-mat.other), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas), Optics (physics.optics), Quantum Physics (quant-ph)
35 pages, 24 figures
Numerical Simulation of Lead-Free Absorbers in 2D Dion-Jacobson Phase Perovskite Solar Cells Using SCAPS-1D: Towards 41% Efficiency
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Md. Meraz Hasan, Pallab Chakraborty, Fahim Tanvir, Subah Tahsin, Mostafizur Rahaman
With the rapid advancement of photovoltaic science, there has been an increasing focus on the development of environment-friendly and structurally advanced perovskite solar cells (PSCs). In this context, this study investigates an architectural configuration employing 2D Dion-Jacobson phase perovskites as both electron and hole transport layers within a 2D/absorber/2D structure. The primary objective is to identify optimal absorber materials and enhance the overall efficiency of the device. While the reduction of lead content remains a significant challenge in PSC development, the present work focuses on the evaluation of seven lead-free absorber materials: MASnBr3, Sr3PI3/Sr3SbI3, p-CuBi2O4, p-Si, CH3NH3SnI3, Sb2Se3, and CZTSSe. These materials were assessed in the context of an FTO/PeDAMA8Pb6I19/IDL1/absorber/IDL2/PeDAMA2Pb3I10/C architecture utilizing SCAPS-1D simulation software. The study includes a comprehensive analysis of band alignment, pre-optimization screening, and performance optimization through the adjustment of absorber thickness, doping levels, and defect densities. Additionally, the temperature sensitivity and the substitution of the FTO layer with ITO, IZO, and MZO were also investigated. The simulation results indicated that Sb2Se3 and CZTSSe achieved the highest efficiencies of 41.00% and 41.19%, respectively. Furthermore, MZO was identified as a strong candidate for replacing FTO, maintaining consistent performance across all absorber types analyzed. Overall, this study provides a comparative framework for the material selection within layered PSC architectures and significantly contributes to the advancement of stable, efficient, and lead-free photovoltaic technologies.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
Persistence of charge density wave fluctuations in the absence of long-range order in a hole-doped kagome metal
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-20 20:00 EDT
Terawit Kongruengkit, Andrea N. Capa Salinas, Ganesh Pokharel, Brenden R. Ortiz, Stephen D. Wilson, John W. Harter
The kagome metals $ A$ V$ _3$ Sb$ _5$ ($ A$ = K, Rb, Cs) exhibit a complex interplay between charge density wave (CDW) order and superconductivity. In this study, we use ultrafast coherent phonon spectroscopy to probe the evolution of CDW order in hole-doped CsV$ _3$ Sb$ _{5-x}$ Sn$ x$ across a broad range of compositions ($ 0 \leq x \leq 0.68$ ). While thermodynamic and diffraction measurements show long-range CDW order vanishes above $ x \approx 0.05$ , we observe persistent signatures of CDW fluctuations up to the highest doping levels, with correlation times on the order of several picoseconds. These results indicate the presence of robust fluctuating charge order that survives well beyond the established CDW phase boundary. Furthermore, these fluctuations are enhanced near a doping-tuned quantum phase transition at $ x^\ast \approx 0.15$ , which coincides with a local minimum in the superconducting $ T\mathrm{c}$ double-dome. Additional measurements on Ti- and K-substituted samples confirm that this behavior is intrinsic to hole doping and not tied to disorder. Overall, our findings suggest that CDW fluctuations play a central role in the electronic phase diagram of $ A$ V$ _3$ Sb$ _5$ and may mediate or compete with superconductivity.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
PBPU Elastomer Network Architecture Determination via Corresponding States Analysis of Mechanical Behavior
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-20 20:00 EDT
Sushanta Das (Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India Defence Research and Development Organization, New Delhi, India), Hari Ramakrishna Sudhakar (Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India), Hemant Nanavati (Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India)
In this work we examine the effect of R=[NCO]/[OH] in the R=<1 regime, on the resultant structural topology of polybutadiene polyurethane (PBPU) elastomer networks based on hydroxy-terminated polybutadiene (HTPB). We employ stress-elongation behavior and its modeling, as a tool. We examine this property via a combination of our model for the finite chain phantom networks incorporating the HTPB structural information, with the slip-tube model from the literature, suitably modified phenomenologically. We implement a further normalized Mooney-Rivlin (MR) representation (corresponding deformation states plots), to remove any magnitude bias on the model parameters. The now revealed curvatures of all the MR plots, in turn, reveals the non-correlation between the chain size and crosslink density. This discrepancy occurs due to the R-dependent majority presence of network defects due to sol effects (as obtained from swelling experiments) and non-load bearing pendant branches on the load-bearing network chains.
Soft Condensed Matter (cond-mat.soft)
39 Pages (20 Pages Main Text, 12 Pages Appendices), 24 Figures (13 Figures in Main Text, 11 Figures in Appendix)
Engineering Hubbard models with gated two-dimensional moiré systems
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-20 20:00 EDT
Yiqi Yang, Yubo Yang, Miguel A. Morales, Shiwei Zhang
Lattice models are powerful tools for studying strongly correlated quantum many-body systems, but their general lack of exact solutions motivates efforts to simulate them in tunable platforms. Recently, a promising new candidate has emerged for such platforms from two-dimensional materials. A subset of moiré systems can be effectively described as a two-dimensional electron gas (2D EG) subject to a moiré potential, with electron-electron interactions screened by nearby metallic gates. In this paper, we investigate the realization of lattice models in such systems. We show that, by controlling the gate separation, a 2D EG in a square moiré potential can be systematically tuned into a system whose ground state exhibits orders analogous to those of the square lattice Hubbard model, including the stripe phase. Furthermore, we study how variations in gate separation and moiré potential depth affect the ground-state orders. A number of antiferromagnetic phases, as well as a ferromagnetic phase and a paramagnetic phase, are identified. We then apply our quantitative downfolding approach to triangular moiré systems closer to current experimental conditions, compare them with the square lattice parameters studied, and outline routes for experimental realization of the phases.
Strongly Correlated Electrons (cond-mat.str-el)
11 pages, 12 figures
Generalized Algebra Grounded on Nonadditive Entropies
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-20 20:00 EDT
Leandro Lyra Braga Dognini, Constantino Tsallis
A $ N$ -body system is simple if all associated physically relevant space-time correlations are short-ranged, meaning that their momenta of all orders are finite. Such systems typically have a total number $ W$ of admissible microscopic configurations which grows with $ N$ as $ W(N) \sim \mu^N;(\mu >1, , N\to\infty)$ . Their thermostatistical properties are known to be satisfactorily handled within Boltzmann-Gibbs (BG) statistical mechanics. In contrast, a system is complex if one or more associated correlations are long-ranged. The simplest examples of such systems are those for which $ W(N) \sim N^\rho;;(\rho>0)$ . A generalized statistical mechanics grounded on the nonadditive entropic functional $ S_q({p_{i}})=k\sum_{i=1}^W p_i \ln_q \frac{1}{p_i} ;;(q\in \mathbb{R}, ;S_1=S_{BG})$ with $ \ln_q z =\frac{z^{1-q}-1}{1-q}$ ($ \ln_1 z=\ln z$ ) satisfactorily handles such systems. Indeed, for equiprobabilities, $ S_{q=1-1/\rho}({1/W(N)})=k\ln_{1-1/\rho} W(N) \propto N$ . Furthermore, for complex systems, the size of the corresponding phase spaces can be related to the property $ \ln_q (x\otimes_q y) =\ln_q x + \ln_q y$ , $ x,y\geq1$ , $ q\leq 1$ , where $ x\otimes_q y=[x^{1-q}+y^{1-q}-1]^{\frac{1}{1-q}}{+};;(x\otimes_1 y=xy)$ , and the $ q$ -product $ \otimes_q$ grounds the definition of a $ q$ -generalized algebra. Another class of complex systems corresponds to $ W(N) \sim \nu^{N^\gamma};;(\nu >1, ,\gamma > 0)$ , which appears to be the case of black holes and other cosmological phenomena. This class can be handled with $ S\delta({p_{i}}) = k\sum_{i=1}^W p_i \Bigl(\ln \frac{1}{p_i} \Bigr)^\delta ;;(\delta>0)$ . Finally, we can define $ S_{q,\delta}({p_{i}})=k\sum_{i=1}^W p_i \Bigl(\ln_q \frac{1}{p_i} \Bigr)^\delta$ $ (q\in\mathbb{R},\delta>0)$ , which unifies all the above ones. In this paper, we generalize the $ q$ -algebra to a new, promising one, namely the $ (q,\delta)$ -algebra.
Statistical Mechanics (cond-mat.stat-mech), Mathematical Physics (math-ph)
A Haldane-Anderson Hamiltonian Model for Hyperthermal Hydrogen Scattering from a Semiconductor Surface
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Xuexun Lu, Nils Hertl, Reinhard J. Maurer
Collisions of atoms and molecules with metal surfaces create electronic excitations in the metal, leading to nonadiabatic energy dissipation, inelastic scattering, and sticking. Mixed quantum-classical molecular dynamics simulation methods, such as molecular dynamics with electronic friction, are able to capture nonadiabatic energy loss during dynamics at metal surfaces. Hydrogen atom scattering on semiconductors, on the other hand, exhibits strong adsorbate-surface energy transfer only when the projectile kinetic energy exceeds the bandgap of the substrate. Electronic friction fails to describe this effect. Here, we report a first-principles parameterization of a simple Haldane-Anderson Hamiltonian model of hydrogen atom gas-surface scattering on $ c(2\times8)$ Ge(111), for which hyperthermal scattering experiments have been reported. We subsequently perform independent electron surface hopping and Ehrenfest dynamics simulations on this model. Whereas mean-field dynamics yield weak nonadiabatic energy loss that is independent of the initial kinetic energy, independent electron surface hopping simulations qualitatively agree with the experimental observation that nonadiabatic energy dissipation only occurs if the initial kinetic energy exceeds the bandgap of the surface. We further show how nonadiabatic energy loss affects sticking, which is yet to be experimentally measured.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)
12 pages, 7 figures
Fiber bundle model of thermally activated creep failure
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-20 20:00 EDT
Stefan Hiemer, Paolo Moretti, Stefano Zapperi, Michael Zaiser
An equal load sharing fiber bundle model for thermally activated breakdown is developed using transition state theory to describe the rate of elementary failures. The lifetime distribution, average, variance and their asymptotic limits for uniform fiber failure thresholds are derived and found to be in excellent agreement with simulations. The asymptotic scaling with regards to the number of fibers matches analytical approximations in the low temperature limit derived by Roux and co-workers for a model of thermal breakdown by stationary Gaussian noise. For the case of randomly distributed fiber failure strengths, the lifetime distribution is derived as a multidimensional integral with no closed form solution. Simulations with different fiber strength distributions indicate that, in the limit of large fiber numbers, the statistics of bundle lifetimes shows a similar asymptotic scaling for distributed and for uniform thresholds. Fiber breakage by thermal activation occurs in avalanches triggered by individual thermally activated failure events, and the asymptotic avalanche size distribution obtained from the simulations matches earlier theoretical results derived for quasistatic loading.
Statistical Mechanics (cond-mat.stat-mech), Materials Science (cond-mat.mtrl-sci)
Expanding the search space of high entropy oxides and predicting synthesizability using machine learning interatomic potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Oliver A. Dicks, Solveig S. Aamlid, Alannah M. Hallas, Joerg Rottler
We propose an efficient computational methodology for predicting the synthesizability of high entropy oxides (HEOs) in a large space of possible candidate compounds. HEOs are a growing field with an enormous potential chemical composition space, and yet the discovery of new HEOs is slow and driven by experimental trial-and-error. In this work, we attempt to speed up this process by using a machine learned interatomic potential offering DFT-level accuracy. Our methodology starts by identifying a set of crystal structures and elements for screening, building a large random unit cell of each composition and structure, then relaxing this structure. The most promising candidates are distinguished based on the variance of the individual cation energies, which we introduce as our entropy descriptor, and the enthalpy of mixing, which is used as the enthalpy descriptor. The approach is applied to tetravalent HEOs, and its validity is confirmed by comparison to alternative descriptors and DFT calculations for a set of 7 elements. The search is then extended to a set of 14 elements and three crystal structures, where it successfully identifies the only known stable 4-component HEO in the $ \alpha$ -PbO$ _2$ structure, as well as predicting several new 5-component candidate systems. This approach can straightforwardly be applied to new sets of elements and structures, allowing for the accelerated discovery of new HEOs.
Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn)
$p$-orbital self-organization of ultracold atoms coupled to optical cavities
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-20 20:00 EDT
Hui Tan, Pengfei Zhang, Jianmin Yuan, Yongqiang Li
Atoms coupled to optical cavities provide a novel platform for understanding high-orbital exotic phenomena in strongly correlated materials. In this study, we investigate strongly correlated ultracold bosonic gases that are coupled to two orthogonally arranged optical cavities and driven by a blue-detuned running-wave laser field. Our results demonstrate that atoms initially in the $ s$ -orbital state can be scattered into $ p_x$ - and $ p_y$ -orbital states in either a symmetric or asymmetric manner, depending on the frequencies of the two cavities. For the symmetric configuration, we observe that atoms are scattered into the $ p_x$ - and $ p_y$ -orbitals equally. In the asymmetric case, photons emitted into one cavity mode suppress the scattering into the orthogonal mode. Notably, the coupling of atoms with multiple cavity modes leads to the emergence of high-orbital self-organized phases, accompanied by orbital-density waves that break different symmetries.
Quantum Gases (cond-mat.quant-gas)
Josephson diode effect in nanowire-based Andreev molecules
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-20 20:00 EDT
Shang Zhu, Yiwen Ma, Jiangbo He, Xiaozhou Yang, Zhongmou Jia, Min Wei, Yiping Jiao, Jiezhong He, Enna Zhuo, Xuewei Cao, Bingbing Tong, Ziwei Dou, Peiling Li, Jie Shen, Xiaohui Song, Zhaozheng Lyu, Guangtong Liu, Dong Pan, Jianhua Zhao, Bo Lu, Li Lu, Fanming Qu
Superconducting systems exhibit non-reciprocal current transport under certain conditions of symmetry breaking, a phenomenon known as the superconducting diode effect. This effect allows for perfect rectification of supercurrent, and has received considerable research interest. We report the observation of the Josephson diode effect (JDE) in nanowire-based Andreev molecules, where the time-reversal and spatial-inversion symmetries of a Josephson junction (JJ) can be nonlocally broken by coherently coupling to another JJ. The JDE can be controlled using both non-local phase and gate voltages. Notably, the non-local phase can induce a sign reversal of the diode efficiency, a manifestation of regulating the probabilities of double elastic cotunneling and double-crossed Andreev reflection. Additionally, the diode efficiency can be further modulated by local and non-local gate voltages, exhibiting a central-peak feature in the gate-voltage space. Our theoretical calculations of the energy spectrum and the Josephson currents align well with the experimental results. These results demonstrate the non-local regulation of the JDE in Andreev molecules, offering significant implications for the control of multi-JJ devices and the development of advanced superconducting devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
25 pages, 13 figures
Dislocation-mediated short-range order evolution during thermomechanical processing
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Mahmudul Islam, Killian Sheriff, Rodrigo Freitas
Thermomechanical processing alters the microstructure of metallic alloys through coupled plastic deformation and thermal exposure, with dislocation motion driving plasticity and microstructural evolution. Our previous work showed that the same dislocation motion both creates and destroys chemical short-range order (SRO), driving alloys into far-from-equilibrium SRO states. However, the connection between this dislocation-mediated SRO evolution and processing parameters remains largely unexplored. Here, we perform large-scale atomistic simulations of thermomechanical processing of equiatomic TiTaVW to determine how temperature and strain rate control SRO via competing creation ($ \Gamma$ ) and annihilation ($ \lambda$ ) rates. Using machine learning interatomic potentials and information-theoretic metrics, we quantify that the magnitude and chemical character of SRO vary systematically with these parameters. We identify two regimes: a low-temperature regime with weak strain-rate sensitivity, and a high-temperature regime in which reduced dislocation density and increased screw character amplify chemical bias and accelerate SRO formation. The resulting steady-state SRO is far-from-equilibrium and cannot be produced by equilibrium thermal annealing. Together, these results provide a mechanistic and predictive link between processing parameters, dislocation physics, and SRO evolution in chemically complex alloys.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages, 5 figures
Charge Ordering and Magnetic Exchange in the Ladder-Type Compound NH$_4$V$_2$O$_5$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-20 20:00 EDT
The low-temperature electronic and magnetic properties of NH$ _4$ V$ _2$ O$ _5$ , an isoelectronic analog of the spin-ladder compound $ \alpha’$ -NaV$ _2$ O$ _5$ , are investigated using DFT+$ U$ calculations. Two charge-ordering patterns - zigzag and linear chains of V$ ^{4+}$ /V$ ^{5+}$ ions - are considered. The zigzag configuration is found to be energetically preferred and exhibits insulating behavior with a band gap of 1.7 eV. In this state, magnetic V$ ^{4+}$ (d$ ^1$ ) ions form antiferromagnetically coupled spin chains. Calculated exchange interactions reveal strong diagonal (intrarung) and interladder couplings, indicating a complex spin-ladder network. These results suggest that NH$ _4$ V$ _2$ O$ _5$ retains essential spin-ladder characteristics while displaying new structural and magnetic features arising from the larger size and non-spherical geometry of the NH$ _4^+$ ion compared to Na$ ^+$ .
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Unified description of spin-lattice coupling: application to thermodynamic properties of the pyrochlore Heisenberg antiferromagnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-20 20:00 EDT
Masaki Gen, Hidemaro Suwa, Shusaku Imajo, Chao Dong, Hiroaki Ueda, Makoto Tachibana, Akihiko Ikeda, Koichi Kindo, Yoshimitsu Kohama
We present an extended model to describe the spin-lattice coupling, incorporating individual vibrations of bonds and atomic sites alongside distance-dependent exchange interactions. The proposed spin Hamiltonian can be effectively considered as an interpolation between two well-established minimum models, the bond-phonon model and the site-phonon model. The extended model well reproduces successive field-induced phase transitions as well as the thermodynamic properties of a 3-up-1-down state in the pyrochlore-lattice Heisenberg antiferromagnet, including negative thermal expansion, an enhanced magnetocaloric effect, and a sharp specific-heat peak. Our approach is broadly applicable to various spin models, providing a framework for identifying the primary phonon modes responsible for spin-lattice coupling and for understanding complex magnetic phase diagrams.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
6 pages, 4 figures, SM: 6 pages, 5 figures
Physics-Informed Neural Networks for Programmable Origami Metamaterials with Controlled Deployment
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-20 20:00 EDT
Sukheon Kang, Youngkwon Kim, Jinkyu Yang, Seunghwa Ryu
Origami-inspired structures provide unprecedented opportunities for creating lightweight, deployable systems with programmable mechanical responses. However, their design remains challenging due to complex nonlinear mechanics, multistability, and the need for precise control of deployment forces. Here, we present a physics-informed neural network (PINN) framework for both forward prediction and inverse design of conical Kresling origami (CKO) without requiring pre-collected training data. By embedding mechanical equilibrium equations directly into the learning process, the model predicts complete energy landscapes with high accuracy while minimizing non-physical artifacts. The inverse design routine specifies both target stable-state heights and separating energy barriers, enabling freeform programming of the entire energy curve. This capability is extended to hierarchical CKO assemblies, where sequential layer-by-layer deployment is achieved through programmed barrier magnitudes. Finite element simulations and experiments on physical prototypes validate the designed deployment sequences and barrier ratios, confirming the robustness of the approach. This work establishes a versatile, data-free route for programming complex mechanical energy landscapes in origami-inspired metamaterials, offering broad potential for deployable aerospace systems, morphing structures, and soft robotic actuators.
Soft Condensed Matter (cond-mat.soft), Artificial Intelligence (cs.AI), Computational Physics (physics.comp-ph)
Chiral Phonons in a Cubic Lattice
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-20 20:00 EDT
Hirokazu Tsunetsugu, Hiroaki Kusunose
We have developed a theory for the energy dispersion of chiral phonons in a simplest cubic lattice. Among all the phonon modes, only the optical triplet modes exhibit the intrinsic characteristics of chiral phonons near k=0, and we examine their energy splitting in detail by analyzing the dynamical matrix. To first order in k, the splitting is described by a spin-1 Weyl Hamiltonian, and helicity becomes a good quantum number. It asymptotically coincides with the crystal angular momentum for k parallel <111> up to a global sign. The Hamiltonian incorporates a pseudoscalar coupling constant associated with electric toroidal monopoles, determined by the spatial configuration of the stiffness tensors.
Strongly Correlated Electrons (cond-mat.str-el)
5 pages, 3 figures
Realization and characterization of an all-bands-flat electronic lattice
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-20 20:00 EDT
Noah Lape, Simon Diubenkov, L.Q. English, P.G. Kevrekidis, Alexei Andreanov, Yeongjun Kim, Sergej Flach
We construct an electronic all-bands-flat (ABF) lattice and experimentally generate compact localized states (CLSs) therein. The lattice is a diamond (rhombic) chain and implemented as a network of capacitors and inductors, as well as voltage inverters (using operational amplifiers) in order to introduce a (\pi)-phase flux within each diamond. The network’s normal modes split into three flat bands, and the corresponding CLSs can be excited in isolation via a two-node driving at the flat band frequencies. We also examine the role of the lattice edges and their interaction with the CLSs. Finally, we compare the experimental results to tight-binding predictions and obtain very good agreement. This analysis paves the way for further experimental implementations of ABF systems in electric networks, especially with an eye towards exploring their interplay with nonlinearity.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Pattern Formation and Solitons (nlin.PS)
Overcoming Quantum Resistivity Scaling in Nanoscale Interconnects Using Delafossite PdCoO2
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Seoung-Hun Kang, Youngjun Lee, Sangmoon Yoon, JongMok Ok, Mina Yoon, Ho Nyung Lee, Young-Kyun Kwon
Continued scaling into the sub 7 nm regime exacerbates quantum limited resistivity in Cu interconnects. We evaluated layered PdCoO2 and explicitly benchmarked it against Cu to identify mechanisms that maintain conductivity under confinement. Using a momentum resolved relaxation time formalism derived from the conductivity tensor, we link k and energy resolved velocities, life times, and mean free paths (MFPs) to thickness dependent resistivity for films and wires. PdCoO2 exhibits quasi 2D transport with high inplane velocities and strongly anisotropic MFPs (15 nm inplane, 3 nm outofplane near EF), whereas Cu shows an isotropic 22 nm MFP. Under identical boundary conditions including a realistic 2 nm liner/diffusion barrier for Cu, PdCoO2 displays suppressed boundary scattering and a much slower resistivity increase from bulk down to sub 30 nm, preserving near bulk conductivity and remaining viable at 2 nm. Thickness trends reveal dual slope changes in PdCoO2 (35 nm and 7 nm) set by anisotropic MFPs, contrasting with the single characteristic scale of Cu (40 nm). The calculated bulk values and scaling curves track available measurements for both materials. These results establish PdCoO2 as a scalable interconnect that outperforms Cu under quantum confinement and provide a quantitative framework to screen layered conductors for next generation nanoelectronic interconnects.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Deterministic N’eel vector switching of altermagnets via magnetic multipole torque
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Seungyun Han, Kyoung-Whan Kim, Hyun-Woo Lee, Suik Cheon
Altermagnets have recently emerged as promising materials for next-generation spintronic devices. For their device applications, realizing a single-domain configuration is essential but remains challenging. We theoretically consider injecting magnetic multipoles into altermagnets, which can be achieved by applying an in-plane current to an altermagnet/normal metal bilayer. We demonstrate for $ d$ -wave altermagnets that the torque generated by the magnetic octupole injection can achieve magnetic-field-free deterministic switching of the altermagnets’ Néel vector and transform their multidomain configurations into a single domain. This method allows the switching in diverse altermagnets, thereby facilitating their device applications and fundamental studies. This work also exemplifies the usefulness of magnetic multipole currents.
Materials Science (cond-mat.mtrl-sci)
7 pages, 3 figures
Experimental Confirmation of Hyperuniformity of torque fluctuations in Frictional Matter
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-20 20:00 EDT
Jin Shang, Jie Zhang, Itamar Procaccia
A recent purely theoretical prediction stated that in frictional granular packings, mechanical balance and material isotropy constrain the stress auto-correlation matrix to be fully determined by two spatially isotropic functions: the pressure and torque auto-correlations. Moreover, and unexpectedly, the torque fluctuations were predicted to be hyperuniform, a condition for the stress auto-correlation to decay as the elastic Green’s function. In this Letter we present first experimental evidence for the hyperuniformity of the stress fluctuations. We propose that quite generally the variance of torque fluctuations in a d-dimensional ball of radius R will increase exactly like $ R^{d-1}$ , satisfying the definition of hyperuniformity.
Soft Condensed Matter (cond-mat.soft)
4 pages, 4 figures
Unlocking reversible and nonvolatile anomalous valley Hall control through multiferroic van der Waals heterostructures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Ankita Phutela, Saswata Bhattacharya
Achieving external control over the anomalous valley Hall (AVH) effect is essential for advancing valleytronic applications. However, many of the existing approaches suffer from limitations such as irreversibility or volatility. In this work, we propose a general strategy for enabling nonvolatile electrical tuning of the AVH effect by utilizing multiferroic van der Waals heterostructures. Using first-principles density functional theory calculations, we demonstrate that a heterostructure composed of a ferromagnetic monolayer VSSe and a ferroelectric monolayer Al$ _2$ S$ _3$ permits fine control of valley transport properties. The AVH response in VSSe can be reversibly and nonvolatility switched by reversing the polarization of Al$ _2$ S$ _3$ via an applied electric field. This ferroelectric mechanism ensures a stable valley state even without continuous energy input. Furthermore, the valley polarization can also be inverted through the same polarization switching process, providing a dual degree of control over valley-dependent phenomena. These findings establish a promising pathway toward intrinsically switchable and energy-efficient valleytronic devices.
Materials Science (cond-mat.mtrl-sci)
Real-time bubble nucleation and growth for false vacuum decay on the lattice
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-20 20:00 EDT
Daan Maertens, Jutho Haegeman, Karel Van Acoleyen
We revisit quantum false vacuum decay for the one-dimensional Ising model, focusing on the real-time nucleation and growth of true vacuum bubbles. Via matrix product state simulations, we demonstrate that for a wide range of parameters, the full time-dependent quantum state is well described by a Gaussian ansatz in terms of domain wall operators, with the associated vacuum bubble wave function evolving according to the linearized time-dependent variational principle. The emerging picture shows three different stages of evolution: an initial nucleation of small bubbles, followed by semi-classical bubble growth, which in turn is halted by the lattice phenomenon of Bloch oscillations. Furthermore, we find that the resonant bubble only plays a significant role in a certain region of parameter-space. However, when significant, it does lead to an approximately constant decay rate during the intermediate stage. Moreover, this rate is in quantitative agreement with the analytical result of Rutkevich (Phys. Rev. B 60, 14525) for which we provide an independent derivation based on the Gaussian ansatz.
Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Lattice (hep-lat), High Energy Physics - Theory (hep-th), Quantum Physics (quant-ph)
21 pages, 8 figures
Unravelling disorder in kagome Yb$_{0.5}$Co$_3$Ge$_3$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-20 20:00 EDT
A. Korshunov, C. A. Fuller, C.-Y. Lim, A. Kar, S. Roychowdhury, D. Chernyshov, C. Shekhar, A. Bosak, C. Felser, S. Blanco-Canosa
The presence of phonon instabilities that leads to the formation of charge modulated states in kagome metals has allowed their classification based on the atomic displacements. Here, we use diffuse and inelastic x-ray scattering, backed by Monte Carlo simulations to describe a type-I instability in the kagome metal Yb$ _{0.5}$ Co$ _3$ Ge$ _3$ . We find that the in-plane distortion of Co in the kagome plane drives a structural transition with the appearance of new Bragg peaks at odd $ L$ , which are surrounded by a hexagonal diffuse signal. The anisotropic diffuse scattering, characteristic of a highly frustrated triangular lattice was simulated following a combination of Ising hamiltonian and Lennard-Jones potential, and demonstrate that the structural phase transition in Yb$ _{0.5}$ Co$ _3$ Ge$ _3$ is of an order-disorder transformation type. The inelastic spectra reveals no softening but an anomalous broadening of the $ \Gamma-A$ low energy acoustic mode. Our results highlight the critical role of the geometric frustration in promoting ordering from disorder in kagome lattices and power of diffuse scattering to disentangle the internal atomic displacements and correlated disorder.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
9 pages, 5 figures
Evidence for single variant in altermagnetic RuO2(101) thin films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Cong He, Zhenchao Wen, Jun Okabayashi, Yoshio Miura, Tianyi Ma, Tadakatsu Ohkubo, Takeshi Seki, Hiroaki Sukegawa, Seiji Mitani
Altermagnetism presents intriguing possibilities for spintronic devices due to its unique combination of strong spin-splitting and zero net magnetization. However, realizing its full potential hinges on fabricating single-variant altermagnetic thin films. In this work, we present definitive evidence for the formation of single-variant altermagnetic RuO2(101) thin films with fully epitaxial growth on Al2O3(1-102) r-plane substrates, confirmed through rigorous structural analyses using X-ray diffraction, atomic-resolution transmission electron microscopy and X-ray magnetic linear dichroism. The mutual correspondence of the occupancy of oxygen atoms on the surfaces of RuO2(101)[010] and Al2O3(1-102)[11-20] plays a decisive role in the formation of the single-variant RuO2, which is also supported by our first-principles density functional theory calculations. We further observed spin-splitting magnetoresistance in the single-variant RuO2(101)/CoFeB bilayers, highlighting the characteristic effect of single variant on spin transport. The demonstration of single-variant RuO2(101) films marks a significant advancement in the field of altermagnetism and paves the way for exploring their potential applications.
Materials Science (cond-mat.mtrl-sci)
38 pages, 13 figures
The properties of the nitrogen-vacancy center in milled chemical vapor deposition nanodiamonds
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-20 20:00 EDT
Alessandro Mameli, Giannis Thalassinos, Marco Capelli, Johannes Ackermann, Edwin Mayes, Hiroshi Abe, Takeshi Ohshima, Tingpeng Luo, Volker Cimalla, Peter Knittel, Brant Gibson, Jan Jeske, Nikolai Dontschuk, Anke Krueger, Alastair Stacey, Alexander Healey, Philipp Reineck
Fluorescent nanodiamonds (FNDs) containing negatively charged nitrogen-vacancy (NV-) centers are vital for many emerging quantum sensing applications from magnetometry to intracellular sensing in biology. However, developing a scalable fabrication method for FNDs hosting color centers with consistent bulk-like photoluminescence (PL) and spin coherence properties remains a highly desired but unrealized goal. Here, we investigate optimized ball milling of single-crystal diamonds produced via chemical vapor deposition (CVD) and containing 2 ppm of substitutional nitrogen and 0.3 ppm of NV- to achieve this goal. The NV charge state, PL lifetime, and spin properties of bulk CVD diamond samples are directly compared to milled CVD FNDs and commercial high-pressure high-temperature (HPHT) FNDs. We find that on average, the relative contribution of the NV- charge state to the total NV PL is lower and the NV PL lifetime is longer in CVD FNDs compared to HPHT FNDs, both likely due to the lower Ns0 concentration in CVD FNDs. The CVD bulk and CVD FNDs on average show similar average T1 spin relaxation times of 3.2 $ \pm$ 0.7 ms and 4.7 $ \pm$ 1.6 ms, respectively, compared to 0.17 $ \pm$ 0.01 ms for commercial HPHT FNDs. Our results demonstrate that ball milling of CVD diamonds enables the large-scale fabrication of NV ensembles in FNDs with bulk-like T1 spin relaxation properties.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Uniform electron benchmark for the first-principles $GW_{0}$-Eliashberg theory
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-20 20:00 EDT
Ryosuke Akashi, Hiroshi Shinaoka
We investigate the numerical behavior of the Eliashberg equations for phonon-mediated superconductivity, incorporating normal-state self-energy calculations within the consistent $ GW_{0}$ approximation. We account for the full wavenumber and frequency dependences of both the screened Coulomb interaction and phonon-mediated attraction. We present results for the prototypical uniform electron gas system with model Einstein phonons at temperatures of a few kelvin. At extremely low temperatures, we efficiently execute the required convolutions of Green’s functions and interactions in Matsubara frequency and wavenumber using intermediate representation and Fourier convolution techniques. In particular, we elucidate the interplay between electron-phonon $ \omega$ -mass and $ k$ -mass renormalizations of the electronic self-energy in determining the normal-state effective mass, spectral weight and the superconducting transition temperature. The electron density regimes where the plasmon effect enhances or suppresses the phonon-mediated superconductivity on top of the static Coulomb effect are revealed. We compare our comprehensive Eliashberg calculation results with those from density functional theory for superconductors, where the functionals have been constructed with reference to Eliashberg theory. Our model, methods, and results provide a valuable benchmark for first-principles superconducting calculations that treat screened Coulomb interaction effects non-empirically.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
11 pages, 6 figures, 2 tables
Many-body theory of false vacuum decay in quantum spin chains
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-20 20:00 EDT
Christian Johansen, Alessio Recati, Iacopo Carusotto, Alberto Biella
In this work we theoretically investigate the false vacuum decay process in a ferromagnetic quantum spin-1/2 chain. We develop a many-body theory describing the nucleation and the coherent dynamics of true-vacuum bubbles that is analytically tractable and agrees with numerical matrix product state calculations in all parameter regimes up to intermediate times. This bosonic theory allows us to identify different regimes in the parameter space and unravel the underlying physical mechanisms. In particular, regimes that closely correspond to the cosmological false vacuum decay picture are highlighted and characterized in terms of observable quantities.
Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Lattice (hep-lat), High Energy Physics - Theory (hep-th), Quantum Physics (quant-ph)
Magnetic brightening of light-like excitons in a monolayer semiconductor
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-20 20:00 EDT
A. Delhomme, T. Amit, P. Ji, C. Faugeras, S. Refaely-Abramson, J.J. Finley, A.V. Stier
Monolayer transition-metal dichalcogenides, such as WSe$ _2$ , are direct gap, multi-valley semiconductors. Long-range electron-hole exchange interactions mix the valleys, yielding dispersion relations for massive ($ \propto Q^2$ ) as well as light-like ($ \propto Q$ ) excitons. We report magneto-photoluminescence spectroscopy of excitons in the monolayer semiconductor WSe$ _2$ to $ B = \pm25$ T. The magnetic field-dependent line shape of the neutral exciton reveals the emergence of a new blue-detuned emission peak in both field orientations. Analyzing the distinct magnetic field-dependent shifts of both peaks facilitates the identification of the emergent feature as a spin-singlet with a significantly smaller reduced exciton mass as compared to the neutral exciton. The intensity of the emergent feature increases with magnetic field according to $ \propto B^2$ , as expected for a linear dispersion relation. The density-dependent diamagnetic shift ratios of both features follow the expected density dependence of the electron-hole exchange interactions. We interpret our observations within a picture of magnetic-field-induced coupling between the bright massive and quasi dark light-like exciton, leading to its brightening.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Random cubic graph embedded in a hypercube: Entanglement spectrum and many-body localization
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-20 20:00 EDT
The schematic model of interacting spins is introduced, which combines the symmetry of hypercube with the simplicity of random regular graph with degree three, i.e. the random cubic graph. We study the localization transition in this model, which shares essential characteristics with the systems exhibiting many-body localization. Namely, we investigate the transition in terms of the entanglement entropy and entanglement spectrum. We also show that the most significant indicator of the localization transition is the failure of eigenstate thermalization hypothesis, when the distribution of matrix elements of local operators changes from Gasussian to bimodal. It also provides good estimate for the critical disorder strength.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn)
21 pages, 21 figures
Phys. Rev. B 112, 024205 (2025)
Large-scale cooperative sulfur vacancy dynamics in two-dimensional MoS2 from machine learning interatomic potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Aaron Flötotto, Benjamin Spetzler, Rose von Stackelberg, Martin Ziegler, Erich Runge, Christian Dreßler
The formation of extended sulfur vacancies in MoS2 monolayers is closely associated with catalytic activity and may also be the basis for its memristive behavior. Nanosecond-scale molecular dynamics simulations using machine learning interatomic potentials (MLIPs) reveal key mechanisms of cooperative vacancy transport, including incorporation of vacancies into clusters of arbitrary size. The simulations provide a coherent atomistic explanation for irradiation-induced vacancy patterns observed experimentally, especially the formation of line defects spanning tens of nanometers. Results and performance are compared of two MLIP frameworks: (i) on-the-fly learning with Gaussian approximation potential, and (ii) fine-tuning of an equivariant foundation model.
Materials Science (cond-mat.mtrl-sci)
17 pages, 9 figures
Elementary Monte Carlo model of the anisotropic recrystallization and antiripening under intensive stirring and high supersaturations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Serhii Abakumov, Eugen Rabkin, Andriy Gusak
Known method of fibrous oxides production (first of all, V2O5) by intensive stirring in water is treated in the frame of driven systems approach developed in 80s by Georges Martin et al for systems under irradiation or severe plastic deformation. Instead of ballistic diffusion, the ballistic detachments of atoms from the oxide surface under stirring are introduced. Simplified Monte Carlo scheme is suggested for crystal evolution within TLK model, taking into account anisotropy and additional athermal detachment probabilities. Individual cluster in limited volume becomes elongated in steady-state or dissolve. For the ensemble of clusters, the number is decreasing (as in common ripening), but the mean length of fibers grows, as well as the total surface energy (contrary to common ripening).
Materials Science (cond-mat.mtrl-sci)
18 pages, 11 figures
Extraction of the self energy and Eliashberg function from angle resolved photoemission spectroscopy using the \textsc{xARPES} code
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Thomas P. van Waas, Christophe Berthod, Jan Berges, Nicola Marzari, J. Hugo Dil, Samuel Poncé
Angle-resolved photoemission spectroscopy is a powerful experimental technique for studying anisotropic many-body interactions through the electron spectral function. Existing attempts to decompose the spectral function into non-interacting dispersions and electron-phonon, electron-electron, and electron-impurity self-energies rely on linearization of the bands and manual assignment of self-energy magnitudes. Here, we show how self-energies can be extracted consistently for curved dispersions. We extend the maximum-entropy method to Eliashberg-function extraction with Bayesian inference, optimizing the parameters describing the dispersions and the magnitudes of electron-electron and electron-impurity interactions. We compare these novel methodologies with state-of-the-art approaches on model data, then demonstrate their applicability with two high-quality experimental data sets. With the first set, we identify the phonon modes of a two-dimensional electron liquid on TiO$ _2$ -terminated SrTiO$ _3$ . With the second set, we obtain unprecedented agreement between two Eliashberg functions of Li-doped graphene extracted from separate dispersions. We release these functionalities in the novel Python code \textsc{xARPES}.
Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con), Computational Physics (physics.comp-ph)
10 pages, 7 figures
Atomistic mechanisms of phase transitions in all-temperature barocaloric material KPF$_6$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Jiantao Wang, Yi-Chi Zhang, Yan Liu, Hongkun Deng, Mingfeng Liu, Yan Sun, Bing Li, Xing-Qiu Chen, Peitao Liu
Conventional barocaloric materials typically exhibit limited operating temperature ranges. In contrast, KPF$ _6$ has recently been reported to achieve an exceptional all-temperature barocaloric effect (BCE) via pressure-driven phase transitions. Here, we elucidate the atomistic mechanisms underlying the phase transitions through first-principles calculations and machine-learning potential accelerated molecular dynamics simulations. We identify four distinct phases: the room-temperature cubic (C) plastic crystal characterized by strong fluorine orientational disorder (FOD) and anharmonicity, the intermediate-temperature monoclinic (M-II) phase with decreasing FOD, the low-temperature monoclinic (M-I) phase with suppressed FOD, and the fully ordered rhombohedral (R) phase under pressure. Phonon calculations confirm the dynamic stability of the M-II, M-I, and R phases at 0 K, whereas the C phase requires thermal fluctuations for stabilization. Under pressure, all the C, M-II, and M-I phases transform to the R phase, which are driven by cooperative PF$ _6$ octahedral rotations coupled with lattice modulations. These pressure-induced phase transitions result in persistent isothermal entropy changes across a wide temperature range, thereby explaining the experimentally observed all-temperature BCE in this material. Hybrid functional calculations reveal wide-bandgap insulating behavior across all phases. This work deciphers the interplay between FOD, anharmonicity, and phase transitions in KPF$ _6$ , providing important insights for the design of BCE materials with broad operational temperature spans.
Materials Science (cond-mat.mtrl-sci)
16 pages, 15 figures, 4 tables (including Supplemental Material)
Phase Separation Kinetics in a Polar Active Field Model
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-20 20:00 EDT
Massimiliano Semeraro, Leticia F. Cugliandolo, Giuseppe Gonnella, Adriano Tiribocchi
A milestone of phase separation kinetics is the emergence of universal power laws $ \sim t^{1/z}$ governing the domain growth evolution. We investigate a phase-separating polar active model comprising a scalar density field with an advective coupling to a polarization field. Our analysis reveals a novel $ \sim t^{0.6}$ regime, which agrees well with the accelerated growth recently observed in simulations of polar active particles. We provide analytical arguments to explain how advection facilitates the creation of topological defects and compresses the domains leading to faster growth. We also show that the $ \sim t^{0.6}$ regime is robust to several model generalizations.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Main document with 6 pages 4 figures, Supplemental Material with 27 pages and 20 figures, 8 Movies
Order-Disorder Transitions and Thermal Pathways in Frustrated 2D Colloidal Crystals
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-20 20:00 EDT
Alexandre Vargas, Thiago Puccinelli, José Rafael Bordin
We employ extensive NPT molecular dynamics simulations to explore the thermal transitions of two-dimensional colloidal crystals interacting via a core-softened potential with competing length scales. The system stabilizes three distinct solid phases, namely low-density triangular (LDT), stripe, and kagome, which exhibit markedly different responses to heating and cooling. Our simulations reveal that the LDT and kagome phases melt via first-order transitions, but only the former recrystallizes smoothly. The kagome phase displays strong hysteresis and metastability, while the stripe phase undergoes a continuous and nearly reversible transformation. These results highlight the role of lattice geometry and frustration in shaping non-universal melting and freezing pathways in 2D soft matter.
Soft Condensed Matter (cond-mat.soft)
Observation of relativistic domain wall motion in amorphous ferrimagnets
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Pietro Diona, Luca Maranzana, Sergey Artyukhin, Giacomo Sala
Domain walls in magnetic materials are sine-Gordon solitons characterized by relativistic kinematics, with the maximum spin-wave group velocity setting a limit for the domain wall speed and hence the highest operation frequency of magnetic devices. This relativistic regime has been observed only in crystalline iron-garnet ferrimagnets but is in general expected in many magnetic materials. In particular, amorphous rare-earth – transition metal ferrimagnets should exhibit relativistic effects because of their ultrafast magnetic dynamics. However, no evidence for these effects has been reported in these technologically relevant materials. Here, we show that the relativistic regime can be attained in easy-to-engineer amorphous ferrimagnetic alloys. In GdFeCo we observe a saturation of the current-induced domain wall velocity that is indicative of a maximum spin-wave speed of the order of 2 km/s. Our observations indicate that relativistic dynamics are not exclusive to ferrimagnetic garnets but also exist in rare-earth – transition-metal ferrimagnets, which provide a robust material platform for future magnetic devices operating at the ultimate speed limit.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Piezomagnetism-driven magnetoelectric coupling in altermagnetic multiferroic K3Cr2F7
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Ying Zhou, Hui-Min Zhang, Cheng-Ao Ji, Hongjun Xiang, Shuai Dong, James M. Rondinelli, Xue-Zeng Lu
Ferroelectric control of altermagnetism in momentum space has been studied widely, while the control of magnetism in real space of altermagnets are still rare. We present a design rule to identify multiferroicity in n=2 Ruddlesden-Popper halides. Our results show that a Jahn-Teller distortion can cooperate with oxygen octahedral rotations to break inversion symmetry, which we demonstrate in K3Cr2F7 and cation-ordered KAg2Cu2Cl7, and leads to a ferrielectric-to-ferroelectric phase transition in K3Cr2F7. Altermagnetic spin order in the ferrielectric phase of K3Cr2F7 transforms into a conventional antiferromagnetic order in the ferroelectric phase, at which strain/pressure engineered sizable changes of weak ferromagnetism can occur. Our study is not only conducive to realize strong magnetoelectric coupling in multiferroics, but also reveals more functionalities in altermagnetic materials.
Materials Science (cond-mat.mtrl-sci)
A first-principles theoretical study on two-dimensional MX and MX$_2$ metal halides: bandgap engineering, magnetism, and catalytic descriptors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-20 20:00 EDT
Yu-Hsiu Lin, Daniel Maldonado-Lopez, Jose L. Mendoza-Cortes
Metal halides, particularly MX and MX$ _2$ compounds (where M represents metal elements and X = F, Cl, Br, I), have attracted significant interest due to their diverse electronic and optoelectronic properties. However, a comprehensive understanding of their structural and electronic behavior, particularly the evolution of these properties from bulk to low-dimensional forms, remains limited. To address this gap, we performed first-principles calculations to develop a database of 60 MX and MX$ _2$ metal halides, detailing their structural and electronic properties in both bulk and slab configurations. Calculations were performed using the advanced \texttt{HSE06-D3} hybrid functional for density functional theory (DFT), ensuring high precision in predicting material properties despite the associated computational cost. The results reveal that these materials are predominantly semiconductors, but their bandgaps range from 0 to 9 eV. A detailed analysis of the transition from bulk to slab structures highlights notable shifts in electronic properties, including bandgap modifications. Upon dimensional reduction, 9 materials exhibit an indirect-to-direct bandgap transition, enhancing their potential for energy conversion. Beyond structural dimensionality, the influence of chemical composition on bandgap variations was also examined. To further assess their practical applicability, the catalytic and magnetic properties of these metal halides were systematically evaluated. These findings not only illuminate previously underexplored MX and MX$ _2$ metal halides but also identify promising candidates for electronic, optoelectronic, catalytic and spintronic applications. This database serves as a valuable resource for guiding future research and technology development in low-dimensional materials.
Materials Science (cond-mat.mtrl-sci)
Originality of resonance and locking phenomena in $φ_{0}$ junction
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-20 20:00 EDT
We demonstrate the realization and interplay of two ferromagnetic resonances in the SFS $ \varphi_0$ Josephson junction. One of the resonances that is realized under microwave radiation is the famous Kittel ferromagnetic resonance. The other is the Buzdin ferromagnetic resonance appearing as a result of interaction of superconducting current and ferromagnetic interlayer magnetization. Transformations of one type of resonance to another under variation in the parameters of external radiation and the parameters of the $ \varphi_0$ junction open the way to manipulation of the features of ferromagnetic resonances. The combined ferromagnetic resonance that exhibits the features of both resonances is demonstrated too. The 2D-diagrams $ \omega_R-I$ for the maximal magnetization component $ m_y$ have an interesting intersection points of the Kittel and Buzdin resonances, where the value of $ m^{max}_y$ is strongly increased. The obtained results demonstrate reach physics and unique opportunities for various applications.
Superconductivity (cond-mat.supr-con)
7 pages, 5 figures
Electrochemical response of biological membranes to localized currents and external electric fields
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-20 20:00 EDT
Joshua B. Fernandes, Hyeongjoo Row, Kranthi K. Mandadapu, Karthik Shekhar
Electrochemical phenomena in biology often unfold in confined geometries where micrometer- to millimeter-scale domains coexist with nanometer-scale interfacial diffuse charge layers. We analyze a model lipid membrane-electrolyte system where an ion channel-like current flows across the membrane while parallel electrodes simultaneously apply a step voltage, emulating an extrinsic electric field. Matched asymptotic expansions of the Poisson-Nernst-Planck equations show that, under physiological conditions, the diffuse charge layers rapidly reach a quasi-steady state, and the bulk electrolyte remains electroneutral. As a result, all free charge is confined to the nanometer-scale screening layers at the membrane and electrode interfaces. The bulk electric potential satisfies Laplace’s equation, and is dynamically coupled to the interfacial layers through time-dependent boundary conditions. This multiscale coupling partitions the space-time response into distinct regimes. At sufficiently long times, we show that the system can be represented by an equivalent circuit analogous to those used in classical cable theory. We derive closed-form expressions of the transmembrane potential within each regime, and verify them against nonlinear numerical simulations. Our results show how electrode-induced screening and confinement effects influence the electrochemical response over multiple length and time scales in biological systems.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph), Subcellular Processes (q-bio.SC)
16 pages, 10 figures
Machine Learning H-theorem
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-20 20:00 EDT
H-theorem provides a microscopic foundation of the Second Law of Thermodynamics and is therefore essential to establishing statistical physics, but at the same time, H-theorem has been subject to controversy that in part persists till this day. To better understand H-theorem and its relation to the arrow of time, we study the equilibration of randomly oriented and positioned hard disks with periodic boundary conditions. Using a model based on the DeepSets architecture, which imposes permutation invariance of the particle labels, we train a model to capture the irreversibility of the H-functional.
Statistical Mechanics (cond-mat.stat-mech), Machine Learning (cs.LG)
Photoinduced Frustration Modulation in $κ$-type Quantum Spin Liquid Candidates
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-20 20:00 EDT
M. Tepie, F. Glerean, J. Ovčar, S. Priya, K. Miyagawa, H. Taniguchi, K. Kanoda, I. Lončarić, M. Dressel, M. Mitrano
Geometric frustration is a key parameter controlling electronic and magnetic properties of quantum spin liquid systems, yet remains challenging to tune. Here, we coherently drive molecular vibrations with midinfrared pulses in two organic quantum spin liquid candidates, the insulating $ \kappa$ -(BEDT-TTF)$ _2$ Cu$ _2$ (CN)$ _3$ and the metallic $ \kappa$ -(BEDT-TTF)$ _4$ Hg$ _{2.89}$ Br$ _8$ , and probe their electronic response through ultrafast reflectivity measurements. We observe a nonlinear coupling between local molecular vibrations and nonlocal phonons, which is expected to directly modulate the geometric frustration of their triangular lattice. Our findings establish a promising route to dynamically control frustration in nonbipartite quantum materials.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
17 pages, 13 figures