CMP Journal 2025-02-12

Statistics

Nature: 31

Nature Materials: 2

Physical Review Letters: 12

Physical Review X: 2

arXiv: 64

Nature

σ-Bond insertion reactions of two strained diradicaloids

Original Paper | Synthetic chemistry methodology | 2025-02-11 19:00 EST

Arismel Tena Meza, Christina A. Rivera, Huiling Shao, Andrew V. Kelleghan, K. N. Houk, Neil K. Garg

The development of new synthetic methodologies are instrumental for enabling the discovery of new medicines. Those methods that provide efficient access to structural alternatives for aromatic compounds (i.e., saturated arene bioisosteres), have become highly coveted.^1,2,3,4 The incorporation of such bioisosteres typically leads to favorable drug-like properties and represents an emerging field of research. Here, we report a new synthetic method that furnishes one especially coveted motif, the bicyclo[2.1.1]hexane scaffold,^5,6 using mild reaction conditions and an operationally-simple protocol. The methodology proceeds via the uncommon coupling of two strained fragments: transiently-generated cyclic allenes and bicyclo[1.1.0]butanes, which possess considerable strain energies of ~30 kcal/mol⁷ and ~60 kcal/mol,⁶ respectively. The reaction is thought to proceed via a σ-bond insertion through a diradical pathway. However, rather than requiring an external stimulus to generate radical species, reactivity is thought to arise as a result of innate diradical character present in each reactant. This diradicaloid character,⁸ an underutilized parameter in reaction design, arises from the severe geometric distortions of each reactant. Our studies provide a means to access functionalized bicyclo[2.1.1]hexanes of value for drug discovery, underscore how geometric distortion of reactants can be used to enable uncommon modes of reactivity, and should encourage the further exploration and strategic use of diradicaloids in chemical synthesis.

Nature (2025)

Synthetic chemistry methodology, Organic chemistry, Reaction mechanisms

Observation of Plastic Ice VII by Quasi-Elastic Neutron Scattering

Original Paper | Chemical physics | 2025-02-11 19:00 EST

Maria Rescigno, Alberto Toffano, Umbertoluca Ranieri, Leon Andriambariarijaona, Richard Gaal, Stefan Klotz, Michael Marek Koza, Jacques Ollivier, Fausto Martelli, John Russo, Francesco Sciortino, Jose Teixeira, Livia Eleonora Bove

Water is the third most abundant molecule in the universe and a key component in the interiors of icy moons, giant planets, and Uranus- and Neptune-like exoplanets^1-3. Owing to its distinct molecular structure and flexible hydrogen bonds that readily adapt to a wide range of pressures and temperatures, water forms numerous crystalline and amorphous phases^4-6. Most relevant for the high pressures and temperatures of planetary interiors is ice VII⁴, and simulations have identified along its melting curve the existence of a so-called plastic phase^7-12 where individual molecules occupy fixed positions as in a solid yet are able to rotate as in a liquid. Such plastic ice has not yet been directly observed in experiments. Here, we present quasi-elastic neutron scattering (QENS) measurements, conducted at temperatures between 450 and 600 K and pressures up to 6 GPa, that reveal the existence of a body centered cubic (bcc) structure, as found in ice VII, with water molecules exhibiting picosecond rotational dynamics typical for liquid water. Comparison with molecular dynamics simulations indicates that this plastic ice VII does not conform to a free rotor phase but rather exhibits rapid orientational jumps, as observed in jump-rotor plastic crystals^13,14. We anticipate that our observation of plastic ice VII will impact our understanding of the geodynamics of icy planets and the differentiation processes of large icy moons.

Nature (2025)

Chemical physics, Structure of solids and liquids

Observation of an ultra-high-energy cosmic neutrino with KM3NeT

Original Paper | High-energy astrophysics | 2025-02-11 19:00 EST

S. Aiello, A. Albert, A. R. Alhebsi, M. Alshamsi, S. Alves Garre, A. Ambrosone, F. Ameli, M. Andre, M. Anghinolfi, L. Aphecetche, M. Ardid, S. Ardid, C. Argüelles, H. Atmani, J. Aublin, F. Badaracco, L. Bailly-Salins, Z. Bardačová, B. Baret, A. Bariego-Quintana, Y. Becherini, M. Bendahman, F. Benfenati Gualandi, M. Benhassi, M. Bennani, D. M. Benoit, E. Berbee, V. Bertin, S. Biagi, M. Boettcher, D. Bonanno, A. B. Bouasla, J. Boumaaza, M. Bouta, M. Bouwhuis, C. Bozza, R. M. Bozza, H. Brânzaş, F. Bretaudeau, M. Breuhaus, R. Bruijn, J. Brunner, R. Bruno, E. Buis, R. Buompane, S. Buson, J. Busto, B. Caiffi, D. Calvo, A. Capone, F. Carenini, V. Carretero, T. Cartraud, P. Castaldi, V. Cecchini, S. Celli, L. Cerisy, M. Chabab, A. Chen, S. Cherubini, T. Chiarusi, M. Circella, R. Cocimano, J. A. B. Coelho, A. Coleiro, S. Colonges, A. Condorelli, R. Coniglione, P. Coyle, A. Creusot, G. Cuttone, A. D'Amico, R. Dallier, A. De Benedittis, B. De Martino, G. De Wasseige, V. Decoene, I. Del Rosso, L. S. Di Mauro, I. Di Palma, A. F. Diaz, D. Diego-Tortosa, C. Distefano, A. Domi, C. Donzaud, D. Dornic, E. Drakopoulou, D. Drouhin, J.-G. Ducoin, R. Dvornický, T. Eberl, E. Eckerová, A. Eddymaoui, T. van Eeden, M. Eff, D. van Eijk, I. El Bojaddaini, S. El Hedri, V. Ellajosyula, A. Enzenhöfer, G. Ferrara, M. D. Filipovićv, F. Filippini, D. Franciotti, L. A. Fusco, S. Gagliardini, T. Gal, J. García Méndez, A. Garcia Soto, C. Gatius Oliver, N. Geißelbrecht, E. Genton, H. Ghaddari, L. Gialanella, B. K. Gibson, E. Giorgio, I. Goos, P. Goswami, S. R. Gozzini, R. Gracia, K. Graf, C. Guidi, B. Guillon, M. Gutiérrez, C. Haack, H. van Haren, A. Heijboer, L. Hennig, S. Henry, J. J. Hernández-Rey, W. Idrissi Ibnsalih, A. Ilioni, G. Illuminati, D. Joly, M. de Jong, P. de Jong, B. J. Jung, P. Kalaczyński, O. Kalekin, N. Kamp, U. F. Katz, G. Kistauri, C. Kopper, A. Kouchner, Y. Y. Kovalev, V. Kueviakoe, V. Kulikovskiy, R. Kvatadze, M. Labalme, R. Lahmann, M. Lamoureux, S. Lancelin, G. Larosa, C. Lastoria, J. Lazar, A. Lazo, S. Le Stum, G. Lehaut, V. Lemaitre, E. Leonora, N. Lessing, G. Levi, M. Lincetto, M. Lindsey Clark, F. Longhitano, N. Lumb, F. Magnani, J. Majumdar, L. Malerba, F. Mamedov, A. Manfreda, M. Marconi, A. Margiotta, A. Marinelli, C. Markou, L. Martin, F. Marzaioli, M. Mastrodicasa, S. Mastroianni, J. Mauro, G. Miele, P. Migliozzi, E. Migneco, M. L. Mitsou, C. M. Mollo, M. Mongelli, L. Morales-Gallegos, A. Moussa, I. Mozun Mateo, R. Muller, M. R. Musone, M. Musumeci, S. Navas, A. Nayerhoda, C. A. Nicolau, B. Nkosi, B. Ó Fearraigh, V. Oliviero, A. Orlando, E. Oukacha, D. Paesani, J. Palacios González, G. Papalashvili, C. Paries, V. Parisi, E. J. Pastor Gomez, C. Pastore, A. M. Păun, G. E. Păvălaş, S. Peña Martínez, M. Perrin-Terrin, V. Pestel, R. Pestes, L. Pfeiffer, P. Piattelli, A. Plavin, C. Poirè, V. Popa, T. Pradier, J. Prado, S. Pulvirenti, C. A. Quiroz-Rangel, N. Randazzo, S. Razzaque, I. C. Rea, D. Real, G. Riccobene, J. Robinson, A. Romanov, E. Ros, A. Šaina, F. Salesa Greus, D. F. E. Samtleben, A. Sánchez Losa, S. Sanfilippo, M. Sanguineti, D. Santonocito, P. Sapienza, J. Schmelling, J. Schnabel, J. Schumann, H. M. Schutte, J. Seneca, N. Sennan, P. Sevle, I. Sgura, R. Shanidze, A. Sharma, Y. Shitov, F. Šimkovic, A. Simonelli, A. Sinopoulou, B. Spisso, M. Spurio, D. Stavropoulos, I. Štekl, M. Taiuti, Y. Tayalati, H. Thiersen, S. Thoudam, I. Tosta e Melo, B. Trocmé, V. Tsourapis, A. Tudorache, E. Tzamariudaki, A. Ukleja, A. Vacheret, V. Valsecchi, V. Van Elewyck, G. Vannoye, G. Vasileiadis, F. Vazquez de Sola, C. Verilhac, A. Veutro, S. Viola, D. Vivolo, A. van Vliet, A. Y. Wen, E. de Wolf, I. Lhenry-Yvon, S. Zavatarelli, A. Zegarelli, D. Zito, J. D. Zornoza, J. Zúñiga, N. Zywucka

The detection of cosmic neutrinos with energies above a teraelectronvolt (TeV) offers a unique exploration into astrophysical phenomena^1,2,3. Electrically neutral and interacting only by means of the weak interaction, neutrinos are not deflected by magnetic fields and are rarely absorbed by interstellar matter: their direction indicates that their cosmic origin might be from the farthest reaches of the Universe. High-energy neutrinos can be produced when ultra-relativistic cosmic-ray protons or nuclei interact with other matter or photons, and their observation could be a signature of these processes. Here we report an exceptionally high-energy event observed by KM3NeT, the deep-sea neutrino telescope in the Mediterranean Sea⁴, which we associate with a cosmic neutrino detection. We detect a muon with an estimated energy of \(12{0}_{-60}^{+110}\) petaelectronvolts (PeV). In light of its enormous energy and near-horizontal direction, the muon most probably originated from the interaction of a neutrino of even higher energy in the vicinity of the detector. The cosmic neutrino energy spectrum measured up to now^5,6,7 falls steeply with energy. However, the energy of this event is much larger than that of any neutrino detected so far. This suggests that the neutrino may have originated in a different cosmic accelerator than the lower-energy neutrinos, or this may be the first detection of a cosmogenic neutrino⁸, resulting from the interactions of ultra-high-energy cosmic rays with background photons in the Universe.

Nature 638, 376-382 (2025)

High-energy astrophysics, Particle astrophysics

Learning produces an orthogonalized state machine in the hippocampus

Original Paper | Learning algorithms | 2025-02-11 19:00 EST

Weinan Sun, Johan Winnubst, Maanasa Natrajan, Chongxi Lai, Koichiro Kajikawa, Arco Bast, Michalis Michaelos, Rachel Gattoni, Carsen Stringer, Daniel Flickinger, James E. Fitzgerald, Nelson Spruston

Cognitive maps confer animals with flexible intelligence by representing spatial, temporal and abstract relationships that can be used to shape thought, planning and behaviour. Cognitive maps have been observed in the hippocampus¹, but their algorithmic form and learning mechanisms remain obscure. Here we used large-scale, longitudinal two-photon calcium imaging to record activity from thousands of neurons in the CA1 region of the hippocampus while mice learned to efficiently collect rewards from two subtly different linear tracks in virtual reality. Throughout learning, both animal behaviour and hippocampal neural activity progressed through multiple stages, gradually revealing improved task representation that mirrored improved behavioural efficiency. The learning process involved progressive decorrelations in initially similar hippocampal neural activity within and across tracks, ultimately resulting in orthogonalized representations resembling a state machine capturing the inherent structure of the task. This decorrelation process was driven by individual neurons acquiring task-state-specific responses (that is, ‘state cells'). Although various standard artificial neural networks did not naturally capture these dynamics, the clone-structured causal graph, a hidden Markov model variant, uniquely reproduced both the final orthogonalized states and the learning trajectory seen in animals. The observed cellular and population dynamics constrain the mechanisms underlying cognitive map formation in the hippocampus, pointing to hidden state inference as a fundamental computational principle, with implications for both biological and artificial intelligence.

Nature (2025)

Learning algorithms, Learning and memory

Transcriptional adaptation upregulates utrophin in Duchenne muscular dystrophy

Original Paper | Experimental models of disease | 2025-02-11 19:00 EST

Lara Falcucci, Christopher M. Dooley, Douglas Adamoski, Thomas Juan, Justin Martinez, Angelina M. Georgieva, Kamel Mamchaoui, Cansu Cirzi, Didier Y. R. Stainier

Duchenne muscular dystrophy (DMD) is a muscle-degenerating disease caused by mutations in the DMD gene, which encodes the dystrophin protein^1,2. Utrophin (UTRN), the genetic and functional paralogue of DMD, is upregulated in some DMD patients^3,4,5. To further investigate this UTRN upregulation, we first developed an inducible messenger RNA (mRNA) degradation system for DMD by introducing a premature termination codon (PTC) in one of its alternatively spliced exons. Inclusion of the PTC-containing exon triggers DMD mutant mRNA decay and UTRN upregulation. Notably, blocking nonsense-mediated mRNA decay results in the reversal of UTRN upregulation, whereas overexpressing DMD does not. Furthermore, overexpressing DMD^PTC minigenes in wild-type cells causes UTRN upregulation, as does a wild-type DMD minigene containing a self-cleaving ribozyme. To place these findings in a therapeutic context, we used splice-switching antisense oligonucleotides (ASOs) to induce the skipping of out-of-frame exons of DMD, aiming to introduce PTCs. We found that these ASOs cause UTRN upregulation. In addition, when using an ASO to restore the DMD reading frame in myotubes derived from a DMD^ΔE52 patient, an actual DMD treatment, UTRN upregulation was reduced. Altogether, these results indicate that an mRNA decay-based mechanism called transcriptional adaptation^6,7,8 plays a key role in UTRN upregulation in DMD^PTC patients, and they highlight an unexplored therapeutic application of ASOs, as well as ribozymes, in inducing genetic compensation via transcriptional adaptation.

Nature (2025)

Experimental models of disease, Gene regulation, Genetics research, RNA splicing, Transcription

Transcriptomic neuron types vary topographically in function and morphology

Original Paper | Neural circuits | 2025-02-11 19:00 EST

Inbal Shainer, Johannes M. Kappel, Eva Laurell, Joseph C. Donovan, Martin W. Schneider, Enrico Kuehn, Irene Arnold-Ammer, Manuel Stemmer, Johannes Larsch, Herwig Baier

Neuronal phenotypic traits such as morphology, connectivity and function are dictated, to a large extent, by a specific combination of differentially expressed genes. Clusters of neurons in transcriptomic space correspond to distinct cell types and in some cases--for example, Caenorhabditis elegans neurons¹ and retinal ganglion cells^2,3,4--have been shown to share morphology and function. The zebrafish optic tectum is composed of a spatial array of neurons that transforms visual inputs into motor outputs. Although the visuotopic map is continuous, subregions of the tectum are functionally specialized^5,6. Here, to uncover the cell-type architecture of the tectum, we transcriptionally profiled its neurons, revealing more than 60 cell types that are organized in distinct anatomical layers. We measured the visual responses of thousands of tectal neurons by two-photon calcium imaging and matched them with their transcriptional profiles. Furthermore, we characterized the morphologies of transcriptionally identified neurons using specific transgenic lines. Notably, we found that neurons that are transcriptionally similar can diverge in shape, connectivity and visual responses. Incorporating the spatial coordinates of neurons within the tectal volume revealed functionally and morphologically defined anatomical subclusters within individual transcriptomic clusters. Our findings demonstrate that extrinsic, position-dependent factors expand the phenotypic repertoire of genetically similar neurons.

Nature (2025)

Neural circuits, Sensorimotor processing

Topological segregation of stress sensors along the gut crypt-villus axis

Original Paper | Neurophysiology | 2025-02-11 19:00 EST

Kouki K. Touhara, Nathan D. Rossen, Fei Deng, Joel Castro, Andrea M. Harrington, Tifany Chu, Sonia Garcia-Caraballo, Mariana Brizuela, Tracey O'Donnell, Jinhao Xu, Onur Cil, Stuart M. Brierley, Yulong Li, David Julius

The crypt-villus structure of the small intestine serves as an essential protective barrier. The integrity of this barrier is monitored by the complex sensory system of the gut, in which serotonergic enterochromaffin (EC) cells play an important part^1,2. These rare sensory epithelial cells surveil the mucosal environment for luminal stimuli and transmit signals both within and outside the gut^3,4,5,6. However, whether EC cells in crypts and villi detect different stimuli or produce distinct physiological responses is unknown. Here we address these questions by developing a reporter mouse model to quantitatively measure the release and propagation of serotonin from EC cells in live intestines. Crypt EC cells exhibit a tonic low-level mode that activates epithelial serotonin 5-HT₄ receptors to modulate basal ion secretion and a stimulus-induced high-level mode that activates 5-HT₃ receptors on sensory nerve fibres. Both these modes can be initiated by the irritant receptor TRPA1, which is confined to crypt EC cells. The activation of TRPA1 by luminal irritants is enhanced when the protective mucus layer is compromised. Villus EC cells also signal damage through a distinct mechanism, whereby oxidative stress activates TRPM2 channels, which leads to the release of both serotonin and ATP and consequent excitation of sensory nerve fibres. This topological segregation of EC cell functionality along the mucosal architecture constitutes a mechanism for the surveillance, maintenance and protection of gut integrity under diverse physiological conditions.

Nature (2025)

Neurophysiology, Somatosensory system

A metagenomic ‘dark matter' enzyme catalyses oxidative cellulose conversion

Original Paper | Enzyme mechanisms | 2025-02-11 19:00 EST

Clelton A. Santos, Mariana A. B. Morais, Fernanda Mandelli, Evandro A. Lima, Renan Y. Miyamoto, Paula M. R. Higasi, Evandro A. Araujo, Douglas A. A. Paixão, Joaquim M. Junior, Maria L. Motta, Rodrigo S. A. Streit, Luana G. Morão, Claudio B. C. Silva, Lucia D. Wolf, Cesar R. F. Terrasan, Nathalia R. Bulka, Jose A. Diogo, Felipe J. Fuzita, Felippe M. Colombari, Camila R. Santos, Priscila T. Rodrigues, Daiane B. Silva, Sacha Grisel, Juliana S. Bernardes, Nicolas Terrapon, Vincent Lombard, Antonio J. C. Filho, Bernard Henrissat, Bastien Bissaro, Jean-Guy Berrin, Gabriela F. Persinoti, Mario T. Murakami

The breakdown of cellulose is one of the most important reactions in nature^1,2 and is central to biomass conversion to fuels and chemicals³. However, the microfibrillar organization of cellulose and its complex interactions with other components of the plant cell wall poses a major challenge for enzymatic conversion⁴. Here, by mining the metagenomic ‘dark matter' (unclassified DNA with unknown function) of a microbial community specialized in lignocellulose degradation, we discovered a metalloenzyme that oxidatively cleaves cellulose. This metalloenzyme acts on cellulose through an exo-type mechanism with C1 regioselectivity, resulting exclusively in cellobionic acid as a product. The crystal structure reveals a catalytic copper buried in a compact jelly-roll scaffold that features a flattened cellulose binding site. This metalloenzyme exhibits a homodimeric configuration that enables in situ hydrogen peroxide generation by one subunit while the other is productively interacting with cellulose. The secretome of an engineered strain of the fungus Trichoderma reesei expressing this metalloenzyme boosted the glucose release from pretreated lignocellulosic biomass under industrially relevant conditions, demonstrating its biotechnological potential. This discovery modifies the current understanding of bacterial redox enzymatic systems devoted to overcoming biomass recalcitrance^5,6,7. Furthermore, it enables the conversion of agro-industrial residues into value-added bioproducts, thereby contributing to the transition to a sustainable and bio-based economy.

Nature (2025)

Enzyme mechanisms, Industrial microbiology

UM171 glues asymmetric CRL3-HDAC1/2 assembly to degrade CoREST corepressors

Original Paper | Cryoelectron microscopy | 2025-02-11 19:00 EST

Megan J. R. Yeo, Olivia Zhang, Xiaowen Xie, Eunju Nam, N. Connor Payne, Pallavi M. Gosavi, Hui Si Kwok, Irtiza Iram, Ceejay Lee, Jiaming Li, Nicholas J. Chen, Khanh Nguyen, Hanjie Jiang, Zhipeng A. Wang, Kwangwoon Lee, Haibin Mao, Stefan A. Harry, Idris A. Barakat, Mariko Takahashi, Amanda L. Waterbury, Marco Barone, Andrea Mattevi, Steven A. Carr, Namrata D. Udeshi, Liron Bar-Peled, Philip A. Cole, Ralph Mazitschek, Brian B. Liau, Ning Zheng

UM171 is a potent agonist of ex vivo human haematopoietic stem cell self-renewal¹. By co-opting KBTBD4, a substrate receptor of the CUL3-RING E3 ubiquitin ligase (CRL3) complex, UM171 promotes the degradation of the LSD1-CoREST corepressor complex, thereby limiting haematopoietic stem cell attrition^2,3. However, the direct target and mechanism of action of UM171 remain unclear. Here we show that UM171 acts as a molecular glue to induce high-affinity interactions between KBTBD4 and HDAC1/2 to promote corepressor degradation. Through proteomics and chemical inhibitor studies, we identify the principal target of UM171 as HDAC1/2. Cryo-electron microscopy analysis of dimeric KBTBD4 bound to UM171 and the LSD1-HDAC1-CoREST complex identifies an asymmetric assembly in which a single UM171 molecule enables a pair of KELCH-repeat propeller domains to recruit the HDAC1 catalytic domain. One KBTBD4 propeller partially masks the rim of the HDAC1 active site, which is exploited by UM171 to extend the E3-neosubstrate interface. The other propeller cooperatively strengthens HDAC1 binding through a distinct interface. The overall CoREST-HDAC1/2-KBTBD4 interaction is further buttressed by the endogenous cofactor inositol hexakisphosphate, which acts as a second molecular glue. The functional relevance of the quaternary complex interaction surfaces is demonstrated by base editor scanning of KBTBD4 and HDAC1. By delineating the direct target of UM171 and its mechanism of action, we reveal how the cooperativity offered by a dimeric CRL3 E3 can be leveraged by a small molecule degrader.

Nature (2025)

Cryoelectron microscopy, Mechanism of action, Mutagenesis, Target identification

Global engineering effects of soil invertebrates on ecosystem functions

Original Paper | Biodiversity | 2025-02-11 19:00 EST

Donghao Wu, Enzai Du, Nico Eisenhauer, Jérome Mathieu, Chengjin Chu

The biogenic structures produced by termites, ants and earthworms provide key functions across global ecosystems^1,2. However, little is known about the drivers of the soil engineering effects caused by these small but important invertebrates³ at the global scale. Here we show, on the basis of a meta-analysis of 12,975 observations from 1,047 studies on six continents, that all three taxa increase soil macronutrient content, soil respiration and soil microbial and plant biomass compared with reference soils. The effect of termites on soil respiration and plant biomass, and the effect of earthworms on soil nitrogen and phosphorus content, increase with mean annual temperature and peak in the tropics. By contrast, the effects of ants on soil nitrogen, soil phosphorus, plant biomass and survival rate peak at mid-latitude ecosystems that have the lowest primary productivity. Notably, termites and ants increase plant growth by alleviating plant phosphorus limitation in the tropics and nitrogen limitation in temperate regions, respectively. Our study highlights the important roles of these invertebrate taxa in global biogeochemical cycles and ecosystem functions. Given the importance of these soil-engineering invertebrates, biogeochemical models should better integrate their effects, especially on carbon fluxes and nutrient cycles.

Nature (2025)

Biodiversity, Biogeography, Carbon cycle, Ecosystem ecology, Element cycles

Genetic architecture in Greenland is shaped by demography, structure and selection

Original Paper | Genetics research | 2025-02-11 19:00 EST

Frederik Filip Stæger, Mette K. Andersen, Zilong Li, Jasmin Pernille Hjerresen, Shixu He, Cindy G. Santander, Rasmus Tanderup Jensen, Karsten Fleischer Rex, Anne Cathrine Baun Thuesen, Kristian Hanghøj, Inge Høst Seiding, Emil Jørsboe, Sara Elizabeth Stinson, Malthe Sebro Rasmussen, Renzo F. Balboa, Christina Viskum Lytken Larsen, Peter Bjerregaard, Mikkel Schubert, Jonas Meisner, Allan Linneberg, Niels Grarup, Eleftheria Zeggini, Rasmus Nielsen, Marit E. Jørgensen, Torben Hansen, Ida Moltke, Anders Albrechtsen

Greenlandic Inuit and other indigenous populations are underrepresented in genetic research^1,2, leading to inequity in healthcare opportunities. To address this, we performed analyses of sequenced or imputed genomes of 5,996 Greenlanders with extensive phenotypes. We quantified their historical population bottleneck and how it has shaped their genetic architecture to have fewer, but more common, variable sites. Consequently, we find twice as many high-impact genome-wide associations to metabolic traits in Greenland compared with Europe. We infer that the high-impact variants arose after the population split from Native Americans and thus are Arctic-specific, and show that some of them are common due to not only genetic drift but also selection. We also find that European-derived polygenic scores for metabolic traits are only half as accurate in Greenlanders as in Europeans, and that adding Arctic-specific variants improves the overall accuracy to the same level as in Europeans. Similarly, lack of representation in public genetic databases makes genetic clinical screening harder in Greenlandic Inuit, but inclusion of Greenlandic data remedies this by reducing the number of non-causal candidate variants by sixfold. Finally, we identify pronounced genetic fine structure that explains differences in prevalence of monogenic diseases in Greenland and, together with recent changes in mobility, leads to a predicted future reduction in risk for certain recessive diseases. These results illustrate how including data from Greenlanders can greatly reduce inequity in genomic-based healthcare.

Nature (2025)

Genetics research, Genome-wide association studies, Medical genetics, Population genetics, Risk factors

Macrophages protect against sensory axon loss in peripheral neuropathy

Original Paper | Neuroimmunology | 2025-02-11 19:00 EST

Sara Hakim, Aakanksha Jain, Stuart S. Adamson, Veselina Petrova, Jonathan Indajang, Hyoung Woo Kim, Riki Kawaguchi, Qing Wang, Elif S. Duran, Drew Nelson, Caitlin A. Greene, Jenae Rasmussen, Clifford J. Woolf

Peripheral neuropathy is a common complication of type 2 diabetes, which is strongly associated with obesity¹, causing sensory loss and, in some patients, neuropathic pain^2,3. Although the onset and progression of diabetic peripheral neuropathy is linked with dyslipidaemia and hyperglycaemia⁴, the contribution of inflammation to peripheral neuropathy pathogenesis has not been investigated. Here we used a high-fat, high-fructose diet (HFHFD), which induces obesity and prediabetic metabolic changes, to study the onset of peripheral neuropathy. Mice fed the HFHFD developed persistent heat hypoalgesia after 3 months, but a reduction in epidermal skin nerve fibre density manifested only at 6 months. Using single-cell sequencing, we found that CCR2⁺ macrophages infiltrate the sciatic nerves of HFHFD-fed mice well before axonal degeneration is detectable. These infiltrating macrophages share gene expression similarities with nerve-crush-induced macrophages⁵ and express neurodegeneration-associated microglial marker genes⁶, although there is no axon loss or demyelination. Inhibiting the macrophage recruitment by genetically or pharmacologically blocking CCR2 signalling resulted in more severe heat hypoalgesia and accelerated skin denervation, as did deletion of Lgals3, a gene expressed in recruited macrophages. Recruitment of macrophages into the peripheral nerves of obese prediabetic mice is, therefore, neuroprotective, delaying terminal sensory axon degeneration by means of galectin 3. Potentiating and sustaining early neuroprotective immune responses in patients could slow or prevent peripheral neuropathy.

Nature (2025)

Neuroimmunology, Peripheral neuropathies

Manipulation of the altermagnetic order in CrSb via crystal symmetry

Original Paper | Electronic properties and materials | 2025-02-11 19:00 EST

Zhiyuan Zhou, Xingkai Cheng, Mengli Hu, Ruiyue Chu, Hua Bai, Lei Han, Junwei Liu, Feng Pan, Cheng Song

Crystal symmetry guides the development of condensed matter. The unique crystal symmetry connecting magnetic sublattices not only distinguishes altermagnetism^1,2,3,4,5,6 from ferromagnetism and conventional antiferromagnetism but also enables it to combine the advantages of ferromagnetism and antiferromagnetism^4,5. Altermagnetic order is essentially a magnetic crystal order⁷, determined by the magnetic-order (Néel) vector and crystal symmetry. Previous experimental studies have concentrated on manipulating the altermagnetic symmetry by tuning the Néel vector orientations^8,9,10,11,12. However, manipulation of the crystal symmetry, which holds great promise for manipulating the altermagnetic order, remains challenging. Here we realize the manipulation of altermagnetic order in chromium antimonide (CrSb) films via crystal symmetry. The locking between the Dzyaloshinskii-Moriya vector and the magnetic space symmetry helps to reconstruct the altermagnetic order, from a collinear Néel vector to a canted one. It generates a room-temperature spontaneous anomalous Hall effect in an altermagnet. The relative direction between the current-induced spin polarization and the Dzyaloshinskii-Moriya vector determines the switching modes of altermagnetic order, that is, parallel for the field-assisted mode in CrSb\((1\bar{1}00)\)/Pt and non-parallel for the field-free mode in W/CrSb\((11\bar{2}0)\). The Dzyaloshinskii-Moriya vector induces an asymmetric energy barrier in the field-assisted mode and generates an asymmetric driving force in the field-free mode. In particular, the latter is guaranteed by the emerging Dzyaloshinskii-Moriya torque in altermagnets. Reconstructing crystal symmetry adds a new twist to the manipulation of altermagnetic order. It not only underpins the magnetic-memory and nano-oscillator technology^4,5 but also inspires crossover studies between altermagnetism and other research topics.

Nature (2025)

Electronic properties and materials, Magnetic properties and materials, Spintronics

Shielding Pt/γ-Mo2N by inert nano-overlays enables stable H2 production

Original Paper | Catalysis | 2025-02-11 19:00 EST

Zirui Gao, Aowen Li, Xingwu Liu, Mi Peng, Shixiang Yu, Maolin Wang, Yuzhen Ge, Chengyu Li, Tie Wang, Zhaohua Wang, Wu Zhou, Ding Ma

The use of reactive supports to disperse metal species is crucial for constructing highly efficient interfacial catalysts, by tuning the competitive reactant adsorption-activation pattern in supported metal catalysts into a non-competitive mechanism^1,2,3. However, these reactive supports are prone to deterioration during catalysis, limiting the lifespan of the catalyst and their potential practical applications⁴. New strategies are needed to simultaneously protect reactive supports and surface metal species without compromising the inherent catalytic performance. Here we report a new strategy to augment the structural stability of highly active interfacial catalysts by using inert nano-overlays to partially shield and partition the surface of the reactive support. Specifically, we demonstrate that atomically dispersed inert oxide nano-overlays on a highly active Pt/γ-Mo₂N catalyst can block the redundant surface sites of γ-Mo₂N responsible for surface oxidation of this reactive support and the resulting deactivation. This strategy yields an efficient and highly durable catalyst for hydrogen production by methanol-reforming reaction with a mere 0.26 wt% Pt loading, exhibiting a record-high turnover number, to our knowledge, of 15,300,000 and a notable apparent turnover frequency of \(\mathrm{24,500}\,{\text{mol}}_{ { {\rm{H}}}_{2}}\,{\text{mol}}_{ {\rm{metal}}}^{-1}\,{\text{h}}^{-1}\). This innovative approach showcases the prospects of reducing noble metal consumption and boosting longevity, which could be applied to design effective and stable heterogeneous catalysts.

Nature (2025)

Catalysis, Heterogeneous catalysis

Intrinsic electrical activity drives small-cell lung cancer progression

Original Paper | Cancer metabolism | 2025-02-11 19:00 EST

Paola Peinado, Marco Stazi, Claudio Ballabio, Michael-Bogdan Margineanu, Zhaoqi Li, Caterina I. Colón, Min-Shu Hsieh, Shreoshi Pal Choudhuri, Victor Stastny, Seth Hamilton, Alix Le Marois, Jodie Collingridge, Linus Conrad, Yinxing Chen, Sheng Rong Ng, Margaret Magendantz, Arjun Bhutkar, Jin-Shing Chen, Erik Sahai, Benjamin J. Drapkin, Tyler Jacks, Matthew G. Vander Heiden, Maksym V. Kopanitsa, Hugh P. C. Robinson, Leanne Li

Elevated or ectopic expression of neuronal receptors promotes tumour progression in many cancer types^1,2; neuroendocrine (NE) transformation of adenocarcinomas has also been associated with increased aggressiveness³. Whether the defining neuronal feature, namely electrical excitability, exists in cancer cells and impacts cancer progression remains mostly unexplored. Small-cell lung cancer (SCLC) is an archetypal example of a highly aggressive NE cancer and comprises two major distinct subpopulations: NE cells and non-NE cells^4,5. Here we show that NE cells, but not non-NE cells, are excitable, and their action potential firing directly promotes SCLC malignancy. However, the resultant high ATP demand leads to an unusual dependency on oxidative phosphorylation in NE cells. This finding contrasts with the properties of most cancer cells reported in the literature, which are non-excitable and rely heavily on aerobic glycolysis. Additionally, we found that non-NE cells metabolically support NE cells, a process akin to the astrocyte-neuron metabolite shuttle⁶. Finally, we observed drastic changes in the innervation landscape during SCLC progression, which coincided with increased intratumoural heterogeneity and elevated neuronal features in SCLC cells, suggesting an induction of a tumour-autonomous vicious cycle, driven by cancer cell-intrinsic electrical activity, which confers long-term tumorigenic capability and metastatic potential.

Nature (2025)

Cancer metabolism, Cancer models, Small-cell lung cancer, Tumour heterogeneity

Hydrogen escaping from a pair of exoplanets smaller than Neptune

Original Paper | Atmospheric dynamics | 2025-02-11 19:00 EST

R. O. Parke Loyd, Ethan Schreyer, James E. Owen, James G. Rogers, Madelyn I. Broome, Evgenya L. Shkolnik, Ruth Murray-Clay, David J. Wilson, Sarah Peacock, Johanna Teske, Hilke E. Schlichting, Girish M. Duvvuri, Allison Youngblood, P. Christian Schneider, Kevin France, Steven Giacalone, Natasha E. Batalha, Adam C. Schneider, Isabella Longo, Travis Barman, David R. Ardila

Exoplanet surveys have shown a class of abundant exoplanets smaller than Neptune on close, <100-day orbits^{1,<a data-test="citation-ref" data-track="click" data-track-action="reference anchor" data-track-label="link" href="https://www.nature.com/articles/s41586-024-08490-x#ref-CR2" id="ref-link-section-d7538224e956_1" title="Dong, S. & Zhu, Z. Fast rise of "Neptune-size" planets (4-8 R⊕) from P ∼ 10 to ∼250 days--statistics of Kepler planet candidates up to ∼0.75 AU. Astrophys. J. 778, 53 (2013).">2,3,4}. These planets form two populations separated by a natural division at about 1.8 R_⊕ termed the radius valley. It is uncertain whether these populations arose from separate dry versus water-rich formation channels, evolved apart because of long-term atmospheric loss or a combination of both^{5,6,7,8,9,10,11,12,13,14}. Here we report observations of ongoing hydrogen loss from two sibling planets, TOI-776 b (1.85 ± 0.13 R_⊕) and TOI-776 c (2.02 ± 0.14 R_⊕), the sizes of which near the radius valley and mature (1-4 Gyr) age make them valuable for investigating the origins of the divided population of which they are a part. During the transits of these planets, absorption appeared against the Lyman-α emission of the host star, compatible with hydrogen escape at rates equivalent to 0.03-0.6% and 0.1-0.9% of the total mass per billion years of each planet, respectively. Observations of the outer planet, TOI-776 c, are incompatible with an outflow of dissociated steam, suggesting both it and its inner sibling formed in a dry environment. These observations support the strong role of hydrogen loss in the evolution of close-orbiting sub-Neptunes^{5,6,7,8,15,16}.

Nature (2025)

Atmospheric dynamics, Exoplanets

Aqueous-based recycling of perovskite photovoltaics

Original Paper | Energy | 2025-02-11 19:00 EST

Xun Xiao, Niansheng Xu, Xueyu Tian, Tiankai Zhang, Bingzheng Wang, Xiaoming Wang, Yeming Xian, Chunyuan Lu, Xiangyu Ou, Yanfa Yan, Licheng Sun, Fengqi You, Feng Gao

Cumulative silicon photovoltaic (PV) waste highlights the importance of considering waste recycling before the commercialization of emerging PV technologies^1,2. Perovskite PVs are a promising next-generation technology³, in which recycling their end-of-life waste can reduce the toxic waste and retain resources^4,5. Here we report a low-cost, green-solvent-based holistic recycling strategy to restore all valuable components from perovskite PV waste. We develop an efficient aqueous-based perovskite recycling approach that can also rejuvenate degraded perovskites. We further extend the scope of recycling to charge-transport layers, substrates, cover glasses and metal electrodes. After repeated degradation-recycling processes, the recycled devices show similar efficiency and stability compared with the fresh devices. Our holistic recycling strategy reduces by 96.6% resource depletion and by 68.8% human toxicity (cancer effects) impacts associated with perovskite PVs compared with the landfill treatment. With recycling, the levelized cost of electricity also decreases for both utility-scale and residential systems. This study highlights unique opportunities of perovskite PVs for holistic recycling and paves the way for a sustainable perovskite solar economy.

Nature (2025)

Energy, Materials for energy and catalysis, Renewable energy, Solar cells

Learned magnetic map cues and two mechanisms of magnetoreception in turtles

Original Paper | Animal behaviour | 2025-02-11 19:00 EST

Kayla M. Goforth, Catherine M. F. Lohmann, Andrew Gavin, Reyco Henning, Andrew Harvey, Tara L. Hinton, Dana S. Lim, Kenneth J. Lohmann

Growing evidence indicates that migratory animals exploit the magnetic field of the Earth for navigation, both as a compass to determine direction and as a map to determine geographical position¹. It has long been proposed that, to navigate using a magnetic map, animals must learn the magnetic coordinates of the destination^2,3, yet the pivotal hypothesis that animals can learn magnetic signatures of geographical areas has, to our knowledge, yet to be tested. Here we report that an iconic navigating species, the loggerhead turtle (Caretta caretta), can learn such information. When fed repeatedly in magnetic fields replicating those that exist in particular oceanic locations, juvenile turtles learned to distinguish magnetic fields in which they encountered food from magnetic fields that exist elsewhere, an ability that might underlie foraging site fidelity. Conditioned responses in this new magnetic map assay were unaffected by radiofrequency oscillating magnetic fields, a treatment expected to disrupt radical-pair-based chemical magnetoreception^4,5,6, suggesting that the magnetic map sense of the turtle does not rely on this mechanism. By contrast, orientation behaviour that required use of the magnetic compass was disrupted by radiofrequency oscillating magnetic fields. The findings provide evidence that two different mechanisms of magnetoreception underlie the magnetic map and magnetic compass in sea turtles.

Nature (2025)

Animal behaviour, Animal migration

MorPhiC Consortium: towards functional characterization of all human genes

Review Paper | Cell signalling | 2025-02-11 19:00 EST

Mazhar Adli, Laralynne Przybyla, Tony Burdett, Paul W. Burridge, Pilar Cacheiro, Howard Y. Chang, Jesse M. Engreitz, Luke A. Gilbert, William J. Greenleaf, Li Hsu, Danwei Huangfu, Ling-Hong Hung, Anshul Kundaje, Sheng Li, Helen Parkinson, Xiaojie Qiu, Paul Robson, Stephan C. Schürer, Ali Shojaie, William C. Skarnes, Damian Smedley, Lorenz Studer, Wei Sun, Dušica Vidović, Thomas Vierbuchen, Brian S. White, Ka Yee Yeung, Feng Yue, Ting Zhou, Neda Abbaszadeh, Juliana Alcoforado Diniz, Anahita Amiri, Rohan N. V. S. R. K. Avireddy, Tao Bai, Dylan S. Baker, Jacob J. Baroch, Chia Chan, Sijie Chen, Xintong Chen, Hyein S. Cho, Anshul Choudhary, Caty E. Chung, Thomas J. Dahlstrom, Anthony Doty, Basak Eraslan, Adam L. Felsenfeld, Patrick J. Fleming, Colin F. Fletcher, Jesse Flores, William F. Flynn, Yihao Fu, Bryce Nobutoshi Fukuda, Jessica L. Garofalo, Rachel A. Glenn, Juhee Goyal, Alexandra M. Griffiths, Tingfeng Guo, Revant Gupta, Dipayan Gupta, Nan Hu, Yung-Hsin Huang, Aaron J. Huebner, Carolyn Hutter, Angelina Kendra, Gina Kirsammer, Orges A. Koci, Katerina Kraft, Zhaoheng Li, Shuzhao Li, Si Liu, Zukai Liu, Dingyu Liu, Nianping Liu, Renhe Luo, Davi Lyra Leite, Yuzhen Mao, Gabriel Marengo, Justin A. McDonough, Adrian Melo-Carrillo, Chen Meng, Eyal Metzl-Raz, Joshua M. Mitchell, Varun Mittal, Niharika Nasam, Ozlem Neyisci, Gang Ning, Devon Parker, Marcin Pilarczyk, Ajay Pillai, Olivier B. Poirion, Praeploy Pongpamorn, Arushi Rana, Jamilex Rivera-Diaz, Nicolette C. Ross, Enrique Sapena Ventura, Fidan Seker, Kaustav Sengupta, Anu Shivalikanjli, Wenzhuo Tang, Denis Torre, Ping Wang, Xianming Wang, De Xing, Dapeng Yang, Galabina N. Yordanova, Bo Yu, Tony Zeng, Stephen Zhang, Zhehao Zhang, Nan Zhang, Hengqiang Zhao, Shujian Zheng, Aaron Zhong, Justina Žurauskienė

Recent advances in functional genomics and human cellular models have substantially enhanced our understanding of the structure and regulation of the human genome. However, our grasp of the molecular functions of human genes remains incomplete and biased towards specific gene classes. The Molecular Phenotypes of Null Alleles in Cells (MorPhiC) Consortium aims to address this gap by creating a comprehensive catalogue of the molecular and cellular phenotypes associated with null alleles of all human genes using in vitro multicellular systems. In this Perspective, we present the strategic vision of the MorPhiC Consortium and discuss various strategies for generating null alleles, as well as the challenges involved. We describe the cellular models and scalable phenotypic readouts that will be used in the consortium's initial phase, focusing on 1,000 protein-coding genes. The resulting molecular and cellular data will be compiled into a catalogue of null-allele phenotypes. The methodologies developed in this phase will establish best practices for extending these approaches to all human protein-coding genes. The resources generated--including engineered cell lines, plasmids, phenotypic data, genomic information and computational tools--will be made available to the broader research community to facilitate deeper insights into human gene functions.

Nature 638, 351-359 (2025)

Cell signalling, Functional genomics, Genetic engineering, High-throughput screening, Induced pluripotent stem cells

The neuroimmune connectome in health and disease

Review Paper | Neuroimmunology | 2025-02-11 19:00 EST

Michael A. Wheeler, Francisco J. Quintana

The nervous and immune systems have complementary roles in the adaptation of organisms to environmental changes. However, the mechanisms that mediate cross-talk between the nervous and immune systems, called neuroimmune interactions, are poorly understood. In this Review, we summarize advances in the understanding of neuroimmune communication, with a principal focus on the central nervous system (CNS): its response to immune signals and the immunological consequences of CNS activity. We highlight these themes primarily as they relate to neurological diseases, the control of immunity, and the regulation of complex behaviours. We also consider the importance and challenges linked to the study of the neuroimmune connectome, which is defined as the totality of neuroimmune interactions in the body, because this provides a conceptual framework to identify mechanisms of disease pathogenesis and therapeutic approaches. Finally, we discuss how the latest techniques can advance our understanding of the neuroimmune connectome, and highlight the outstanding questions in the field.

Nature 638, 333-342 (2025)

Neuroimmunology

Direct experimental constraints on the spatial extent of a neutrino wavepacket

Original Paper | Experimental nuclear physics | 2025-02-11 19:00 EST

Joseph Smolsky, Kyle G. Leach, Ryan Abells, Pedro Amaro, Adrien Andoche, Keith Borbridge, Connor Bray, Robin Cantor, David Diercks, Spencer Fretwell, Stephan Friedrich, Abigail Gillespie, Mauro Guerra, Ad Hall, Cameron N. Harris, Jackson T. Harris, Leendert M. Hayen, Paul-Antoine Hervieux, Calvin Hinkle, Geon-Bo Kim, Inwook Kim, Amii Lamm, Annika Lennarz, Vincenzo Lordi, Jorge Machado, Andrew Marino, David McKeen, Xavier Mougeot, Francisco Ponce, Chris Ruiz, Amit Samanta, José Paulo Santos, Caitlyn Stone-Whitehead, John Taylor, Joseph Templet, Sriteja Upadhyayula, Louis Wagner, William K. Warburton

Despite their high relative abundance in our Universe, neutrinos are the least understood fundamental particles of nature. In fact, the quantum properties of neutrinos emitted in experimentally relevant sources are theoretically contested^1,2,3,4 and the spatial extent of the neutrino wavepacket is only loosely constrained by reactor neutrino oscillation data with a spread of 13 orders of magnitude^5,6. Here we present a method to directly access this quantity by precisely measuring the energy width of the recoil daughter nucleus emitted in the radioactive decay of beryllium-7. The final state in the decay process contains a recoiling lithium-7 nucleus, which is entangled with an electron neutrino at creation. The lithium-7 energy spectrum is measured to high precision by directly embedding beryllium-7 radioisotopes into a high-resolution superconducting tunnel junction that is operated as a cryogenic sensor. Under this approach, we set a lower limit on the Heisenberg spatial uncertainty of the recoil daughter of 6.2 pm, which implies that the final-state system is localized at a scale more than a thousand times larger than the nucleus itself. From this measurement, the first, to our knowledge, direct lower limit on the spatial extent of a neutrino wavepacket is extracted. These results may have implications in several areas including the theoretical understanding of neutrino properties, the nature of localization in weak nuclear decays and the interpretation of neutrino physics data.

Nature (2025)

Experimental nuclear physics, Experimental particle physics, Matter waves and particle beams

Earliest short-tailed bird from the Late Jurassic of China

Original Paper | Palaeontology | 2025-02-11 19:00 EST

Runsheng Chen, Min Wang, Liping Dong, Guowu Zhou, Xing Xu, Ke Deng, Liming Xu, Chi Zhang, Linchang Wang, Honggang Du, Ganmin Lin, Min Lin, Zhonghe Zhou

Recent macroevolutionary studies predict a diversification of early birds during the Jurassic period^1,2,3,4, but the unquestionable Jurassic bird fossil record is limited to Archaeopteryx^1,5,6, which has also been referred to deinonychosaurian dinosaurs by some analyses^7,8. Although they have feathered wings, the known Jurassic birds are more similar to non-avialan theropods in having the ancestral long reptilian tail^9,10,11. This is in stark contrast to most Cretaceous and crownward taxa, which have a short tail that terminates in a compound bone called the pygostyle^12,13,14. Here we report on the oldest short-tailed avialan, Baminornis zhenghensis gen. et sp. nov., from the recently discovered Late Jurassic Zhenghe Fauna¹⁵, which fills a noticeable spatio-temporal gap in the earliest branching avialan fossil record. B. zhenghensis exhibits a unique combination of derived ornithothoracine-like pectoral and pelvic girdles and plesiomorphic non-avialan maniraptoran hand, demonstrating mosaic evolution along stem avialan line. An avialan furcula collected from the same locality is referrable to ornithuromorphs on the basis of our morphometric and phylogenetic analyses. These newly discovered fossils demonstrate the early appearance of highly derived bird features, and together with an anchiornithine fossil from the same locality, they suggest an earlier origin of birds and a radiation of early birds in the Jurassic.

Nature 638, 441-448 (2025)

Palaeontology, Taxonomy

Stronger and coarser-grained biodegradable zinc alloys

Original Paper | Implants | 2025-02-11 19:00 EST

Chengcheng Wu, Fengxiang Lin, Hong Liu, Matthew H. Pelletier, Max Lloyd, Williams R. Walsh, Jian-Feng Nie

Zinc is emerging as a key material for next-generation biodegradable implants^1,2,3,4,5. However, its inherent softness limits its use in load-bearing orthopaedic implants. Although reducing the grain size of zinc can make it stronger, it also destabilizes its mechanical properties and thus makes it less durable at body temperature⁶. Here we show that extruded Zn alloys of dilute compositions can achieve ultrahigh strength and excellent durability when their micron-scale grain size is increased while maintaining a basal texture. In this inverse Hall-Petch effect, the dominant deformation mode changes from inter-granular grain boundary sliding and dynamic recrystallization at the original grain size to intra-granular pyramidal slip and unusual twinning at the increased grain size. The role of the anomalous twins, termed ‘accommodation twins' in this work, is to accommodate the altered grain shape in the plane lying perpendicular to the external loading direction, in contrast to the well-known ‘mechanical twins' whose role is to deliver plasticity along the external loading direction^{<a aria-label="Reference 7" data-test="citation-ref" data-track="click" data-track-action="reference anchor" data-track-label="link" href="https://www.nature.com/articles/s41586-024-08415-8#ref-CR7" id="ref-link-section-d11759135e403" title="Barnett, M. R. Twinning and the ductility of magnesium alloys: Part I: "Tension" twins. Mater. Sci. Eng. A 464, 1-7 (2007).">7,8}. The strength level achieved in these dilute zinc alloys is nearly double those of biodegradable implants made of magnesium alloys--making them the strongest and most stable biodegradable alloys available, to our knowledge, for fabricating bone fixation implants.

Nature (2025)

Implants, Metals and alloys

Converging mechanism of UM171 and KBTBD4 neomorphic cancer mutations

Original Paper | Cryoelectron microscopy | 2025-02-11 19:00 EST

Xiaowen Xie, Olivia Zhang, Megan J. R. Yeo, Ceejay Lee, Ran Tao, Stefan A. Harry, N. Connor Payne, Eunju Nam, Leena Paul, Yiran Li, Hui Si Kwok, Hanjie Jiang, Haibin Mao, Jennifer L. Hadley, Hong Lin, Melissa Batts, Pallavi M. Gosavi, Vincenzo D'Angiolella, Philip A. Cole, Ralph Mazitschek, Paul A. Northcott, Ning Zheng, Brian B. Liau

Cancer mutations can create neomorphic protein-protein interactions to drive aberrant function^1,2. As a substrate receptor of the CULLIN3-RING E3 ubiquitin ligase complex, KBTBD4 is recurrently mutated in medulloblastoma³, the most common embryonal brain tumour in children⁴. These mutations impart gain-of-function to KBTBD4 to induce aberrant degradation of the transcriptional corepressor CoREST⁵. However, their mechanism remains unresolved. Here we establish that KBTBD4 mutations promote CoREST degradation through engaging HDAC1/2 as the direct target of the mutant substrate receptor. Using deep mutational scanning, we chart the mutational landscape of the KBTBD4 cancer hotspot, revealing distinct preferences by which insertions and substitutions can promote gain-of-function and the critical residues involved in the hotspot interaction. Cryo-electron microscopy analysis of two distinct KBTBD4 cancer mutants bound to LSD1-HDAC1-CoREST reveals that a KBTBD4 homodimer asymmetrically engages HDAC1 with two KELCH-repeat β-propeller domains. The interface between HDAC1 and one of the KBTBD4 β-propellers is stabilized by the medulloblastoma mutations, which insert a bulky side chain into the HDAC1 active site pocket. Our structural and mutational analyses inform how this hotspot E3-neosubstrate interface can be chemically modulated. First, we unveil a converging shape-complementarity-based mechanism between gain-of-function E3 mutations and a molecular glue degrader, UM171. Second, we demonstrate that HDAC1/2 inhibitors can block the mutant KBTBD4-HDAC1 interface and proliferation of KBTBD4-mutant medulloblastoma cells. Altogether, our work reveals the structural and mechanistic basis of cancer mutation-driven neomorphic protein-protein interactions.

Nature (2025)

Cryoelectron microscopy, Mutagenesis, Paediatric cancer, Small molecules

The bulk motion of gas in the core of the Centaurus galaxy cluster

Original Paper | Galaxies and clusters | 2025-02-11 19:00 EST

Marc Audard, Hisamitsu Awaki, Ralf Ballhausen, Aya Bamba, Ehud Behar, Rozenn Boissay-Malaquin, Laura Brenneman, Gregory V. Brown, Lia Corrales, Elisa Costantini, Renata Cumbee, Chris Done, Tadayasu Dotani, Ken Ebisawa, Megan E. Eckart, Dominique Eckert, Teruaki Enoto, Satoshi Eguchi, Yuichiro Ezoe, Adam Foster, Ryuichi Fujimoto, Yutaka Fujita, Yasushi Fukazawa, Kotaro Fukushima, Akihiro Furuzawa, Luigi Gallo, Javier A. García, Liyi Gu, Matteo Guainazzi, Kouichi Hagino, Kenji Hamaguchi, Isamu Hatsukade, Katsuhiro Hayashi, Takayuki Hayashi, Natalie Hell, Edmund Hodges-Kluck, Ann Hornschemeier, Yuto Ichinohe, Manabu Ishida, Kumi Ishikawa, Yoshitaka Ishisaki, Jelle Kaastra, Timothy Kallman, Erin Kara, Satoru Katsuda, Yoshiaki Kanemaru, Richard Kelley, Caroline Kilbourne, Shunji Kitamoto, Shogo Kobayashi, Takayoshi Kohmura, Aya Kubota, Maurice Leutenegger, Michael Loewenstein, Yoshitomo Maeda, Maxim Markevitch, Hironori Matsumoto, Kyoko Matsushita, Dan McCammon, Brian McNamara, François Mernier, Eric D. Miller, Jon M. Miller, Ikuyuki Mitsuishi, Misaki Mizumoto, Tsunefumi Mizuno, Koji Mori, Koji Mukai, Hiroshi Murakami, Richard Mushotzky, Hiroshi Nakajima, Kazuhiro Nakazawa, Jan-Uwe Ness, Kumiko Nobukawa, Masayoshi Nobukawa, Hirofumi Noda, Hirokazu Odaka, Shoji Ogawa, Anna Ogorzalek, Takashi Okajima, Naomi Ota, Stephane Paltani, Robert Petre, Paul Plucinsky, Frederick Scott Porter, Katja Pottschmidt, Kosuke Sato, Toshiki Sato, Makoto Sawada, Hiromi Seta, Megumi Shidatsu, Aurora Simionescu, Randall Smith, Hiromasa Suzuki, Andrew Szymkowiak, Hiromitsu Takahashi, Mai Takeo, Toru Tamagawa, Keisuke Tamura, Takaaki Tanaka, Atsushi Tanimoto, Makoto Tashiro, Yukikatsu Terada, Yuichi Terashima, María Díaz Trigo, Yohko Tsuboi, Masahiro Tsujimoto, Hiroshi Tsunemi, Takeshi G. Tsuru, Hiroyuki Uchida, Nagomi Uchida, Yuusuke Uchida, Hideki Uchiyama, Yoshihiro Ueda, Shinichiro Uno, Jacco Vink, Shin Watanabe, Brian J. Williams, Satoshi Yamada, Shinya Yamada, Hiroya Yamaguchi, Kazutaka Yamaoka, Noriko Y. Yamasaki, Makoto Yamauchi, Shigeo Yamauchi, Tahir Yaqoob, Tomokage Yoneyama, Tessei Yoshida, Mihoko Yukita, Irina Zhuravleva, Marie Kondo, Norbert Werner, Tomáš Plšek, Ming Sun, Kokoro Hosogi, Anwesh Majumder

Galaxy clusters contain vast amounts of hot ionized gas known as the intracluster medium (ICM). In relaxed cluster cores, the radiative cooling time of the ICM is shorter than the age of the cluster. However, the absence of line emission associated with cooling suggests heating mechanisms that offset the cooling, with feedback from active galactic nuclei (AGNs) being the most likely source^1,2. Turbulence and bulk motions, such as the oscillating (‘sloshing') motion of the core gas in the cluster potential well, have also been proposed as mechanisms for heat distribution from the outside of the core^3,4. Here we present X-ray spectroscopic observations of the Centaurus galaxy cluster with the X-Ray Imaging and Spectroscopy Mission satellite. We find that the hot gas flows along the line of sight relative to the central galaxy, with velocities from 130 km s^-1 to 310 km s^-1 within about 30 kpc of the centre. This indicates bulk flow consistent with core gas sloshing. Although the bulk flow may prevent excessive accumulation of cooled gas at the centre, it could distribute the heat injected by the AGN and bring in thermal energy from the surrounding ICM. The velocity dispersion of the gas is found to be only ≲120 km s^-1 in the core, even within about 10 kpc of the AGN. This suggests that the influence of the AGN on the surrounding ICM motion is limited in the cluster.

Nature 638, 365-369 (2025)

Galaxies and clusters, High-energy astrophysics

Balanced plant helper NLR activation by a modified host protein complex

Original Paper | Cryoelectron microscopy | 2025-02-11 19:00 EST

Shijia Huang, Junli Wang, Ridan Song, Aolin Jia, Yu Xiao, Yue Sun, Lin Wang, Dennis Mahr, Zhongshou Wu, Zhifu Han, Xin Li, Jane E. Parker, Jijie Chai

Nucleotide-binding leucine-rich repeat (NLR) receptors play crucial roles in plant immunity by sensing pathogen effectors¹. In Arabidopsis, certain sensor NLRs function as NADases to catalyse the production of second messengers^2,3, which can be recognized by enhanced disease susceptibility 1 (EDS1) with its partner senescence-associated gene 101 (SAG101), to activate helper NLR N requirement gene 1 (NRG1)⁴. A cryoelectron microscopy structure shows that second-messenger-activated EDS1-SAG101 mainly contacts the leucine-rich repeat domain of NRG1A to mediate the formation of an induced EDS1-SAG101-NRG1A complex. Structural comparisons show that binding of a second messenger induces conformational changes in EDS1-SAG101, which are recognized by NRG1A, leading to its allosteric activation. We further show that an inhibitory NRG1 family member, NRG1C, efficiently outcompetes NRG1A for binding to second-messenger-activated EDS1-SAG101. These findings uncover mechanisms for NRG1A activation through its recognition of a modified host EDS1-SAG101 complex, and NRG1A inhibition by NRG1C through sequestration of the activated EDS1-SAG101, thus shedding light on the activation and constraint of a central plant immune response system.

Nature (2025)

Cryoelectron microscopy, Plant immunity, Plant signalling, X-ray crystallography

A crucial role for the cortical amygdala in shaping social encounters

Original Paper | Social behaviour | 2025-02-11 19:00 EST

Antonio V. Aubry, Romain Durand-de Cuttoli, Elizabeth Karpman, Rachel L. Fisher-Foye, Lyonna F. Parise, Flurin Cathomas, C. Joseph Burnett, Yewon Yang, Chongzhen Yuan, Alexa R. LaBanca, Kenny L. Chan, Kion T. Winston, Hsiao-yun Lin, Farah Dackour, Arman A. Tavallaei, Johana Alvarez, Tadaaki Nishioka, Hirofumi Morishita, Robert C. Froemke, Long Li, Scott J. Russo

Aggression is an evolutionarily conserved behaviour that controls social hierarchies and protects valuable resources. In mice, aggressive behaviour can be broken down into an appetitive phase, which involves approach and investigation, and a consummatory phase, which involves biting, kicking and wrestling¹. Here, by performing an unsupervised weighted correlation network analysis on whole-brain FOS expression in mice, we identify a cluster of brain regions, including hypothalamic and amygdalar subregions and olfactory cortical regions, that are highly co-activated in male but not in female aggressors. The posterolateral cortical amygdala (COApl)--an extended olfactory structure--was found to be a hub region, on the basis of the number and strength of correlations with other regions in the cluster. Our data also show that oestrogen receptor 1 (Esr1)-expressing cells in the COApl (COApl^Esr1) exhibit increased activity during attack behaviour and during bouts of investigation that precede an attack, in male mice only. Chemogenetic or optogenetic inhibition of COApl^Esr1 cells in male aggressors reduces aggression and increases pro-social investigation without affecting social reward and reinforcement behaviour. We further show that COApl^Esr1 projections to the ventromedial hypothalamus and central amygdala are necessary for these behaviours. Collectively, these data suggest that, in aggressive males, COApl^Esr1 cells respond specifically to social stimuli, thereby enhancing their salience and promoting attack behaviour.

Nature (2025)

Social behaviour, Social neuroscience

Activation and inhibition mechanisms of a plant helper NLR

Original Paper | Plant immunity | 2025-02-11 19:00 EST

Yinyan Xiao, Xiaoxian Wu, Zaiqing Wang, Kexin Ji, Yang Zhao, Yu Zhang, Li Wan

Plant nucleotide-binding leucine-rich repeat (NLR) receptors sense pathogen effectors and form resistosomes to confer immunity¹. Some sensor NLR resistosomes produce small molecules to induce formation of a heterotrimer complex with two lipase-like proteins, EDS1 and SAG101, and a helper NLR called NRG1 (refs. ^2,3). Activation of sensor NLR resistosomes also triggers NRG1 oligomerization and resistosome formation at the plasma membrane^4,5. We demonstrate that the Arabidopsis AtEDS1-AtSAG101-AtNRG1A heterotrimer formation is stabilized by the AtNRG1A loss-of-oligomerization mutant L134E^{5,<a aria-label="Reference 6" data-test="citation-ref" data-track="click" data-track-action="reference anchor" data-track-label="link" href="https://www.nature.com/articles/s41586-024-08517-3#ref-CR6" id="ref-link-section-d12122983e403" title="Jacob, P. et al. Plant "helper" immune receptors are Ca2+-permeable nonselective cation channels. Science 373, 420-425 (2021).">6}. We report structures of AtEDS1-AtSAG101-AtNRG1A L134E and AtEDS1-AtSAG101-AtNRG1C heterotrimers with similar assembly mechanisms. AtNRG1A signalling is activated by the interaction with the AtEDS1-AtSAG101 heterodimer in complex with their small-molecule ligand. The truncated AtNRG1C maintains core interacting domains of AtNRG1A but develops further interactions with AtEDS1-AtSAG101 to outcompete AtNRG1A. Moreover, AtNRG1C lacks an N-terminal signalling domain and shows nucleocytoplasmic localization, facilitating its sequestration of AtEDS1-AtSAG101, which is also nucleocytoplasmic. Our study shows the activation and inhibition mechanisms of a plant helper NLR.

Nature (2025)

Plant immunity, Structural biology

Measuring racial educational disparities over time amongst top achievers

Original Paper | Economics | 2025-02-11 19:00 EST

Uditi Karna, Min Sok Lee, John A. List, Andrew Simon, Haruka Uchida

Educational disparities remain a key contributor to increasing social and wealth inequalities. To address this, researchers and policymakers have focused on average differences between racial groups or differences among students who are falling behind¹. This focus potentially leads to educational triage, diverting resources away from high-achieving students, including those from racial minorities^2,3. Here we focus on the ‘racial excellence gap'--the difference in the likelihood that students from racial minorities (Black and Hispanic) reach the highest levels of academic achievement compared with their non-minority (white and Asian) peers. There is a shortage of evidence that systematically measures the magnitude of the excellence gap and how it evolves^4,5. Using longitudinal, statewide, administrative data, we document eight facts regarding the excellence gap from third grade (typically ages 8-9) to high school (typically ages 14-18), link the stability of excellence gaps and student backgrounds, and assess the efficacy of public policies. We show that excellence gaps in maths and reading are evident by the third grade and grow slightly over time, especially for female students. About one third of the gap is explained by a student's socioeconomic status, and about one tenth is explained by the school environment. Top-achieving racial minority students are also less likely to persist in excellence as they progress through school. Moreover, state accountability policies that direct additional resources to reduce non-race-based inequality⁶ had minimal effects on the racial excellence gaps. Documenting these patterns is an important step towards eliminating excellence gaps and removing the ‘racial glass ceiling'.

Nature (2025)

Economics, Education

External Li supply reshapes Li deficiency and lifetime limit of batteries

Original Paper | Batteries | 2025-02-11 19:00 EST

Shu Chen, Guanbin Wu, Haibo Jiang, Jifeng Wang, Tiantian Chen, Chenyang Han, Wenwen Wang, Rongchen Yang, Jiahua Zhao, Zhihang Tang, Xiaocheng Gong, Chuanfa Li, Mengyao Zhu, Kun Zhang, Yifei Xu, Ying Wang, Zhe Hu, Peining Chen, Bingjie Wang, Kai Zhang, Yongyao Xia, Huisheng Peng, Yue Gao

Lithium (Li) ions are central to the energy storing functionality of rechargeable batteries¹. Present technology relies on sophisticated Li-inclusive electrode materials to provide Li ions and exactingly protect them to ensure a decent lifetime². Li-deficient materials are thus excluded from battery design, and the battery fails when active Li ions are consumed³. Our study breaks this limit by means of a cell-level Li supply strategy. This involves externally adding an organic Li salt into an assembled cell, which decomposes during cell formation, liberating Li ions and expelling organic ligands as gases. This non-invasive and rapid process preserves cell integrity without necessitating disassembly. We leveraged machine learning to discover such functional salts and identified lithium trifluoromethanesulfinate (LiSO₂CF₃) with optimal electrochemical activity, potential, product formation, electrolyte solubility and specific capacity. As a proof-of-concept, we demonstrated a 3.0 V, 1,192 Wh kg^-1 Li-free cathode, chromium oxide, in the anode-less cell, as well as an organic sulfurized polyacrylonitrile cathode incorporated in a 388 Wh kg^-1 pouch cell with a 440-cycle life. These systems exhibit improved energy density, enhanced sustainability and reduced cost compared with conventional Li-ion batteries. Furthermore, the lifetime of commercial LiFePO₄ batteries was extended by at least an order of magnitude. With repeated external Li supplies, a commercial graphite|LiFePO₄ cell displayed a capacity retention of 96.0% after 11,818 cycles.

Nature (2025)

Batteries

Global biodiversity loss from outsourced deforestation

Original Paper | Biodiversity | 2025-02-11 19:00 EST

R. Alex Wiebe, David S. Wilcove

Globalization increasingly allows countries to externalize the environmental costs of land use, including biodiversity loss¹. So far, we have a very incomplete understanding of how countries cause biodiversity loss outside their own borders through their demand for agricultural and forestry products grown in other countries². Here we quantify the global range losses to forest vertebrates from 2001 to 2015 caused by deforestation attributable to 24 developed countries by means of their consumption of products obtained through global supply chains. We show that these driver countries are responsible for much greater cumulative range loss to species outside their own borders than within them. These international impacts were concentrated geographically, allowing us to map global hotspots of outsourced losses of biodiversity. Countries had the greatest external impacts on species occurring in nearby regions. However, in a few cases, developed countries also inflicted disproportionate harm on vertebrates in distant countries.

Nature (2025)

Biodiversity, Conservation biology, Environmental impact, Macroecology

Nature Materials

Activating deformation twinning in cubic boron nitride

Original Paper | Ceramics | 2025-02-11 19:00 EST

Yeqiang Bu, Zhengping Su, Junquan Huang, Ke Tong, Penghui Li, Chong Wang, Tianye Jin, Song Zhao, Zhisheng Zhao, Alexander Soldatov, Yanbin Wang, Bo Xu, Zhongyuan Liu, Anmin Nie, Hongtao Wang, Wei Yang, Yongjun Tian

Deformation twinning, a phenomenon primarily documented within metallic systems, has remained essentially unexplored in covalent materials due to the formidable challenges posed by their inherent extreme hardness and brittleness. Here, by employing a five-degree-of-freedom nano-manipulation stage inside a transmission electron microscope, we reveal a loading-specific twinning criterion for cubic boron nitride and successfully activate extensive deformation twinning with substantial improvements in mechanical properties in <100>-oriented cubic boron nitride submicrometre pillars at room temperature. Beyond cubic boron nitride, this criterion is also proven widely applicable across a spectrum of covalent materials. Investigations on the twinning dynamics at the atomic level in cubic boron nitride suggest a continuous-transition-mediated pathway. These findings substantially advance our comprehension of twinning mechanisms in covalent face-centred cubic materials, and herald a promising avenue for microstructural engineering aimed at enhancing the strength and toughness of these materials in their applications.

Nat. Mater. (2025)

Ceramics, Mechanical properties

Anomalous thermal transport in Eshelby twisted van der Waals nanowires

Original Paper | Nanowires | 2025-02-11 19:00 EST

Yin Liu, Lei Jin, Tribhuwan Pandey, Haoye Sun, Yuzi Liu, Xun Li, Alejandro Rodriguez, Yueyin Wang, Tao Zhou, Rui Chen, Yongwen Sun, Yang Yang, Daryl C. Chrzan, Lucas Lindsay, Junqiao Wu, Jie Yao

Dislocations in van der Waals (vdW) layered nanomaterials induce strain and structural changes that substantially impact thermal transport. Understanding these effects could enable the manipulation of dislocations for improved thermoelectric and optoelectronic applications, but experimental insights remain limited. In this study, we use synthetic Eshelby twisted vdW GeS nanowires (NWs) with single screw dislocations as a model system to explore the interplay between dislocation-induced structural modifications and lattice thermal conductivity. Our measurements reveal a monoclinic structure stabilized by the dislocation, leading to a substantial drop in thermal conductivity for larger-diameter NWs (70% at room temperature), supported by first-principles calculations. Interestingly, we also find an anomalous enhancement of thermal conductivity with decreasing diameter in twisted NWs, contrary to typical trends in non-twisted GeS NWs. This is attributed to increased conductivity near the NW cores due to compressive strain around the central dislocations, and aligns with a density-functional-theory-informed core-shell model. Our results highlight the critical role of dislocations in thermal conduction, providing fundamental insights for defect and strain engineering in advanced thermal applications.

Nat. Mater. (2025)

Nanowires, Two-dimensional materials

Physical Review Letters

Distinguishable Consequence of Classical Gravity on Quantum Matter

Research article | Alternative gravity theories | 2025-02-12 05:00 EST

Serhii Kryhin and Vivishek Sudhir

What if gravity is classical? If true, a consistent coexistence of classical gravity and quantum matter requires that gravity exhibit irreducible fluctuations. These fluctuations can mediate classical correlations, but not quantum entanglement, between the quantized motion of the gravitationally interacting matter. We use a consistent theory of quantum-classical dynamics in the Newtonian limit of gravity to show that experimentally relevant observables can conclusively test the hypothesis that gravity is classical. This can be done, for example, by letting highly coherent source masses interact with each other gravitationally, and performing precise measurements of the cross-correlation of their motion. Theory predicts a characteristic phase response that distinguishes classical gravity from quantum gravity, and from naive sources of decoherence. Such experiments are imminently viable.

Phys. Rev. Lett. 134, 061501 (2025)

Alternative gravity theories, Open quantum systems & decoherence, Optomechanics, Lindblad equation, Master equation, Path-integral methods

Atoms as Electron Accelerators for Measuring the Cross Section of \({e}^{+}{e}^{- }\rightarrow \text{Hadrons}\)

Research article | Lepton-lepton interactions | 2025-02-12 05:00 EST

Fernando Arias-Aragón, Luc Darmé, Giovanni Grilli di Cortona, and Enrico Nardi

The hadronic vacuum polarization contribution to \((g- 2{)}_{\mu }\) can be determined via dispersive methods from \({e}^{+}{e}^{- }\rightarrow \text{hadrons}\) data. We propose a novel approach to measure the hadronic cross section \({\sigma }_{\mathrm{had}}(s)\) as an alternative to the initial-state radiation and energy scan techniques, which relies on positron annihilation off atomic electrons of a high \(Z\) target (\(^{238}\mathrm{U}\), \(Z=92\)). We show that by leveraging the relativistic electron velocities of the inner atomic shells, a high-intensity 12 GeV positron beam, such as the one foreseen at JLab, can allow measuring \({\sigma }_{\mathrm{had}}(s)\) with high statistical accuracy from the two-pion threshold up to above \(\sqrt{s}\sim 1\text{ }\text{ }\mathrm{GeV}\).

Phys. Rev. Lett. 134, 061802 (2025)

Lepton-lepton interactions, Magnetic moment, Particle interactions, Phenomenology

Jet Definition and Transverse-Momentum--Dependent Factorization in Semi-Inclusive Deep-Inelastic Scattering

Research article | Phenomenology | 2025-02-12 05:00 EST

Paul Caucal, Edmond Iancu, A. H. Mueller, and Feng Yuan

Using the color dipole picture of deep inelastic scattering (DIS) and the color glass condensate effective theory, we study semi-inclusive jet production in DIS at small \(x\) in the limit where the photon virtuality \({Q}^{2}\) is much larger than the transverse momentum squared \({P}_{\perp }^{2}\) of the produced jet. In this limit, the cross section is dominated by aligned jet configurations, that is, quark--antiquark pairs in which one of the fermions---the would-be struck quark in the Breit frame---carries most of the longitudinal momentum of the virtual photon. We show that physically meaningful jet definitions in DIS are such that the effective axis of the jet sourced by the struck quark is controlled by its virtuality rather than by its transverse momentum. For such jet definitions, we show that the next-to-leading order cross section admits factorization in terms of the (sea) quark transverse momentum dependent distribution, which in turn satisfies a universal Dokshitzer-Gribov-Lipatov-Altarelli-Parisi and Sudakov evolution.

Phys. Rev. Lett. 134, 061903 (2025)

Phenomenology, Quantum chromodynamics, Quark & gluon jets, Strong interaction, Transverse momentum dependent distribution

Neutral Sulfur Atom Formation in Decay of Deep Core Holes in \({\mathrm{SF}}_{6}\)

Research article | Energy levels | 2025-02-12 05:00 EST

Oksana Travnikova, Florian Trinter, Marcus Agåker, Giorgio Visentin, Joakim Andersson, Ludvig Kjellsson, Iyas Ismail, Nicolas Velasquez, Dimitris Koulentianos, Manuel Harder, Zhong Yin, Johan Söderström, Tatiana Marchenko, Renaud Guillemin, O. Dennis McGinnis, Hans Ågren, Stephan Fritzsche, Marc Simon, Jan-Erik Rubensson, and Joseph Nordgren

Dissociation upon sulfur \(K\)-shell excitation or ionization of \({\mathrm{SF}}_{6}\) is studied by sulfur \(L\)-shell emission spectroscopy using synchrotron radiation and multiconfiguration Dirac-Hartree-Fock calculations of emission energies and transition rates. The decay path involves in particular Auger emission with the ejection of one or more electrons, leading to singly or multiply charged intermediate states. Nevertheless, the results of the study show that the observed photon emission at 151--152 eV following excitation at 2485--2489 eV originates dominantly from transitions in neutral sulfur. This clearly indicates that the central atom retains its electrons in a dissociation process where all fluorine atoms detach before the S \(2p\) decay.

Phys. Rev. Lett. 134, 063003 (2025)

Energy levels, Molecular dissociation, Molecular spectra, Single- and few-photon ionization & excitation, Molecules, Configuration interaction, Fluorescence, Hartree-Fock methods, Resonance fluorescence, Resonant inelastic x-ray scattering, X-ray emission spectroscopy

Floquet Engineering the Quantum Rabi Model in the Ultrastrong Coupling Regime

Research article | Atom optics | 2025-02-12 05:00 EST

Kamran Akbari, Franco Nori, and Stephen Hughes

We study the quantum Rabi model for a two-level system coupled to a quantized cavity mode under periodic modulation of the cavity-dipole coupling in the ultrastrong coupling regime, leading to rich Floquet states. Exploiting the quantum vacuum, we show how purely mechanical driving can produce real photons, depending on the strength and frequency of the periodic coupling rate. This scheme is promising for the coherent manipulation of hybrid quantum systems and quantum vacuum effects, with potential applications for quantum state engineering, quantum information processing, and the study of nonequilibrium quantum phenomena.

Phys. Rev. Lett. 134, 063602 (2025)

Atom optics, Cavity quantum electrodynamics, Atoms, Floquet systems, Bloch-Floquet theorem, Dipole approximation, Rabi model, Schroedinger equation, Strong-field approximation

Nonuniform Wave Momentum Band Gap in Biaxial Anisotropic Photonic Time Crystals

Research article | Metamaterials | 2025-02-12 05:00 EST

Junhua Dong, Sihao Zhang, Huan He, Huanan Li, and Jingjun Xu

Photonic time crystals (PTCs) host momentum band gaps, enabling intriguing nonresonant light amplification in propagating waves, but opening substantial band gaps demands refractive index changes too extreme for conventional nonlinear optics. Here, we introduce momentum band gaps for nonuniform waves, including evanescent and ghost types, by extending PTCs to biaxial anisotropic photonic time crystals that periodically alternate between uniform biaxial anisotropy and isotropic media over time. We show that ghost waves, unlike evanescent waves, sustain only momentum band gaps, opening wide band gaps at even the smallest modulation depths. Moreover, we demonstrate momentum band-gap effects on nonuniform waves that can be amplified or, through decaying modes, selectively attenuated. We find that ghost wave momentum band gaps uniquely boost refracted over reflected waves under one-way incidence, in stark contrast to the balanced amplification seen in both propagating and evanescent waves. Our approach expands time-varying metamaterials by integrating wave characteristics, bridging the gap between conventional nonlinear optics and PTC momentum band gaps, and shedding new light on extreme manipulation of surface polaritons.

Phys. Rev. Lett. 134, 063801 (2025)

Metamaterials, Nonlinear optics, Photonic crystals, Photonics, Time crystals

Thermal Properties of the Superconductor--Quantum Hall Interface

Research article | Quantum Hall effect | 2025-02-12 05:00 EST

Lingfei Zhao, Trevyn F. Q. Larson, Zubair Iftikhar, John Chiles, Kenji Watanabe, Takashi Taniguchi, François Amet, and Gleb Finkelstein

Investigation of current fluctuations in the thermal properties of superconductor-quantum Hall interfaces reveals a significant amount of excess noise when the interface is biased.

Phys. Rev. Lett. 134, 066001 (2025)

Quantum Hall effect, Topological superconductors, Vortices in superconductors, Graphene, Type-II superconductors

Striped Twisted State in the Orientational Epitaxy on Quasicrystals

Research article | Pattern formation | 2025-02-12 05:00 EST

Nicola Manini, Mario Forzanini, Sebastiano Pagano, Marco Bellagente, Martino Colombo, Dario Bertazioli, Tommaso Salvalaggio, Andrea Vanossi, Davide Vanossi, Emanuele Panizon, Erio Tosatti, and Giuseppe E. Santoro

The optimal ''twisted'' geometry of a crystalline layer on a crystal has long been known, but that on a quasicrystal is still unknown and open. We predict analytically that the layer equilibrium configuration will generally exhibit a nonzero misfit angle. The theory perfectly agrees with numerical optimization of a colloid monolayer on a quasiperiodic decagonal optical lattice. Strikingly different from crystal-on-crystal epitaxy, the structure of the novel emerging twisted state exhibits an unexpected stripe pattern. Its high anisotropy should reflect on the tribomechanical properties of this unconventional interface.

Phys. Rev. Lett. 134, 066202 (2025)

Pattern formation, Quasicrystalline structure, Charged colloids, Solid-solid interfaces, Linear response theory

Revisiting the Formulation of Charged Defect in Solids

Research article | Point defects | 2025-02-12 05:00 EST

Hanzhi Shang, Zeyu Jiang, Yiyang Sun, D. West, and Shengbai Zhang

A one-shot linear response-based method accurately estimates the defect formation energy of smaller supercells.

Phys. Rev. Lett. 134, 066401 (2025)

Point defects, Doped semiconductors, Density functional theory development, First-principles calculations

Large Spin-Orbit Torque in \(a\)-Plane \(\alpha \text{- }{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}/\mathrm{Pt}\) Bilayers

Research article | Antiferromagnetism | 2025-02-12 05:00 EST

Igor Lyalin, Hantao Zhang, Justin Michel, Daniel Russell, Fengyuan Yang, Ran Cheng, and Roland K. Kawakami

Realization of efficient spin-orbit torque switching of the N'eel vector in insulating antiferromagnets is a challenge, often complicated by spurious effects. Quantifying the spin-orbit torques in antiferromagnet or heavy metal heterostructures is an important first step toward this goal. Here, we employ magneto-optic techniques to study dampinglike spin-orbit torque (DL-SOT) in \(a\)-plane \(\alpha \text{- }{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}\) (hematite) with a Pt spin-orbit overlayer. We find that the DL-SOT efficiency is 2 orders of magnitude larger than reported in \(c\)- and \(r\)-plane hematite/Pt using harmonic Hall techniques. The large magnitude of DL-SOT is supported by direct imaging of current-induced motion of antiferromagnetic domains that happens at moderate current densities. Our study introduces a new method for quantifying spin-orbit torque in antiferromagnets with a small canted moment and identifies \(a\)-plane \(\alpha \text{- }{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}\) as a promising candidate to realize efficient SOT switching.

Phys. Rev. Lett. 134, 066701 (2025)

Antiferromagnetism, Magneto-optical Kerr effect, Spin-orbit torque, Spintronics, Heterostructures

Room-Temperature Amplified Spontaneous Emission in Two-Dimensional \({\mathrm{WS}}_{2}\) beyond Exciton Mott Transition

Research article | Excitons | 2025-02-12 05:00 EST

Yan Xu, Yihan Xiang, Meng Shi, Baoxing Zhai, Wei Dai, Ti Wang, Xiaoze Liu, Yiling Yu, and Jun He

Amplified spontaneous emission from a degenerate electron-hole plasma in a 2D semiconductor has been demonstrated for the first time.

Phys. Rev. Lett. 134, 066904 (2025)

Excitons, Light-matter interaction, Phase transitions, Spontaneous emission, 2-dimensional systems, Semiconductors, Cavity resonators, Photoexcitation, Photoluminescence

Exact Solution of Bipartite Fluctuations in One-Dimensional Fermions

Research article | Cold atoms & matter waves | 2025-02-12 05:00 EST

Kazuya Fujimoto and Tomohiro Sasamoto

Emergence of hydrodynamics in quantum many-body systems has recently garnered growing interest. The recent experiment of ultracold atoms [J. F. Wienand et al., Nat. Phys. 20, 1732 (2024)] studied emergent hydrodynamics in hard-core bosons using a bipartite fluctuation, which quantifies how the particle number fluctuates in a subsystem. In this Letter, we theoretically study the variance of a bipartite fluctuation in one-dimensional noninteracting fermionic dynamics starting from an alternating state, deriving the exact solution of the variance and its asymptotic linear growth law for the long-time dynamics. To compare the theoretical prediction with the experiment, we generalize our exact solution by incorporating the incompleteness of the initial alternating state, deriving the general linear growth law analytically. We find that it shows good agreement with the experimentally observed variance growth without any fitting parameters. Furthermore, we estimate a timescale for the local equilibration using our exact solution, finding that the timescale is independent of the initial incompleteness. To investigate the interaction effect, we implement numerical studies for the variance growth in interacting fermions, which has yet to be explored experimentally. As a result, we find that the presence of interactions breaks the linear variance growth derived in the noninteracting fermions. Our exact solutions and numerical findings here lay a foundation for growing bipartite fluctuations in quantum many-body dynamics.

Phys. Rev. Lett. 134, 067101 (2025)

Cold atoms & matter waves, Nonequilibrium statistical mechanics, Quantum quench, Nonequilibrium lattice models, Nonequilibrium systems, Quantum many-body systems

Physical Review X

Self-Consistent Current Response Theory of Unjamming and Vibrational Modes in Low-Temperature Amorphous Solids

Research article | Dynamical phase transitions | 2025-02-12 05:00 EST

Florian Vogel, Philipp Baumgärtel, and Matthias Fuchs

A self-consistent theory of the unjamming transition, applied to a model of amorphous solids described using Euclidean random matrices, elucidates universal vibrational properties.

Phys. Rev. X 15, 011030 (2025)

Dynamical phase transitions, Jamming, Mode coupling theory, Random matrix theory

Designs via Free Probability

Research article | Eigenstate thermalization | 2025-02-12 05:00 EST

Michele Fava, Jorge Kurchan, and Silvia Pappalardi

A tool that bridges the gap between k designs, which simulate quantum randomness, and quantum chaos and thermalization sheds new light on how quantum systems evolve into randomness.

Phys. Rev. X 15, 011031 (2025)

Eigenstate thermalization, Quantum channels, Quantum chaos, Quantum correlations in quantum information, Combinatorics, Probability theory, Random matrix theory

arXiv

Superconducting LaPtH\(_{ 6 }\) with triatomic hydrogen units

New Submission | Superconductivity (cond-mat.supr-con) | 2025-02-12 20:00 EST

T. Ishikawa, Y. Tanaka, S. Tsuneyuki

To veryfy "hot supreconductivity" recently proposed in lanthanum hydride-based compounds, we explored thermodynamically stable and superconducting phases in the lanthanum (La)-platinum (Pt)-hydrogen (H) ternary system at 20 GPa using an evolutionary construction scheme of a formation-enthalpy convex hull, universal neural network potential calculations, and density functional theory calculations. Although we found no evidence of the hot superconductivity in this ternary system, we predicted a unique compound, LaPtH\(_{ 6 }\), which has equilateral triangular H\(_{ 3 }\) units nearly forming a two-dimensional kagome lattice between La and Pt layers and shows the superconductivity at 18.67 K. This structure is dynamically stable from ambient pressure to at least 200 GPa and the superconducting critical temperature increases from 13.51 to 40.63 K.

arXiv:2502.06821 (2025)

Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)

6 pages, 5 figures. arXiv admin note: text overlap with arXiv:2312.01290

Distinguishing thermal fluctuations from polaron formation in halide perovskites

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Bai-Qing Zhao (1, 2), Xuan-Yan Chen (3), Chuan-Nan Li (2), Jinshan Li (1), Chris G. Van de Walle (2), Xie Zhang (1) ((1) School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, China (2) Materials Department, University of California, Santa Barbara, CA, USA (3) Sustainable Energy and Environment Thrust, Function Hub, Hong Kong University of Science and Technology (Guangzhou), Guangzhou, China)

Recent angle-resolved photoelectron spectroscopy (ARPES) measurements of the hole effective mass in CsPbBr\(_3\) revealed an enhancement of $\(50 % compared to the bare mass computed from first principles for CsPbBr\)_3$ at \(T = 0 K\). This large enhancement was interpreted as evidence of polaron formation. Employing accurate finite-temperature first-principles calculations, we show that the calculated hole effective mass of CsPbBr\(_3\) at \(T = 300 K\) can explain experimental results without invoking polarons. Thermal fluctuations are particularly strong in halide perovskites compared to conventional semiconductors such as Si and GaAs, and cannot be ignored when comparing with experiment. We not only resolve the debate on polaron formation in halide perovskites, but also demonstrate the general importance of including thermal fluctuations in first-principles calculations for strongly anharmonic materials.

arXiv:2502.06904 (2025)

Materials Science (cond-mat.mtrl-sci)

On the Entire Structure of the Energy Bands of 1D Moiré Superchain

New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-02-12 20:00 EST

Dmitrii Vorobev, Stom (Yiheng)Chen, Grigory M. Tarnopolsky

We consider a general model of two atomic chains forming a moiré pattern due to a small mismatch in their lattice spacings, given by \(\theta = (a_{1} - a_{2})/a_{2}\). Assuming arbitrary single-band dispersion relations \(\varepsilon_{1}(p)\) and \(\varepsilon_{2}(q)\) for the chains, along with an arbitrary inter-chain coupling term \(T(x)\), we show that the entire spectrum of such a one-dimensional moiré superchain is governed by a single three-term recurrence (TTR) relation. We analyze this TTR relation using the discrete WKB method and demonstrate how the entire structure of the spectrum as well as emergence of flat bands can be easily identified from a pair of upper and lower potential functions of the TTR relation. We also comment on the chiral limit of the moiré superchain, which can be viewed, in some sense, as a 1D analog of the chiral limit of Twisted Bilayer Graphene.

arXiv:2502.06938 (2025)

Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

7 pages, 4 figures

Effect of disorder and strain on the operation of planar Ge hole spin qubits

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Abhikbrata Sarkar, Pratik Chowdhury, Xuedong Hu, Andre Saraiva, A. S. Dzurak, A. R. Hamilton, Rajib Rahman, S. Das Sarma, Dimitrie Culcer

Germanium quantum dots in strained \(\text{Ge}/\text{Si}_{1-x}\text{Ge}_{x}\) heterostructures exhibit fast and coherent hole qubit control in experiments. In this work, we theoretically and numerically address the effects of random alloy disorder and gate-induced strain on the operation of planar Ge hole spin qubits. Electrical operation of hole quantum dot spin qubits is enabled by the strong Rashba spin-orbit coupling (SOC) originating from the intrinsic SOC in the Ge valence band as well as from the structural inversion asymmetry inherent in the underlying 2D hole gas. We use the atomistic valence force field (VFF) method to compute the strain due to random alloy disorder, and thermal expansion models in COMSOL Multiphysics to obtain the strain from a realistic gate-stack of planar hole quantum dot confinement. Recently, spin-orbit coupling terms \(\propto k\) have been shown to be induced by strain inhomogeneity. Our hybrid approach to realistic device modeling suggests that strain inhomogeneity due to both random alloy disorder and gate-induced strain make a strong contribution to the linear-\(k\) Dresselhaus spin-orbit coupling, which eventually dominates hole spin EDSR; and there exist specific in-plane orientations of the global magnetic field \(\mathbf{B}\) and the microwave drive \(\mathbf{\tilde{E}}_{\text{ac}}\) for maximum EDSR Rabi frequency of the hole spin qubit. The current model including strain inhomogeneity accurately predicts the EDSR Rabi frequency to be \(\!\sim\!100\) MHz for typical electric and magnetic fields in experiments, which represents at least an order of magnitude improvement in accuracy over phenomenological models assuming uniform uniaxial strain. State-of-the-art atomistic tight binding calculations via nano-electronic modeling (NEMO3D) are in agreement with the \(\mathbf{k}{\cdot}\mathbf{p}\) description.

arXiv:2502.06949 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)

Large thermoelectric spin-valve effect with a superconductor

New Submission | Superconductivity (cond-mat.supr-con) | 2025-02-12 20:00 EST

Pablo Tuero, Johanne Bratland Tjernshaugen, Carlos Sanchez, César Gonzalez-Ruano, Yuan Lu, Jacob Linder, Farkhad G. Aliev

Recent studies have revealed magnetically controllable thermoelectric effects in superconductor/ferromagnet (S/F) structures. A tunable cryogenic thermoelectric generator needs not only a high conversion factor between electricity and heat, but also a large change in the thermoelectric output when switching the magnetic state of the device. Here, we experimentally measure and numerically model thermoelectric effects in fully epitaxial F/S/F junctions based on commercially available, easily grown materials, as well as their dependence on the magnetic configuration of the F electrodes. We observe sizeable Seebeck coefficients for the parallel alignment of the ferromagnetic electrodes, reaching values of about \(100\)~\(\mu\)V/K. Importantly, we find a decrease of the thermoelectric signal of more than an order of magnitude when switching from a parallel to an antiparallel configuration, constituting a large thermoelectric spin-valve effect. Theoretical modeling based on a self-consistent non-equilibrium Keldysh-Usadel Green function theory, combined with micromagnetic simulations, qualitatively reproduce the experimental findings. These findings pave the way for the development of efficient and versatile cryogenic thermoelectric heat engines.

arXiv:2502.06962 (2025)

Superconductivity (cond-mat.supr-con)

Submitted for publication (Supplementary material included)

Many-body perturbation theory for moiré systems

New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-02-12 20:00 EST

Liangtao Peng, Giovanni Vignale, Shaffique Adam

Moiré systems such as magic-angle twisted bilayer graphene have attracted significant attention due to their ability to host correlated phenomena including superconductivity and strongly correlated insulating states. By defining the single-particle Green's function in the band basis, we systematically develop a many-body perturbation theory framework to address correlations beyond the usual mean-field Hartree-Fock approaches. As a specific example, we first analyze twisted bilayer graphene within the Hartree-Fock approximation. We derive analytical solutions for symmetry-breaking states at integer fillings and the finite-temperature metal-insulator transition that closely match previously known numerical results in the literature. Moving beyond Hartree-Fock, we incorporate self-consistent GW corrections demonstrating that first-order diagrams significantly overestimate the filling-dependent fluctuations in the electronic compressibility. This framework provides a comprehensive pathway for exploring strong electronic correlations in moiré systems beyond mean-field, giving new insights into the interplay of symmetry breaking and electron correlations.

arXiv:2502.06968 (2025)

Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

Vortex dynamics in the region of charge imbalance

New Submission | Superconductivity (cond-mat.supr-con) | 2025-02-12 20:00 EST

A. G. Sivakov, V. G. Volotskaya

The nature of vortex flows in the nonequilibrium region arising in the vicinity of phase-slip lines at the S-N boundary are investigated experimentally. It is shown that vortices continue to move when charge imbalance appears in a film that is in a dynamic mixed state. The vortex dynamics in this case is determined by the interaction of the vortices with only the superconducting component of the current. This statement is supported by a study of the dynamic mixed state in the nonequilibrium region near the S-N boundary.

arXiv:2502.06992 (2025)

Superconductivity (cond-mat.supr-con)

4 pages, 2 figures, postprint of Short Note published in Sov. J. Low Temp. Phys. (now AIP Low Temp. Phys.), see Preface therein

Sov. J. Low Temp. Phys. 11(5), 300-302 (1985)

Emergence of Order in Chemically Active Droplets: Temporal Dynamics and Collective Behavior

New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-02-12 20:00 EST

Sobiya Ashraf, Pawan Kumar, Prateek Dwivedi, Frédéric Blanc, Dipin Pillai, Rahul Mangal

Collective behaviors such as swarming, chemical signaling, and clustering are fundamental to biological microorganisms, enabling hierarchical colony formation, coordinated motion, and enhanced nutrient accessibility crucial for their survival. Over the past few decades, extensive research has been dedicated to unraveling the mechanisms underlying these diverse collective patterns through experimental model systems. Among these, active droplets have emerged as valuable synthetic analogs, effectively replicating key biological attributes and serving as ideal platforms for investigating collective phenomena. This research explores the collective behavior of 4-Cyano-4-pentyl-biphenyl (5CB) oil droplets across varying Péclet (\(Pe\)) numbers. At high \(Pe\), droplets exhibit a pusher mode of propulsion and form dynamic chain-like patterns. Decreasing \(Pe\) enhances repulsive interactions among droplets, resulting in the inhibition of clustering. In the low \(Pe\) regime, their repulsive interactions predominated by chemical field lead to the emergence of an ordered structure. Furthermore, we illustrate how active droplets efficiently navigate within a soft structured environment. These findings contribute to our comprehension of self-organized phenomena in active matter systems and provide insights for designing strategies for controlled locomotion in intricate fluidic environments.

arXiv:2502.07009 (2025)

Soft Condensed Matter (cond-mat.soft)

16 pages (12 main, 4 supporting), 12 figures (7 main, 5 supporting)

Interaction of Shear Horizontal Acoustic and Plasma Waves in Hexagonal Piezoelectric Semiconductors

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Qingguo Xia, Jianke Dua, Jiashi Yangb

We study coupled acoustic and plasma waves in piezoelectric semiconductor crystals of hexagonal symmetry. We focus on the so called shear-horizontal or antiplane motions with one mechanical displacement. A set of two dimensional equations is reduced from the three-dimensional equations. Since the material is effectively isotropic in the two dimensional plane under consideration, the equations are relatively simple. Dispersion curves of coupled elastic and acoustic waves are obtained analytically and examined numerically along with the effects of some parameters.

arXiv:2502.07023 (2025)

Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)

Shubnikov-de Haas oscillations in coherently strained AlN/GaN/AlN quantum wells on bulk AlN substrates

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Yu-Hsin Chen, Jimy Encomendero, Huili Grace Xing, Debdeep Jena

We report the observation of Shubnikov-de Haas (SdH) oscillations in coherently strained, low-dislocation AlN/GaN/AlN quantum wells (QWs), including both undoped and \(\delta\)-doped structures. SdH measurements reveal a single subband occupation in the undoped GaN QW and two subband occupation in the \(\delta\)-doped GaN QW. More importantly, SdH oscillations enable direct measurement of critical two-dimensional electron gas (2DEG) parameters at the Fermi level: carrier density and ground state energy level, electron effective mass (\(m^\ast \approx 0.289\,m_{\rm e}\) for undoped GaN QW and \(m^\ast \approx 0.298\,m_{\rm e}\) for \(\delta\)-doped GaN QW), and quantum scattering time (\(\tau_{\rm q} \approx 83.4 \, \text{fs}\) for undoped GaN QW and \(\tau_{\rm q} \approx 130.6 \, \text{fs}\) for \(\delta\)-doped GaN QW). These findings provide important insights into the fundamental properties of 2DEGs that are strongly quantum confined in the thin GaN QWs, essential for designing nitride heterostructures for high-performance electronic applications.

arXiv:2502.07032 (2025)

Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)

6 pages, 5 figures

Liquid crystalline structures formed by sphere-rod amphiphilic molecules in solvents

New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-02-12 20:00 EST

Nilanthi P. Haputhanthrige (1,2), Yifan Zhou (3), Jingfan Wei (3), Min Gao (1), Tianbo Liu (3), Oleg D. Lavrentovich (1,2) ((1) Advanced Materials and Liquid Crystal Institute, Kent State University, USA, (2) Department of Physics, Kent State University, USA, (3) School of Polymer Science and Polymer Engineering, The University of Akron, USA)

Self-assembly of amphiphilic molecules is an important phenomenon attracting a broad range of research. In this work, we study the self-assembly of KTOF4 sphere-rod amphiphilic molecules in mixed water-dioxane solvents. The molecules are of a T-shaped geometry, comprised of a hydrophilic spherical Keggin-type cluster attached by a flexible bridge to the center of a hydrophobic rod-like oligodialkylfluorene (OF), which consists of four OF units. Transmission electron microscopy (TEM) uncovers self-assembled spherical structures of KTOF4 in dilute solutions. These spheres are filled with smectic-like layers of KTOF4 separated by layers of the solution. There are two types of layer packings: (i) concentric spheres and (ii) flat layers. The concentric spheres form when the dioxane volume fraction in the solution is 35-50 vol%. The flat layers are formed when the dioxane volume fraction is either below (20 and 30 vol%.) or above (55 and 60 vol%.) the indicated range. The layered structures show no in-plane orientational order and thus resemble thermotropic smectic A liquid crystals and their lyotropic analogs. The layered packings reveal edge and screw dislocations. Evaporation of the solvent produces a bulk birefringent liquid crystal phase with textures resembling the ones of uniaxial nematic liquid crystals. These findings demonstrate that sphere-rod molecules produce a variety of self-assembled structures that are controlled by the solvent properties.

arXiv:2502.07037 (2025)

Soft Condensed Matter (cond-mat.soft)

This article has 21 pages, 7 figures and one Table

Operation of a high-frequency, phase-slip qubit

New Submission | Superconductivity (cond-mat.supr-con) | 2025-02-12 20:00 EST

Cheeranjeev Purmessur, Kaicheung Chow, Bernard van Heck, Angela Kou

Aluminum-based Josephson junctions are currently the main sources of nonlinearity for control and manipulation of superconducting qubits. A phase-slip junction, the dual of a Josephson junction, provides an alternative source of nonlinearity that promises new types of protected qubits and the possibility of high-temperature and high-frequency operation through the use of superconductors with larger energy gaps. Phase-slip junctions have been challenging, however, to incorporate into superconducting qubits because of difficulty controlling junction parameters. Here we demonstrate the operation of a superconducting qubit based on a phase slip junction made using titanium nitride. We operate the qubit at zero flux where the qubit frequency (~17 GHz) is mainly determined by the inductance of the qubit. We perform readout and coherent control of the superconducting qubit, and measure qubit lifetimes >60 \(\mu\)s. Finally, we demonstrate operation of the qubit at temperatures exceeding 300 mK. Our results add the phase-slip junction as a tool for superconducting quantum information processing and opens avenues for new classes of superconducting qubits.

arXiv:2502.07043 (2025)

Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)

On the use of neural networks for the structural characterization of polymeric porous materials

New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-02-12 20:00 EST

Jorge Torre, Suset Barroso-Solares, M.A. Rodríguez-Pérez, Javier Pinto

The structural characterization is an essential task in the study of porous materials. To achieve reliable results, it requires to evaluate images with hundreds of pores. Current methods require large time amounts and are subjected to human errors and subjectivity. A completely automatic tool would not only speed up the process but also enhance its reliability and reproducibility. Therefore, the main objective of this article is the study of a deep-learning-based technique for the structural characterization of porous materials, through the use of a convolutional neural network. Several fine-tuned Mask R CNN models are evaluated using different training configurations in four separate datasets each composed of numerous SEM images of diverse polymeric porous materials: closed-pore extruded polystyrene (XPS), polyurethane (PU), and poly(methyl methacrylate) (PMMA), and open-pore PU. Results prove the tool capable of providing very accurate results, equivalent to those achieved by time consuming manual methods, in a matter of seconds.

arXiv:2502.07076 (2025)

Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Computer Vision and Pattern Recognition (cs.CV), Image and Video Processing (eess.IV)

Polymer, Volume 291, 2024, 126597

Pairing phase diagram for electron-doped cuprates in the square-lattice \(t-U-V\) Hubbard model

New Submission | Superconductivity (cond-mat.supr-con) | 2025-02-12 20:00 EST

Zhangkai Cao, Shuning Tan, Ji Liu, Xiaosen Yang, Tao Ying, Ho-Kin Tang, Cho-Tung Yip

Motivated by significant discrepancies between experimental observations of electron-doped cuprates and numerical results of the Hubbard model, we investigate the role of nearest-neighbor (NN) electron interactions \(V\) by studying the \(t-U-V\) model on square lattices. Upon doping \(\delta\)= 0.153, by using constrained path quantum Monte Carlo (CPQMC) method, we find that NN electron attraction \(V\) can notably drive an exotic \(p\)-wave spin-triplet pairing, while the NN electron repulsion \(V\) will suppress the \(d_{x^2-y^2}\)-wave (\(d\)-wave) pairing and triggers the \(d_{xy}\)-wave pairing. Especially in the intermediate coupling regime, as NN repulsion increases, the intensity of \(d_{xy}\)-wave pairing also increases, further suppressing the presence of \(d\)-wave pairing, which may help explain the notable suppression of \(d\)-wave pairing in electron-doped cuprate superconductors. Besides the pairing phase, we also find that the NN electron attraction \(V\) has no significant effect on spin density wave (SDW) and charge density wave (CDW), but repulsion \(V\) significantly enhanced CDW and suppressed SDW. Our study suggests the \(t-U-V\) Hubbard model can serve as the minimal model to capture the essential physics of the electron-doped cuprates. Notably, for \(V/U \sim 1/4 - 1/3\), the results align more closely with the experimentally observed behavior of electron-doped systems, potentially explaining the shrinkage of \(d\)-wave superconductivity region and the decrease of superconducting temperature.

arXiv:2502.07079 (2025)

Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)

7 pages, 5 figures

Majorana quasiparticles in atomic spin chains on superconductors

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Stephan Rachel, Roland Wiesendanger

For the past decade, Majorana quasiparticles have become one of the hot topics in condensed matter research. Besides the fundamental interest in the realization of particles being their own antiparticles, going back to basic concepts of elementary particle physics, Majorana quasiparticles in condensed matter systems offer exciting potential applications in topological quantum computation due to their non-Abelian quantum exchange statistics. Motivated by theoretical predictions about possible realizations of Majorana quasiparticles as zero-energy modes at boundaries of topological superconductors, experimental efforts have focussed in particular on quasi-one-dimensional semiconductor-superconductor and magnet-superconductor hybrid systems. However, an unambiguous proof of the existence of Majorana quasiparticles is still challenging and requires considerable improvements in materials science, atomic-scale characterization and control of interface quality, as well as complementary approaches of detecting various facets of Majorana quasiparticles. Bottom-up atom-by-atom fabrication of disorder-free atomic spin chains on atomically clean superconducting substrates has recently allowed deep insight into the emergence of topological sub-gap Shiba bands and associated Majorana states from the level of individual atoms up to extended chains, thereby offering the possibility for critical tests of Majorana physics in disorder-free model-type 1D hybrid systems.

arXiv:2502.07089 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)

28 pages, 17 figures, 4 info boxes

Physics Reports 1099, 1-28 (2025)

Density Functional Tight-Binding Captures Plasmon-Driven H\(_2\) Dissociation on Al Nanocrystals

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Nikhil S. Chellam, George C. Schatz

Aluminum nanocrystals offer a promising platform for plasmonic photocatalysis, yet a detailed understanding of their electron dynamics and consequent photocatalytic performance has been challenging thus far due to computational limitations. Here, we employ density functional tight-binding methods (DFTB) to investigate the optical properties and H₂ dissociation dynamics of Al nanocrystals with varying sizes and geometries. Our real-time simulations reveal that Al's unique free-electron nature enables efficient light-matter interactions and rapid electronic thermalization. Cubic and octahedral nanocrystals ranging from 0.5 to 4.5 nm exhibit size-dependent plasmon resonances in the UV, with distinct spectral features arising from the particle geometry and electronic structure. By simulating H₂ dissociation near Al nanocrystals, we demonstrate that hot electrons generated through plasmon excitation can overcome the molecule's strong chemical bond within tens of femtoseconds. The laser intensity threshold is comparable to previous reports for Ag nanocrystals, though significantly lower than that of Au. Notably, the dipolar plasmon mode demonstrates higher efficiency for this reaction than the localized interband transition for particles at these sizes. Taken together, this work provides mechanistic insights into plasmon-driven catalysis and showcases DFTB's capability to study quantum plasmonics at unprecedented length and time scales.

arXiv:2502.07094 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

Uncertainty Quantification for Misspecified Machine Learned Interatomic Potentials

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Danny Perez, Aparna P. A. Subramanyam, Ivan Maliyov, Thomas D. Swinburne

The use of high-dimensional regression techniques from machine learning has significantly improved the quantitative accuracy of interatomic potentials. Atomic simulations can now plausibly target quantitative predictions in a variety of settings, which has brought renewed interest in robust means to quantify uncertainties on simulation results. In many practical settings, encompassing both classical and a large class of machine learning potentials, the dominant form of uncertainty is currently not due to lack of training data but to misspecification, namely the inability of any one choice of model parameters to exactly match all ab initio training data. However, Bayesian inference, the most common formal tool used to quantify uncertainty, is known to ignore misspecification and thus significantly underestimates parameter uncertainties. Here, we employ a recent misspecification-aware regression technique to quantify parameter uncertainties, which is then propagated to a broad range of phase and defect properties in tungsten via brute force resampling or implicit differentiation. The propagated misspecification uncertainties robustly envelope errors to direct calculation of material properties outside of the training dataset, an essential requirement for any quantitative multi-scale modeling scheme. Finally, we demonstrate application to recent foundational machine learning interatomic potentials, accurately predicting and bounding errors in MACE-MPA-0 energy predictions across the diverse materials project database. Perspectives for the approach in multiscale simulation workflows are discussed.

arXiv:2502.07104 (2025)

Materials Science (cond-mat.mtrl-sci)

Towards MatCore: A Unified Metadata Standard for Materials Science

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Jane Greenberg, Pamela Boveda-Aguirre, John Allison, Pietro Asinari, Maria Chan, Anand Chandrasekaran, Elif Ertekin, Emmanouel Garoufallou, Giulia Galli, Paolo Giannozzi, Feliciano Giustino, Gerhard Goldbeck, Hendrik Heinz, Arthi Jayaraman, Vincenzo Lordi, Kristin A. Persson, Gian-Marco Rignanese, Aidan Thompson, Eric Toberer, Scott McClellan, Ellad B. Tadmor

The materials science community seeks to support the FAIR principles for computational simulation research. The MatCore Project was recently launched to address this need, with the goal of developing an overall metadata framework and accompanying guidelines. This paper reports on the MatCore goals and overall progress. Historical background context is provided, including a review of the principles underlying successful core metadata standards. The paper also presents selected MatCore examples and discusses future plans.

arXiv:2502.07106 (2025)

Materials Science (cond-mat.mtrl-sci)

11 pages, 5 figures, Conference Paper

Detection of chiral spin fluctuations driven by frustration in Mott insulators

New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-02-12 20:00 EST

Kuan H. Hsu, Chunjing Jia, Emily Z. Zhang, Daniel Jost, Brian Moritz, Rudi Hackl, Thomas P. Devereaux

Topologically ordered states, such as chiral spin liquids, have been proposed as candidates that host fractionalized excitations. However, detecting chiral character or proximity to these non-trivial states remains a challenge. Resonant Raman scattering can be a powerful tool for detecting chiral fluctuations, as the \(A_{2g}\) channel probes excitations with broken time-reversal symmetry and local chiral order. Here, we use exact diagonalization to characterize the resonant \(A_{2g}\) channel, alongside two-magnon scattering in \(B_{1g}\) and \(E_g\) channels, for the Hubbard model on lattices with increasing levels of geometric spin frustration, where tuning the incident energy near the Mott gap reveals strong chiral spin excitation intensity. Increased spin frustration in the Mott insulator results in an overall softening of the Raman \(A_{2g}\) response, indicating a tendency toward low energy chiral-chiral fluctuations in Mott insulators with magnetic frustration and proximity to chiral spin liquid states that can potentially be tuned by external perturbations.

arXiv:2502.07108 (2025)

Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)

7+5 pages, 6+3 figures

Anisotropic resonance energy transfer with strained phosphorene

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

J. Oliveira-Cony, C. Farina, P. P. Abrantes, Tarik P. Cysne

We analyze the resonance energy transfer (RET) rate between quantum emitters (QEs) near a phosphorene/SiC interface under the effects of uniaxial strain. Using a low-energy tight-binding model, we describe the electronic structure of strained phosphorene in an experimentally feasible situation. Due to the anisotropic electronic structure of phosphorene, we demonstrate that the RET rate drastically depends on the direction in which the QEs are separated relative to the phosphorene lattice. More specifically, we obtain a large variation in the RET rate when the QEs are separated along the zigzag direction, in contrast to a rather small variation when separated along the armchair direction of phosphorene's crystalline structure. Furthermore, our results reveal that the RET rate can be highly modulated by uniaxial strain in phosphorene when considering emitters placed along the zigzag direction. Finally, by means of a simple toy model, we also show that this anisotropy in the RET rate is a general characteristic produced by anisotropic 2D materials.

arXiv:2502.07121 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics), Quantum Physics (quant-ph)

Weyl semimetal phases and intrinsic spin-Hall conductivity in SbAs ordered alloys

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Muhammad Zubair, Dai Q. Ho, Duy Quang To, Shoaib Khalid, Anderson Janotti

Using density functional theory calculations we investigated possible Weyl semimetal (WSM) phases in antimony arsenide ordered alloys Sb1-xAsx (x=0, 1/6, 1/3, 1/2, 2/3, 5/6, 1). We find WSM phases for all As compositions of Sb1-xAsx with broken inversion symmetry, in contrast to Bi1-xSbx where only compositions x=1/2 and 5/6 were predicted to exhibit WSM phases. The WSM phases in Sb1-xAsx are characterized by the presence of 12 Weyl points, located within 55 meV from the Fermi level in the case of x=1/2. The robust spin-orbit coupling strength and Berry curvature in these alloys produce large spin-Hall conductivity in the range of 176-602 (hbar/e)(S/cm), comparable to that in the BiSb alloys. Finally, Sb0.5As0.5 is predicted to be almost lattice-matched to GaAs(111), with the Fermi level within the gap of the semiconductor, facilitating growth and characterization, and thus, offering promising integration with conventional semiconductors.

arXiv:2502.07147 (2025)

Materials Science (cond-mat.mtrl-sci)

An Unconventional Ultra-Sub-Wavelength Receiving Nano-Antenna Activated by ac Spin Pumping and the ac Inverse Spin Hall Effect

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Raisa Fabiha, Michael Suche, Erdem Topsakal, Supriyo Bandyopadhyay

We report an extreme sub-wavelength unconventional receiving antenna. It consists of an array of nanomagnets connected to heavy metal nanostrips. Incident electromagnetic (EM) radiation generates intrinsic and extrinsic spin waves in the nanomagnets, which pump spin into the heavy metal nanostrips at their own frequencies giving rise to a polychromatic alternating voltage across the latter owing to the ac inverse spin Hall effect. This implements a receiving nano-antenna. We demonstrate its operation at two different EM wave frequencies of 1.5 GHz and 2.4 GHz - the latter being the Bluetooth and Wi-Fi frequency. We measure the receiving gain at 2.4 GHz to be approximately -9 db. The free space radiated wavelength "lambda" at 2.4 GHz is 12.5 cm while the antenna area A is merely 160 micron^2, making the ratio A/lambda^2 = 0.97x10^-8. This antenna's receiving gain should be very poor because of the tiny size. Yet the measured gain is more than 4000 times larger than the theoretical limit for a conventional antenna of this size at this wavelength because of the unconventional operating principle.

arXiv:2502.07162 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Signal Processing (eess.SP)

Efficient First-Principles Framework for Overdamped Phonon Dynamics and Anharmonic Electron-Phonon Coupling in Superionic Materials

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Yuxuan Wang, Marios Zacharias, Xiao Zhang, Nick Pant, Jacky Even, Pierre F. P. Poudeu, Emmanouil Kioupakis

Relying on the anharmonic special displacement method, we introduce an ab initio quasistatic polymorphous framework to describe local disorder, anharmonicity, and electron-phonon coupling in superionic conductors. Using the example of cubic Cu2Se, we show that positional polymorphism yields extremely overdamped anharmonic vibrations while preserving transverse acoustic phonons, consistent with experiments. We also demonstrate well-defined electronic band structures with large band gap openings due to polymorphism of 1.0 eV and calculate anharmonic electron-phonon renormalization, yielding band gap narrowing with increasing temperature in agreement with previous measurements. Our approach opens the way for efficient ab initio electronic structure calculations in superionic crystals to elucidate their compelling high figure-of-merit.

arXiv:2502.07217 (2025)

Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)

Impact of Annealing Temperature on the Energy Storage Performance of CoO2 Nanoparticles Synthesized via Solid State Reaction

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Shoaib Akram, Muneeb ur Rahman, Fazli Maula, Osama Tariq Satti, Shahbaz Afzal, Fawad Ali

The solid-state reaction was used to synthesize CoO2 nanostructured material. Cobalt nitrate tetrahydrate and sodium oxide (NaOH) were combined to produce CoO2 nanostructured material. The three synthesized working electrodes were each tested individually, using 3 M KOH as the electrolyte. The CV analysis of a three-electrode system revealed redox peaks, indicating Faradaic processes. The estimated specific capacitances of CoO2, CoO2 (250oC), CoO2 (300oC) nanostructured material at scan rates of (10) mVs-1 is (223, 348, and 473) Fg-1. The diffraction peaks at 2{} = 26.264o, 33.527o, 37.579, 51.264 and 54.367o correspond respectively to the diffraction planes of 111, 112, 200, 211, and 311 of CoO2 nanostructured material. The annealing temperature, which affects the bandgap, can influence the size, shape, and crystallinity of nanostructures. For the unannealed material, the energy bandgap of CoO2 is 2.00 eV, whereas for the annealed material it ranges from 1.77 to 1.86 eV.

arXiv:2502.07227 (2025)

Materials Science (cond-mat.mtrl-sci)

16 pages, 6 figures

Non-linear integral equations for the XXX spin-1/2 quantum chain with non-diagonal boundary fields

New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-02-12 20:00 EST

Holger Frahm, Andreas Klümper, Dennis Wagner, Xin Zhang

The XXX spin-\(\frac{1}{2}\) Heisenberg chain with non-diagonal boundary fields represents a cornerstone model in the study of integrable systems with open boundaries. Despite its significance, solving this model exactly has remained a formidable challenge due to the breaking of \(U(1)\) symmetry. Building on the off-diagonal Bethe Ansatz (ODBA), we derive a set of nonlinear integral equations (NLIEs) that encapsulate the exact spectrum of the model. For \(U(1)\) symmetric spin-\(\frac{1}{2}\) chains such NLIEs involve two functions \(a(x)\) and \(\bar{a}(x)\) coupled by an integration kernel with short-ranged elements. The solution functions show characteristic features for arguments at some length scale which grows logarithmically with system size \(N\). For the non \(U(1)\) symmetric case, the equations involve a novel third function \(c(x)\), which captures the inhomogeneous contributions of the \(T\)-\(Q\) relation. The kernel elements coupling this function to the standard ones are long-ranged and lead for the ground-state to a winding phenomenon. In \(\log(1+a(x))\) and \(\log(1+\bar a(x))\) we observe a sudden change by \(2\pi\)i at a characteristic scale \(x_1\) of the argument. Other features appear at a value \(x_0\) which is of order \(\log N\). These two length scales, \(x_1\) and \(x_0\), are independent: their ratio \(x_1/x_0\) is large for small \(N\) and small for large \(N\). Explicit solutions to the NLIEs are obtained numerically for these limiting cases, though intermediate cases (\(x_1/x_0 \sim 1\)) present computational challenges. This work lays the foundation for studying finite-size corrections and conformal properties of other integrable spin chains with non-diagonal boundaries, opening new avenues for exploring boundary effects in quantum integrable systems.

arXiv:2502.07229 (2025)

Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th)

15 pages, 3 figures

Hund flat band in a frustrated spinel oxide

New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-02-12 20:00 EST

Dongjin Oh, Alexander Hampel, Joshua P. Wakefield, Peter Moen, Steef Smit, Xiangyu Luo, Marta Zonno, Sergey Gorovikov, Mats Leandersson, Craig Polley, Asish K. Kundu, Anil Rajapitamahuni, Elio Vescovo, Chris Jozwiak, Aaron Bostwick, Eli Rotenberg, Masahiko Isobe, Manish Verma, Matteo Crispino, Martin Grundner, Fabian B. Kugler, Oliver Parcollet, Ulrich Schollwöck, Hidenori Takagi, Andrea Damascelli, Giorgio Sangiovanni, Joseph G. Checkelsky, Antoine Georges, Riccardo Comin

Electronic flat bands associated with quenched kinetic energy and heavy electron mass have attracted great interest for promoting strong electronic correlations and emergent phenomena such as high-temperature charge fractionalization and superconductivity. Intense experimental and theoretical research has been devoted to establishing the rich non-trivial metallic and heavy fermion phases intertwined with such localized electronic states. Here, we investigate the transition metal oxide spinel LiV2O4, an enigmatic heavy fermion compound lacking localized f orbital states. We use angle-resolved photoemission spectroscopy and dynamical mean field theory to reveal a new kind of correlation-induced flat band with suppressed inter-atomic electron hopping arising from intra-atomic Hund coupling. The appearance of heavy quasiparticles is ascribed to a proximate orbital-selective Mott state characterized by fluctuating local moments as evidenced by complementary magnetotransport measurements. The spectroscopic fingerprints of long-lived quasiparticles and their disappearance with increasing temperature further support the emergence of a high-temperature bad metal state observed in transport data. This work resolves a long-standing puzzle on the origin of heavy fermion behavior and unconventional transport in LiV2O4. Simultaneously, it opens a new path to achieving flat bands through electronic interactions in d-orbital systems with geometrical frustration, potentially enabling the realization of exotic phases of matter such as the fractionalized Fermi liquids.

arXiv:2502.07234 (2025)

Strongly Correlated Electrons (cond-mat.str-el)

21 pages, 4 figures

The Sand Atlas

New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-02-12 20:00 EST

Ilija Vego, Benjy Marks

The Sand Atlas is a publicly accessible repository dedicated to the collection, processing, and sharing of high-resolution 3D models of sand-sized particles. This dataset offers valuable insights into the morphology of a wide variety of natural and synthetic sand-sized particles from different regions, with varying mineralogy and history. The primary goal of The Sand Atlas is to support researchers, educators, and industry professionals by providing detailed, easily accessible and uniformly produced surface meshes and level-set data. The underlying code that converts volumetric data to meshes is also available via the sand-atlas python package. This platform encourages community participation, inviting contributors to share their own data and enrich the collective understanding of granular materials.

arXiv:2502.07235 (2025)

Soft Condensed Matter (cond-mat.soft)

CO2 adsorption mechanisms in hydrated silica nanopores: Insights from grand canonical Monte Carlo to classical and ab initio molecular dynamics

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Jihong Shi, Tao Zhang, Shuyu Sun, Liang Gong

Understanding interfacial phenomena in confined systems is important for optimizing CO2 capture technologies. Here, we present a comprehensive investigation of CO2 adsorption in hydrated amorphous silica nanopores through an integrated computational approach combining grand canonical Monte Carlo (GCMC), classical molecular dynamics (MD), and ab initio molecular dynamics (AIMD) simulations. The excess adsorption isotherms reveal a marked hydration dependence, with CO2 uptake decreasing from 7.6 to 2.6 mmol/g as water content increases from 1 to 15 wt%. Analysis of adsorption kinetics demonstrates a distinctive bimodal process, characterized by rapid initial uptake followed by slower diffusion-limited adsorption, with the latter becoming increasingly dominant at higher hydration levels. Classical MD simulations reveal an inverse correlation between hydration and CO2 mobility, with self-diffusion coefficients decreasing across the studied hydration range. Density profile analysis indicates a hydration-induced transition in CO2 distribution from central pore regions to surface-proximate domains, accompanied by restructuring of interfacial water networks. Notably, AIMD simulations capture previously unrecognized chemical processes, including proton transfer mechanisms leading to surface silanol formation with characteristic O-O distances of 2.4-2.5 Å, and spontaneous CO2 hydration yielding carbonate species through water-mediated reaction pathways. These findings demonstrate the dual role of confined water as both a spatial competitor and reaction medium for CO2 capture, providing molecular-level insights with quantum mechanical accuracy for design of carbon capture materials.

arXiv:2502.07251 (2025)

Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)

10 pages, 6 figures

Finite-Temperature Kinetic Ferromagnetism in the Square Lattice Hubbard Model

New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-02-12 20:00 EST

Robin C. Newby, Ehsan Khatami

While the exact phase diagram of the Fermi-Hubbard model remains poorly understood despite decades of progress, nearly 60 years ago, Nagaoka proved that a single dopant in an otherwise half-filled Hubbard system can bring about ferromagnetism through kinetic means. The phenomenon was recently observed with ultracold atoms in triangular optical lattices. Here, we explore the kinetic ferromagnetism within the square lattice Hubbard model and its strong-coupling counterpart, the \(t-J\) model, at finite temperatures in the thermodynamic limit via numerical linked-cluster expansions. We find evidence of ferromagnetic Nagaoka polarons at dopings up to \(\sim 30\%\) away from half filling for a variety of interaction strengths and at temperatures as low as \(0.2\) of the hopping energy. We map out the boundaries of this phase through analyzing various correlation functions.

arXiv:2502.07252 (2025)

Strongly Correlated Electrons (cond-mat.str-el), Quantum Gases (cond-mat.quant-gas)

9 pages, 10 figures

Comprehensive numerical analysis of doping controlled efficiency in lead free Cs(SnGe)I3 perovskites

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Nazmul Hasan, M. Hussayeen Khan Anik, Mohammed Mehedi Hasan, Sharnali Islam, Alamgir Kabir

One effective way to prevent toxicity and improve the stability of materials for photovoltaic applications is to exclude lead and organic molecules from perovskite materials. Specifically, the CsSn1-xGexI3 appears to be a promising contender; nonetheless, it requires optimization, particularly bandgap tuning by doping concentration modifications. In this study, density functional theory (DFT) was employed to comprehensively analyze the electronic properties of CsSn1-xGexI3 that influenced light-matter interactions tuning of the perovskite materials by varying composition in B site atoms. We use the solar cell capacitance (SCAPS-1D) simulator to compute device performance; however, it computes the absorption spectrum using a simplified mathematical function that approximates the actual spectrum. To achieve a quantum-mechanical level of accuracy DFT extracted parameters like absorption spectra and bandgap were fed into SCAPS-1D. We find that increasing the Ge concentration leads to a higher bandgap and improved absorption profile, thereby enhancing solar energy conversion efficiency. Thermal and field distribution analyses were also done for the optimized device through a finite-difference time-domain (FDTD) framework. By optimizing the absorber layer with a 75% Ge concentration, we achieve a remarkable PCE of 23.80%. Our findings guide future research in designing high-performance non-leaded halide PSCs, paving the way for low-cost, stable, and highly efficient solar cells through atomic doping-tuned perovskite absorber layers.

arXiv:2502.07260 (2025)

Materials Science (cond-mat.mtrl-sci)

Magnetic Bloch States at Integer Flux Quanta Induced by Super-moiré Potential in Graphene Aligned with Twisted Boron Nitride

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Yaqi Ma, Meizhen Huang, Xu Zhang, Weixiong Hu, Zishu Zhou, Kai Feng, Wenhui Li, Yong Chen, Chenxuan Lou, Weikang Zhang, Haoxi Ji, Yibo Wang, Zefei Wu, Xiaodong Cui, Wang Yao, Shichao Yan, Zi Yang Meng, Ning Wang

Two-dimensional electron systems in both magnetic fields and periodic potentials are described by Hofstadter butterfly, a fundamental problem of solid-state this http URL moiré systems provide a powerful method to realize this spectrum, previous experiments, however, have been limited to fractional flux quanta regime due to the difficulty of building ~ 50 nm periodic this http URL, we demonstrate a super-moiré strategy to overcome this challenge. By aligning monolayer graphene (G) with 1.0° twisted hexagonal boron nitride (t-hBN), a 63.2 nm bichromatic G/t-hBN super-moiré is constructed, made possible by exploiting the electrostatic nature of t-hBN this http URL magnetic field B, magnetic Bloch states at integer flux quanta (1-9) are achieved and observed as integer Brown-Zak oscillations, expanding the flux quanta from factions to this http URL analysis reproduces these experimental findings. This work opens new avenues to study unexplored Hofstadter butterfly, explore emergent topological order at integer flux quanta and engineer long-wavelength periodic modulations.

arXiv:2502.07283 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

15 pages, 4 figures

Global Universal Scaling and Ultra-Small Parameterization in Machine Learning Interatomic Potentials with Super-Linearity

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Yanxiao Hu, Ye Sheng, Jing Huang, Xiaoxin Xu, Yuyan Yang, Mingqiang Zhang, Yabei Wu, Caichao Ye, Jiong Yang, Wenqing Zhang

Using machine learning (ML) to construct interatomic interactions and thus potential energy surface (PES) has become a common strategy for materials design and simulations. However, those current models of machine learning interatomic potential (MLIP) provide no relevant physical constrains, and thus may owe intrinsic out-of-domain difficulty which underlies the challenges of model generalizability and physical scalability. Here, by incorporating physics-informed Universal-Scaling law and nonlinearity-embedded interaction function, we develop a Super-linear MLIP with both Ultra-Small parameterization and greatly expanded expressive capability, named SUS2-MLIP. Due to the global scaling rooting in universal equation of state (UEOS), SUS2-MLIP not only has significantly-reduced parameters by decoupling the element space from coordinate space, but also naturally outcomes the out-of-domain difficulty and endows the potentials with inherent generalizability and scalability even with relatively small training dataset. The nonlinearity-enbeding transformation for interaction function expands the expressive capability and make the potentials super-linear. The SUS2-MLIP outperforms the state-of-the-art MLIP models with its exceptional computational efficiency especially for multiple-element materials and physical scalability in property prediction. This work not only presents a highly-efficient universal MLIP model but also sheds light on incorporating physical constraints into artificial-intelligence-aided materials simulation.

arXiv:2502.07293 (2025)

Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)

PICTS: A Novel Deep Reinforcement Learning Approach for Dynamic P-I Control in Scanning Probe Microscopy

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Ziwei Wei, Shuming Wei, Qibin Zeng, Wanheng Lu, Huajun Liu, Kaiyang Zeng

We have developed a Parallel Integrated Control and Training System, leveraging the deep reinforcement learning to dynamically adjust the control strategies in real time for scanning probe microscopy techniques.

arXiv:2502.07326 (2025)

Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG), Applied Physics (physics.app-ph)

21 pages, 6 figures

Auxiliary dynamical mean-field approach for Anderson-Hubbard model with off-diagonal disorder

New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-02-12 20:00 EST

Zelei Zhang, Jiawei Yan, Li Huang, Youqi Ke

This work reports a theoretical framework that combines the auxiliary coherent potential approximation (ACPA-DMFT) with dynamical mean-field theory to study strongly correlated and disordered electronic systems with both diagonal and off-diagonal disorders. In this method, by introducing an auxiliary coupling space with extended local degree of freedom,the diagonal and off-diagonal disorders are treated in a unified and self-consistent framework of coherent potential approximation, within which the dynamical mean-field theory is naturally combined to handle the strongly correlated Anderson-Hubbard model. By using this approach, we compute matsubara Green's functions for a simple cubic lattice at finite temperatures and derive impurity spectral functions through the maximum entropy method. Our results reveal the critical influence of off-diagonal disorder on Mott-type metal-insulator transitions. Specifically, a reentrant phenomenon is identified, where the system transitions between insulating and metallic states under varying interaction strengths. The ACPA-DMFT method provides an efficient and robust computational method for exploring the intricate interplay of disorder and strong correlations.

arXiv:2502.07353 (2025)

Strongly Correlated Electrons (cond-mat.str-el), Computational Physics (physics.comp-ph), Quantum Physics (quant-ph)

Floquet-Volkov interference in a semiconductor

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Changhua Bao, Haoyuan Zhong, Benshu Fan, Xuanxi Cai, Fei Wang, Shaohua Zhou, Tianyun Lin, Hongyun Zhang, Pu Yu, Peizhe Tang, Wenhui Duan, Shuyun Zhou

Intense light-field can dress both Bloch electrons inside crystals and photo-emitted free electrons in the vacuum, dubbed as Floquet and Volkov states respectively. These quantum states can further interfere coherently, modulating light-field dressed states. Here, we report experimental evidence of the Floquet-Volkov interference in a semiconductor - black phosphorus. A highly asymmetric modulation of the spectral weight is observed for the Floquet-Volkov states, and such asymmetry can be further controlled by rotating the pump polarization. Our work reveals the quantum interference between different light-field dressed electronic states, providing insights for material engineering on the ultrafast timescale.

arXiv:2502.07357 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)

Phys. Rev. B 111, L081106 (2025)

Colloidal Model for Investigating Optimal Efficiency in Weakly Coupled Ratchet Motors

New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-02-12 20:00 EST

José Martín-Roca, Laura Izquierdo-Solís, Fernando Martínez-Pedrero, Pau Casadejust, Ignacio Pagonabarraga, Carles Calero

We investigate the transport of superparamagnetic colloidal particles along self-assembled tracks using a periodically applied magnetic field as a model for ratchet-like mechanisms. Through video microscopy and simulations, we examine how factors such as particle size, track roughness, and the shape, intensity, and frequency of the applied potential influence transport efficiency. The findings reveal that processive motion can be achieved without residual attraction, with optimal transport efficiency governed by the combined effects of particle size ratios, actuation frequency, track roughness, and asymmetry in the applied potential. Additionally, we explore alternative strategies, including weak residual attraction and alternating magnetic fields, to further enhance efficiency. These findings provide valuable insights for the development of synthetic micro/nanomotors with potential applications in drug delivery and environmental remediation.

arXiv:2502.07362 (2025)

Soft Condensed Matter (cond-mat.soft)

Ultrafast dynamics of moments in bulk ferromagnets

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Mouad Fattouhi, Pascal Thibaudeau, Liliana D. Buda-Prejbeanu

A robust and efficient model for investigating the ultrafast dynamics of magnetic materials excited by laser pulses has been created, integrating dynamic Landau-Lifshitz-Bloch equations with a quantum thermostat and a two-temperature model. The model has been successfully applied to three archetypal materials in the literature: nickel, cobalt, and iron. Additionally, analysis of the ultrafast dynamic susceptibility tensor indicates that off-diagonal components display specific features depending on whether a continuous external magnetic field is present.

arXiv:2502.07375 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)

main: 19 pages, 3 figures. Supplemental: 3 pages, 2 figures

Explainable Multimodal Machine Learning for Revealing Structure-Property Relationships in Carbon Nanotube Fibers

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Daisuke Kimura, Naoko Tajima, Toshiya Okazaki, Shun Muroga

In this study, we propose Explainable Multimodal Machine Learning (EMML), which integrates the analysis of diverse data types (multimodal data) using factor analysis for feature extraction with Explainable AI (XAI), for carbon nanotube (CNT) fibers prepared from aqueous dispersions. This method is a powerful approach to elucidate the mechanisms governing material properties, where multi-stage fabrication conditions and multiscale structures have complex influences. Thus, in our case, this approach helps us understand how different processing steps and structures at various scales impact the final properties of CNT fibers. The analysis targeted structures ranging from the nanoscale to the macroscale, including aggregation size distributions of CNT dispersions and the effective length of CNTs. Furthermore, because some types of data were difficult to interpret using standard methods, challenging-to-interpret distribution data were analyzed using Negative Matrix Factorization (NMF) for extracting key features that determine the outcome. Contribution analysis with SHapley Additive exPlanations (SHAP) demonstrated that small, uniformly distributed aggregates are crucial for improving fracture strength, while CNTs with long effective lengths are significant factors for enhancing electrical conductivity. The analysis also identified thresholds and trends for these key factors to assist in defining the conditions needed to optimize CNT fiber properties. EMML is not limited to CNT fibers but can be applied to the design of other materials derived from nanomaterials, making it a useful tool for developing a wide range of advanced materials. This approach provides a foundation for advancing data-driven materials research.

arXiv:2502.07400 (2025)

Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft), Artificial Intelligence (cs.AI), Machine Learning (cs.LG), Data Analysis, Statistics and Probability (physics.data-an)

33 pages, 9 figures

Origins of the anomalous Hall conductivity in the symmetry enforced Fe3GeTe2 nodal-line ferromagnet

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Mikel García-Díez, Haim Beidenkopf, Iñigo Robredo, Maia G. Vergniory

Fe\(_3\)GeTe\(_2\) has gained attention in the condensed matter community for its potential to be exfoliated into thin films with ferromagnetic (FM) order, thanks to its van der Waals layered structure and significant intrinsic anomalous Hall conductivity (AHC). In this work, we analyze the electronic structure and show that, contrary to prior claims, the bulk of the AHC cannot arise from gapped nodal lines. By studying the material's symmetry properties, both with and without spin-orbit coupling (SOC) and across paramagnetic and FM phases, we find that Fe\(_3\)GeTe\(_2\) hosts mirror-symmetry-protected nodal lines, which support surface drumhead states. Additionally, we identify three key sources of AHC: nodal lines in the paramagnetic phase gapped by the FM order, Weyl points within specific energy ranges, and gaps between spin-up and spin-down bands caused by SOC. Finally, our calculations suggest that electron doping could increase the AHC up to four times compared to its value at the computed Fermi level.

arXiv:2502.07420 (2025)

Materials Science (cond-mat.mtrl-sci)

10 pages, 8 figures

Non-adiabaticity from first principles: the exact-factorization approach for solids

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Galit Cohen, Rachel Steinitz-Eliyahu, E. K. U. Gross, Sivan Refaely-Abramson, Ryan Requist

The thorough treatment of electron-lattice interactions from first principles is one of the main goals in condensed matter physics. While the commonly applied adiabatic Born-Oppenheimer approximation is sufficient for describing many physical phenomena, it is limited in its ability to capture meaningful features originating from non-adiabatic coupling effects. The exact factorization method, starting from the full Hamiltonian of electrons and nuclei, provides a way to systematically account for non-adiabatic effects. This formalism was recently developed into an ab initio density functional theory framework. Within this framework we here develop a perturbative approach to the electronic states in solid state materials. We derive exact-factorization-based perturbations of the Kohn-Sham states up to second order in the nuclear displacements. These non-adiabatic features in the calculated energy and wavefunction corrections are expressed in terms of readily available density functional perturbation theory components.

arXiv:2502.07439 (2025)

Materials Science (cond-mat.mtrl-sci)

Emergence of topological superconductivity in the presence of chiral magnetism in 2D CrInTe\(_3\)

New Submission | Superconductivity (cond-mat.supr-con) | 2025-02-12 20:00 EST

Arnob Mukherjee, Fengyi Zhou, Soheil Ershadrad, Tanay Nag, Duo Wang, Biplab Sanyal

We propose a general framework for designing a two-dimensional (2D) topological superconductor (TSC) using a magnet-superconductor hybrid system. This setup involves a monolayer of CrInTe\(_3\), which hosts noncoplanar magnetic textures, in proximity to a 2D \(s\)-wave superconducting layer. Serving as an alternative to \(p\)-wave superconductors, this configuration induces a topological superconducting phase and is a promising platform for realizing the 2D Kitaev model, which supports Majorana zero-energy modes through emergent \(p\)-wave symmetry superconducting pairing. Notably, the magnetic moments break time-reversal symmetry while the superconducting state preserves particle-hole symmetry, placing our system in the Altland-Zirnbauer class \(D\) and ensuring robust Majorana excitations. We first perform density functional theory-based simulations to study a monolayer of CrInTe\(_3\), from which essential magnetic characteristic parameters, such as Heisenberg exchange interaction and Dzyaloshinskii-Moriya interaction (DMI), are calculated using the state-of-the-art Liechtenstein-Katsnelson-Antropov-Gubanov (LKAG) approach. With a substantial DMI coupling exhibited in CrInTe\(_3\), large-scale Monte Carlo simulations reveal the stabilization of a noncoplanar spiral magnetic state as ground state. In this magnetic phase, we observe a transition from corner modes in the zero-energy local density of states (LDOS) to edge modes as the chemical potential (\(\mu\)) varies. Furthermore, under a finite magnetic field, the system enters a mixed magnetic state, characterized by isolated skyrmions and spiral domain walls, which lead to unique low-energy localization of electronic wave functions, rendering the system an insulator. Finally, we discuss potential experimental realizations of TSC in this magnet-superconductor interfacial system, using real-space probes such as scanning tunneling microscopy (STM).

arXiv:2502.07446 (2025)

Superconductivity (cond-mat.supr-con)

12 pages, 7 figures, 1 table

Enhancement of damping in a turbulent atomic Bose-Einstein condensate

New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-02-12 20:00 EST

Junghoon Lee, Jongmin Kim, Jongheum Jung, Yong-il Shin

We investigate the collective oscillations of atomic Bose-Einstein condensates (BECs) containing spin-superflow turbulence and observe an enhancement in damping due to the turbulence. As steady-state turbulence is maintained in a spin-1 BEC using a spin-driving technique, we measure the damping rate of the quadrupole oscillation of the BEC across a range of temperatures and show that it exceeds the thermal damping rate predicted by a Landau damping model for BECs without turbulence. To explain the additional damping, we introduce an effective viscosity \(\nu_\text{T}\), analogous to the turbulent viscosity in classical turbulence. Our measurements suggest that \(\nu_\text{T}\sim 0.05 \times \frac{h}{m}\), where \(h\) is Planck's constant and \(m\) is the atomic mass.

arXiv:2502.07449 (2025)

Quantum Gases (cond-mat.quant-gas)

12 pages, 6 figures

Effective description of Taylor dispersion in strongly corrugated channels

New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-02-12 20:00 EST

Arthur Alexandre, Thomas Guérin, David S. Dean

Taylor dispersion in periodic but highly corrugated channels is studied. Exact analytical expressions for the long-time diffusion constant and drift along the channel are derived to next-to-leading order in the limit of small channel period. Using these results we show how an effective model for Taylor dispersion in tortuous porous media can be framed in terms of dispersion in a uniform channel with absorption/desorption at its surface, an effective slip length for the flow at the surface and an effective, universal, diffusion constant on the surface. This work thus extends the concept of an effective slip-length for hydrodynamics flows to Taylor dispersion by those flows. The analytical results are confirmed by numerical calculations, and present a robust method to understand and upscale the transport properties of flows in porous media.

arXiv:2502.07464 (2025)

Statistical Mechanics (cond-mat.stat-mech), Fluid Dynamics (physics.flu-dyn)

21 pages, 3 figures

A multiscale Bayesian approach to quantification and denoising of energy-dispersive x-ray data

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Pau Torruella, Abderrahim Halimi, Ludovica Tovaglieri, Céline Lichtensteiger, Duncan T. L. Alexander, Cécile Hébert

Energy dispersive X-ray (EDX) spectrum imaging yields compositional information with a spatial resolution down to the atomic level. However, experimental limitations often produce extremely sparse and noisy EDX spectra. Under such conditions, every detected X-ray must be leveraged to obtain the maximum possible amount of information about the sample. To this end, we introduce a robust multiscale Bayesian approach that accounts for the Poisson statistics in the EDX data and leverages their underlying spatial correlations. This is combined with EDX spectral simulation (elemental contributions and Bremsstrahlung background) into a Bayesian estimation strategy. When tested using simulated datasets, the chemical maps obtained with this approach are more accurate and preserve a higher spatial resolution than those obtained by standard methods. These properties translate to experimental datasets, where the method enhances the atomic resolution chemical maps of a canonical tetragonal ferroelectric PbTiO3 sample, such that ferroelectric domains are mapped with unit-cell resolution.

arXiv:2502.07473 (2025)

Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Data Analysis, Statistics and Probability (physics.data-an)

Topological superconductivity in hourglass Dirac chain metals (Ti, Hf)IrGe

New Submission | Superconductivity (cond-mat.supr-con) | 2025-02-12 20:00 EST

Pavan Kumar Meena, Dibyendu Samanta, Sonika Jangid, Roshan Kumar Kushwaha, Rhea Stewart, Adrian D. Hillier, Sudeep Kumar Ghosh, Ravi Prakash Singh

Realizing topological superconductivity in stoichiometric materials is a key challenge in condensed matter physics. Here, we report the discovery of ternary germanide superconductors, \(M\)IrGe (\(M\) = Ti, Hf), as prime candidates for topological superconductivity, predicted to exhibit nonsymmorphic symmetry-protected hourglass Dirac chains. Using comprehensive thermodynamic and muon-spin rotation/relaxation (\(\mu\)SR) measurements, we establish these materials as conventional bulk type-II superconductors with transition temperatures of 2.24(5) K for TiIrGe and 5.64(4) K for HfIrGe, featuring a full gap and preserved time-reversal symmetry. First-principles calculations reveal striking topological features in \(M\)IrGe, including hourglass-shaped bulk dispersions and a Dirac chain- a ring of fourfold-degenerate Dirac points protected by nonsymmorphic symmetry. Each Dirac point corresponds to the neck of the hourglass dispersion, while the Dirac chain gives rise to drumhead-like surface states near the Fermi level. Additionally, nontrivial \(\mathbb{Z}_2\) topology leads to isolated Dirac surface states with helical spin textures that disperse across the Fermi level, forming an ideal platform for proximity-induced topological superconductivity. The coexistence of conventional bulk superconductivity, symmetry-protected hourglass topology, and helical spin-textured surface states establishes \(M\)IrGe as a rare and robust platform to realize topological superconductivity, opening new avenues for next-generation quantum technologies.

arXiv:2502.07475 (2025)

Superconductivity (cond-mat.supr-con)

10 pages, 3 figures

Robust zero modes in PbTe-Pb hybrid nanowires

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Shan Zhang, Wenyu Song, Zonglin Li, Zehao Yu, Ruidong Li, Yuhao Wang, Zeyu Yan, Jiaye Xu, Zhaoyu Wang, Yichun Gao, Shuai Yang, Lining Yang, Xiao Feng, Tiantian Wang, Yunyi Zang, Lin Li, Runan Shang, Qi-Kun Xue, Ke He, Hao Zhang

Majorana zero modes in tunneling conductance are expected to manifest as robust zero bias peaks (ZBPs). While ZBPs alone are not conclusive evidence of Majorana modes due to alternative explanations, robust ZBPs remain a crucial and necessary first-step indicator in the search for topological states. Here, we report the observation of robust ZBPs in PbTe-Pb hybrid nanowires. The peak height can reach \(2e^2/h\), though it does not yet form a quantized plateau. Importantly, these ZBPs can remain non-split over sizable ranges in both magnetic field and gate voltage scans, highlighting their robustness. We discuss possible interpretations based on Majorana zero modes as well as Andreev bound states.

arXiv:2502.07477 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

Predicting structure and swelling of microgels with different crosslinker concentrations combining machine-learning with numerical simulations

New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-02-12 20:00 EST

Susana Marín-Aguilar, Emanuela Zaccarelli

Microgels made of poly(N-isopropylacrylamide) are the prototype of soft, thermoresponsive particles widely used to study fundamental problems in condensed matter physics. However, their internal structure is far from homogeneous, and existing mean-field approaches, such as Flory-Rehner theory, provide only qualitative descriptions of their thermoresponsive behavior. Here, we combine machine learning and numerical simulations to accurately predict the concentration and spatial distribution of crosslinkers, the latter hitherto unknown experimentally, as well as the full swelling behavior of microgels, using only polymer density profiles. Our approach provides unprecedented insight into structural and thermodynamic properties of any standard microgel, including experimental ones.

arXiv:2502.07482 (2025)

Soft Condensed Matter (cond-mat.soft)

Effect of 3d Transition Metal Doping (Mn, Fe, Co, Ni) on the Electronic and Magnetic Properties of Pd Alloys at Low Impurity Concentrations: An Ab initio Study

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Irina I. Piyanzina, Zarina I. Minnegulova, Regina M. Burganova, Oleg V. Nedopekin, Igor V. Yanilkin, Vasiliy S. Stolyarov, Amir I. Gumarov

The nature of low-impurity ferromagnetism remains a challenging problem in the solid-state community. Despite initial experiments dating back to the mid-20th century, a comprehensive theoretical explanation and reliable ab initio evaluations have remained elusive. The present research aims to bridge this gap by refining first-principle calculations by elucidating the magnetic and electronic behavior of Pd1-xMx alloys (where M = Mn, Fe, Co, Ni). Our study includes calculations of magnetic properties throughout the range of impurity concentrations, from 1 to 100 atomic percent (at.%), where we estimate critical concentrations and perform a comparative analysis for the listed alloys. Furthermore, electronic structure was analyzed, including the calculations of atomic, spin, and orbital-resolved states density, and exploration of the spatial formation of magnetic clusters containing ferromagnetic impurities across all concentration ranges.

arXiv:2502.07485 (2025)

Materials Science (cond-mat.mtrl-sci)

From surface Fermi arcs to Fermi loops in the Dirac semimetal Cd3As2

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

An-Qi Wang, Tong-Yang Zhao, Chuan Li, Alexander Brinkman, Chun-Guang Chu, Zhi-Min Liao

Arc-like topological surface states, i.e., surface Fermi arcs, have long been recognized as the hallmark of Dirac semimetals. However, recent theories suggest that the surface Fermi arcs could evolve into closed Fermi loops, akin to surface states in topological insulators, while preserving the bulk Dirac semimetal phase. Here we experimentally reveal the evolution of Fermi arcs to Fermi loops in the surface-modified Dirac semimetal Cd3As2 nanoplate through gate voltage-dependent spin transport and quantum oscillation measurements. Surface modification, achieved by heavy metal atom deposition and water molecule adsorption, leads to an increase in the current-induced spin polarization at higher gate voltages, contrasting with the decrease observed in the pristine nanoplate. We also observe surface Shubnikov-de Haas oscillations with frequencies that scale linearly with gate voltage, aligning with a Fermi loop scenario. These findings indicate a transition from Fermi arcs to a closed Fermi loop in the surface-modified Cd3As2 nanoplate, consistent with the theoretically predicted fragile topological nature of Cd3As2. Our research offers profound insights into the transitions among these subtle topological states in Dirac semimetals, paving the way for manipulating topological surface states for high-performance spintronic devices.

arXiv:2502.07499 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

Two Channel Multi impurity Kondo model

New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-02-12 20:00 EST

A. M. Tsvelik, G. Kotliar

We show that the Ruderman-Kittel-Kasua-Yoisida interaction in two channel Kondo impurity systems is a relevant perturbation when the number of impurities N is greater than 3. We find a new critical point with anomalous dimensions 1/(N+1) for the spin operator and the Sommerfeld coefficient of the specific heat scales as \(\gamma \sim T^{- \frac{3}{N+1}} Inter-channel hybridization plays the role of the most relevant operator at this fixed point having anomalous dimensions (N-1)/(2N+2)\). The critical point universal properties are relevant to many strong correlation problems, such as impurity placed in a Majorana metal and the multichannel Kondo lattice model of heavy fermion materials. We discuss relevance of our results for cluster DMFT studies of quantum criticality.

arXiv:2502.07506 (2025)

Strongly Correlated Electrons (cond-mat.str-el)

The Role of 11B4C Interlayers in Enhancing Fe/Si Multilayer Performance for Polarized Neutron Mirrors

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Anton Zubayer, Fredrik Eriksson, Martin Falk, Marcus Lorentzon, Justinas Palisaitis, Christine Klauser, Gyula Nagy, Philipp M. Wolf, Eduardo Pitthan, Radek Holeňák, Daniel Primetzhofer, Gavin B.G. Stenning, Artur Glavic, Jochen Stahn, Samira Dorri, Per Eklund, Jens Birch, Naureen Ghafoor

This study investigates the effects of incorporating 11B4C interlayers into Fe/Si multilayers, with a focus on interface quality, reflectivity, polarization, and magnetic properties for polarized neutron optics. It is found that the introduction of 1 Å and 2 Å 11B4C interlayers significantly improves the interface sharpness, reducing interface width and preventing excessive Si diffusion into the Fe layers. X-ray reflectivity and polarized neutron reflectivity measurements show enhanced reflectivity and polarization, with a notable increase in polarization for 30 Å period multilayers. The inclusion of interlayers also helps prevent the formation of iron-silicides, improving both the magnetic properties and neutron optical performance. However, the impact of interlayers is less pronounced in thicker-period multilayers (100 Å), primarily due to the ratio between layer and interface widths. These results suggest that 11B4C interlayers offer a promising route for optimizing Fe/Si multilayer performance in polarized neutron mirrors.

arXiv:2502.07507 (2025)

Materials Science (cond-mat.mtrl-sci)

Diminished spin-flip reflectivity in stacked multilayers with varying period thicknesses of Fe/Si by incorporating 11B4C

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Anton Zubayer, Naureen Ghafoor, Anton Devishvili, Alexei Vorobiev, Artur Glavic, Jochen Stahn, Takayasu Hanashima, Jun Sugiyama, Vitor A. de Oliveira Lima, Jens Birch, Fredrik Eriksson

This study investigates the effects of 11B4C co-sputtering on the structural and optical properties of Fe/Si stacked multilayers, with a focus on neutron supermirror applications. X-ray and neutron reflectivity techniques reveal that 11B4C incorporation improves interface sharpness, reduces roughness, and enhances reflectivity for all multilayer periods. Neutron reflectivity measurements show reduced spin-flip intensities, while wafer-curvature measurements indicate a 50% reduction in internal stress, allowing for higher mechanical stability of the multilayers. These improvements are attributed to the amorphization of Fe layers, which also suppress the formation of structural and magnetic domains responsible for stress and spin-flip scattering. In contrast, the pure Fe/Si sample exhibits a persistent half-order Bragg peak, indicating residual antiferromagnetic coupling. The results demonstrate that 11B4C enhances neutron optics by reducing spin-flip effects, increasing reflectivity and polarization, and alleviating stress, enabling the use of polarizers at reduced external fields compared to pure Fe/Si multilayers. These findings establish 11B4C as a transformative material for advancing neutron supermirror technology, paving the way for more efficient, stable, and high-performance polarizers in next-generation neutron optics.

arXiv:2502.07512 (2025)

Materials Science (cond-mat.mtrl-sci)

Magnetic Domain Suppression in Fe/Si Multilayers with 11B4C Integration for Polarizing Neutron Optics

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Anton Zubayer, Artur Glavic, Naureen Ghafoor, Yuqing Ge, Yasmine Sassa, Martin Månsson, Andreas Suter, Thomas Prokscha, Zaher Salman, Wai-Tung Lee, Kristbjörg Anna Thórarinsdóttir, Arnaud Le Febvrier, Per Eklund, Jens Birch, Fridrik Magnus, Sean Langridge, Andrew Caruana, Christy Kinane, Fredrik Eriksson

This study explores the impact of boron carbide (B4C) addition on magnetic domains within Fe/Si multilayers through off-specular neutron scattering with polarization analysis. The incorporation of B4C induces amorphization in layers, disrupting magnetic domain structures. Analysis of the scattering patterns reveals that magnetic domains in pure Fe/Si multilayers exhibit no significant correlation between layers, resulting in a specific diffuse off-specular scattering signal, while the B4C incorporated Fe/Si multilayers revealed no diffuse off-specular scattering. We offer a qualitative interpretation of these scattering phenomena and accurately model the observed diffuse patterns using the distorted wave Born approximation. Low-energy {}+SR measurements further reveal that local magnetic fields in Fe/Si and Fe/Si + B4C multilayers are more easily manipulated by external fields in B4C-containing layers, with enhanced field uniformity in the muon length-scale. Our findings provide insights into the role of B4C in altering magnetic domain arrangements within Fe/Si multilayers, contributing to advances in the design of magnetic materials and neutron polarization coatings.

arXiv:2502.07515 (2025)

Materials Science (cond-mat.mtrl-sci)

Revealing Higher-Order Topological Bulk-boundary Correspondence in Bismuth Crystal with Spin-helical Hinge State Loop and Proximity Superconductivity

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

D.M.Zhao, Y. Zhong, T. Yuan, H.T. Wang, T.X. Jiang, Y. Qi, H.J. Xiang, X.G. Gong, D.L. Feng, T. Zhang

Topological materials are typically characterized by gapless boundary states originated from nontrivial bulk band topology, known as topological bulk-boundary correspondence. Recently, this fundamental concept has been generalized in higher-order topological insulators (HOTIs). E.g., a second-order three-dimensional (3D) TI hosts one-dimensional (1D) topological hinge states winding around the crystal. However, a complete verification of higher-order topology is still lacking as it requires probing all the crystal boundaries. Here we studied a promising candidate of second-order TI, bismuth (Bi), in the form of mesoscopic crystals grown on superconducting V3Si. Using low-temperature scanning tunneling microscopy, we directly observed dispersive 1D states on various hinges of the crystal. Upon introducing magnetic scatterers, new scattering channels emerged selectively on certain hinges, revealing their spin-helical nature. Combining first-principle calculation and global symmetry analysis, we find these hinge states are topological and formed a closed loop encircling the crystal. This provides direct evidence on the higher-order topology in Bi. Moreover, proximity superconductivity is observed in the topological hinge states, enabling HOTI as a promising platform for realizing topological superconductivity and Majorana quasiparticles.

arXiv:2502.07533 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)

28 pages,15 figures

Force-free kinetic inference of entropy production

New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-02-12 20:00 EST

Ivan Di Terlizzi

Estimating entropy production, which quantifies irreversibility and energy dissipation, remains a significant challenge despite its central role in nonequilibrium physics. We propose a novel method for estimating the mean entropy production rate \(\sigma\) that relies solely on position traces, bypassing the need for flux or microscopic force measurements. Starting from a recently introduced variance sum rule, we express \(\sigma\) in terms of measurable steady-state correlation functions which we link to previously studied kinetic quantities, known as traffic and inflow rate. Under realistic constraints of limited access to dynamical degrees of freedom, we derive efficient bounds on \(\sigma\) by leveraging the information contained in the system's traffic, enabling partial but meaningful estimates of \(\sigma\). We benchmark our results across several orders of magnitude in \(\sigma\) using two models: a linear stochastic system and a nonlinear model for spontaneous hair-bundle oscillations. Our approach offers a practical and versatile framework for investigating entropy production in nonequilibrium systems.

arXiv:2502.07540 (2025)

Statistical Mechanics (cond-mat.stat-mech)

Spontaneous Symmetry Breaking of Cavity Vacuum and Emergent Gyrotropic Effects in Embedded moiré Superlattices

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Zuzhang Lin, Hsun-Chi Chan, Wenqi Yang, Yixin Sha, Cong Xiao, Shuang Zhang, Wang Yao

In an electronic system, spontaneous symmetry breaking can arise from many-body interaction between electrons, leading to degenerate ground states distinguishable by emergent effects otherwise prohibited by the symmetry. Here we show that ultrastrong coupling of a mesoscopic electronic system to the vacuum of a cavity resonator can lead to another paradigm of spontaneous breaking of spatial symmetries in both systems. As a pertinent example, we consider the orbital gyrotropic effects in a moiré superlattice embedded in a THz split ring cavity resonator. Our mean-field and exact diagonalization calculations consistently demonstrate a spontaneous parity symmetry breaking in both the electronic ground state and the cavity vacuum, leading to two degenerate hybrid ground states distinguished by their opposite orbital gyrotropic Hall and magnetic effects. These sizable responses in the cavity-embedded moiré superlattice are highly tunable by both the cavity field polarization and interlayer bias on the moiré superlattice, providing an advanced platform for manipulating gyrotropic effects.

arXiv:2502.07570 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)

Coherent control of ac-driven quantum transport and minimal excitations in the fractional quantum Hall effect

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Imen Taktak, Ines Safi

We investigate the challenges of achieving minimal excitations in the fractional quantum Hall effect and addressing Hong-Ou-Mandel -type setups under ac drives when the Tomonaga-Luttinger liquid description is adopted. We apply the unifying non-equilibrium perturbative approach to weak backscattering through a quantum point contact in a two or three terminal geometry such as the "anyon collider". We show that the photoassisted noise is always higher than the photoassisted current, thus is super-Poissonian. This is an alternative theorem to Levitov's one, violated in the TLL model, thus questioning the expression "photoassisted". In the two-terminal geometry, we analyze carefully the validity domain of the perturbative approach and the possibility to achieve the quantum regime close to frequency locking, where singularities give access to the fractional charge. Then we show the persistence of equilibrium contributions to photoassisted noise that prevent access to zero-temperature and Poissonian limits under Lorentzian pulses. Furthermore, we demonstrate that prior works on similar setups, as well as "Leviton crystallization" where the zero-temperature limit is inappropriate, may be unreliable. Our findings are also applicable to Hall interferometers, coherent conductors, and Josephson or phase-slip junctions strongly coupled to an ohmic environment under an ac bias.

arXiv:2502.07622 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)

12 pages, 4 figures

The impact of hole \(g\)-factor anisotropy on spin-photon entanglement generation with InGaAs quantum dots

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

P. R. Ramesh, E. Annoni, N. Margaria, D. A. Fioretto, A. Pishchagin, M. Morassi, A. Lemaître, M. F. Doty, P. Senellart, L. Lanco, N. Belabas, S. C. Wein, O. Krebs

Self-assembled InGaAs/GaAs quantum dots (QDs) are of particular importance for the deterministic generation of spin-photon entanglement. One promising scheme relies on the Larmor precession of a spin in a transverse magnetic field, which is governed by the in-plane \(g\)-factors of the electron and valence band heavy-hole. We probe the origin of heavy-hole \(g\)-factor anisotropy with respect to the in-plane magnetic field direction and uncover how it impacts the entanglement generated between the spin and the photon polarization. First, using polarization-resolved photoluminescence measurements on a single QD, we determine that the impact of valence-band mixing dominates over effects due to a confinement-renormalized cubic Luttinger \(q\) parameter. From this, we construct a comprehensive hole \(g\)-tensor model. We then use this model to simulate the concurrence and fidelity of spin-photon entanglement generation with anisotropic hole \(g\)-factors, which can be tuned via magnetic field angle and excitation polarization. The results demonstrate that post-growth control of the hole \(g\)-factor can be used to improve spin-photon cluster state generation.

arXiv:2502.07627 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)

Classification of Gapped Domain Walls of Topological Orders in 2+1 dimensions: A Levin-Wen Model Realization

New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-02-12 20:00 EST

Yanyan Chen, Siyuan Wang, Yu Zhao, Yuting Hu, Yidun Wan

This paper introduces a novel systematic construction of gapped domain walls (GDWs) within the Levin-Wen (LW) model, advancing our understanding of topological phases. By gluing two LW models along their open sides in a compatible way, we achieve a complete GDW classification by subsets of bulk input data, encompassing \(e\)-\(m\) exchanging GDWs. A generalized bimodule structure is introduced to capture domain-wall excitations. Furthermore, we demonstrate that folding along any GDW yields a gapped boundary (GB) described by a Frobenius algebra of the input UFC for the folded model, thus bridging GDW and GB classifications within a unified framework.

arXiv:2502.07664 (2025)

Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph)

23+20 pages, 4+1 figures

Theory of Generalized Hertzian Hyperspheres

New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-02-12 20:00 EST

Ulf R. Pedersen

While hard-sphere models form the foundation of theoretical condensed matter physics, real systems often exhibit some degree of softness. We present a theoretical and numerical study of a class of nearly hard-sphere systems, generalized Hertzian hyperspheres, where particles interact via a finite-range repulsive potential that allows slight overlaps. Well-studied examples of this class include particles with harmonic repulsions, Hertzian spheres, and Hertzian disks. We derive closed-form expressions for thermodynamic properties, coexistence pressures, and scaling laws governing structure and dynamics. The theory predicts how quantities scale with temperature, density, spatial dimension, and potential softness. These theoretical predictions are tested through numerical simulations in dimensions ranging from one to eight.

arXiv:2502.07665 (2025)

Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)

15 pages, 14 figures

Tomographic Signatures of Interacting Majorana and Andreev States in Superconductor-Semiconductor Transmon Qubits

New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-02-12 20:00 EST

Daniel Dahan, Konstantin Yavilberg, Talya Shnaider, Elena Lupo, Malcolm R. Connolly, Eran Ginossar, Eytan Grosfeld

Semiconductor-based Josephson junctions embedded within a Cooper-pair-box can host complex many-body states, such as interacting Andreev states and potentially other quasi-particles of topological origin. Here, we study the insights that could be revealed from a tomographic reconstruction of the Cooper-pair charge distribution of the junction prepared in its ground state. We posit that interacting and topological states can be identified from distinct signatures within the probability distribution of the charge states. Furthermore, the comprehensive dataset provides direct access to information theory metrics elucidating the entanglement between the charge sector of the superconductor and the microscopic degrees of freedom in the junction. We demonstrate how these metrics serve to further classify differences between the types of excitations in the junction.

arXiv:2502.07684 (2025)

Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)

Revisiting Phase Transitions of Yttrium: Insights from Density Functional Theory

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

Paras Patel, Madhavi H. Dalsaniya, Saurav Patel, Dominik Kurzydłowski, Krzysztof J. Kurzydłowski, Prafulla K. Jha

Understanding the mechanism of structural phase transitions in rare-earth elements is a fundamental challenge in condensed matter physics, with significant implications for materials science applications. In this study, we present a systematic investigation on the phase transitions of yttrium under low-pressure conditions ($<\(30 GPa) focusing on the hcp, Sm-type, and dhcp phases. A comparative analysis of the generalized gradient approximation (GGA) and meta-GGA functionals reveals that the PBE-GGA functional significantly underestimates the phase transition pressures, whereas the r\)^2$SCAN functional provides accurate predictions of phase transition pressures which are in excellent agreement with experimental data. The results confirm that the phase transitions in yttrium are driven by vibrational instabilities, as evidenced by the emergence of soft acoustic modes in the phonon dispersion curves for the hcp and Sm-type phase. Elastic properties calculations further confirm mechanical softening at the phase boundaries, particularly in the hcp phase, suggesting a strong correlation between elastic instability and structural transitions. These findings suggest that the emergence of soft modes in the phonon dispersion curves might be a key factor driving the structural phase transition in the rare earth materials.

arXiv:2502.07686 (2025)

Materials Science (cond-mat.mtrl-sci)

Adsorption Behavior of Greenhouse Gases on Carbon Nanobelts: A Semi-Empirical Tight-Binding Approach for Environmental Application

New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-02-12 20:00 EST

C. Aguiar, I. Camps

This research investigates the adsorption characteristics of carbon nanobelts (CNB) and Mobius carbon nanobelts (MCNB) interacting with various greenhouse gases, including NH3, CO2, CO, H2S, CH4, CH3OH, NO2, NO, and COCl2. The study employs semi-empirical tight-binding calculations via xTB software, complemented by topological analysis using MULTIWFN software. Comparative analysis reveals MCNB's superior adsorption properties, particularly for specific gases. Notable adsorption energies for MCNB were measured at -1.595eV, -0.669eV, and -0.637eV for NO, COCl2, and NO2, respectively, significantly exceeding the corresponding CNB values of -0.636eV, -0.449eV, and -0.438eV. The investigation of desorption kinetics demonstrates rapid recovery times (sub-millisecond) for most gas-nanobelt interactions, with the notable exception of the MCNB+NO system, which exhibits persistent bonding. Topological analysis confirms chemisorption mechanisms for NO, COCl2, and NO2 on both nanobelt variants, characterized by complex hybridizations of covalent and non-covalent interactions. Molecular dynamics simulations conducted in both packed configurations and dry air mixtures demonstrate the nanobelts' effective gas-attracting properties, maintaining consistent capture performance across different environmental conditions. These findings establish carbon nanobelts, particularly the Mobius configuration, as promising candidates for greenhouse gas capture technologies, offering potential applications in environmental remediation and climate change mitigation strategies.

arXiv:2502.07690 (2025)

Materials Science (cond-mat.mtrl-sci)

Hydrodynamic stresses in a multi-species suspension of active Janus colloids

New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-02-12 20:00 EST

Gennaro Tucci, Giulia Pisegna, Ramin Golestanian, Suropriya Saha

A realistic description of active particles should include interactions with the medium, commonly a momentum-conserving simple fluid, in which they are suspended. In this work, we consider a multi-species suspension of self-diffusiophoretic Janus colloids interacting via chemical and hydrodynamic fields. Through a systematic coarse-graining of the microscopic dynamics, we calculate the multi-component contribution to the hydrodynamic stress tensor of the incompressible Stokesian fluid in which the particles are immersed. For a single species, we find that the strength of the stress produced by the gradients of the number density field is determined by the particles' self-propulsion and chemotactic alignment, and can be tuned to be either contractile or extensile. For a multi-species system, we unveil how different forms of activity modify the stress tensor, and how non-reciprocity in hydrodynamic interactions emerges in an active binary mixture.

arXiv:2502.07744 (2025)

Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)

12 pages, 3 figures