CMP Journal 2025-09-24
Statistics
Nature: 26
Physical Review Letters: 18
arXiv: 75
Nature
A tweezer array with 6100 highly coherent atomic qubits
Original Paper | Atomic and molecular physics | 2025-09-23 20:00 EDT
Hannah J. Manetsch, Gyohei Nomura, Elie Bataille, Xudong Lv, Kon H. Leung, Manuel Endres
Optical tweezer arrays 1,2 have transformed atomic and molecular physics, now forming the backbone for a range of leading experiments in quantum computing 3-8, simulation 1,9-12, and metrology 13-15. Typical experiments trap tens to hundreds of atomic qubits, and recently systems with around one thousand atoms were realized without defining qubits or demonstrating coherent control 16-18. However, scaling to thousands of atomic qubits with long coherence times, low-loss, and high-fidelity imaging is an outstanding challenge and critical for progress in quantum science, particularly towards quantum error correction 19,20. Here, we experimentally realize an array of optical tweezers trapping over 6,100 neutral atoms in around 12,000 sites, simultaneously surpassing state-of-the-art performance for several metrics that underpin the success of the platform. Specifically, while scaling to such a large number of atoms, we demonstrate a coherence time of 12.6(1) seconds, a record for hyperfine qubits in an optical tweezer array. We show room-temperature trapping lifetimes of ~ 23 minutes, enabling record-high imaging survival of 99.98952(1)% with an imaging fidelity of over 99.99%. We present a plan for zone-based quantum computing 5,21 and demonstrate necessary coherence-preserving qubit transport and pick-up/drop-off operations on large spatial scales, characterized through interleaved randomized benchmarking. Our results, along with recent developments 8,22-24, indicate that universal quantum computing and quantum error correction with thousands to tens of thousands of physical qubits could be a near-term prospect.
Atomic and molecular physics, Quantum information, Quantum simulation, Qubits
The geoeconomic turn in decarbonization
Review Paper | Climate-change mitigation | 2025-09-23 20:00 EDT
Jonas Meckling
The rise of green industrial policy is transforming efforts to decarbonize the global economy and mitigate climate change. The first three decades of climate policy centred on international cooperation on dividing up the costs of mitigation. In the new era of green industrial policy, geoeconomic competition for the benefits of decarbonization has emerged alongside international cooperation on emissions reductions. Governments invest in the manufacturing and deployment of clean technologies to advance economic development, energy security and emissions cuts. Geoeconomic competition has the potential to accelerate global decarbonization by facilitating greater technology deployment, speeding up technology cost declines and, thus, lowering the barriers to climate action. However, it also creates major pitfalls by facilitating the rise of trade protectionism, creating international conflict, and reproducing economic divides between richer and poorer, yet growing, countries. It is thus uncertain how the geoeconomic turn will impact global decarbonization. Meanwhile, policymakers are asking fundamental questions about how to design industrial policy, manage politics, develop institutions, and deal with the trade-offs between economic, climate and security goals. This Perspective demonstrates the recent geoeconomic turn in decarbonization, lays out its implications for policymaking, identifies global spillovers and addresses research needs.
Climate-change mitigation, Political economy of energy
Industry-compatible silicon spin-qubit unit cells exceeding 99% fidelity
Original Paper | Computational nanotechnology | 2025-09-23 20:00 EDT
Paul Steinacker, Nard Dumoulin Stuyck, Wee Han Lim, Tuomo Tanttu, MengKe Feng, Santiago Serrano, Andreas Nickl, Marco Candido, Jesus D. Cifuentes, Ensar Vahapoglu, Samuel K. Bartee, Fay E. Hudson, Kok Wai Chan, Stefan Kubicek, Julien Jussot, Yann Canvel, Sofie Beyne, Yosuke Shimura, Roger Loo, Clement Godfrin, Bart Raes, Sylvain Baudot, Danny Wan, Arne Laucht, Chih Hwan Yang, Andre Saraiva, Christopher C. Escott, Kristiaan De Greve, Andrew S. Dzurak
Among the many types of qubit presently being investigated for a future quantum computer, silicon spin qubits with millions of qubits on a single chip are uniquely positioned to enable quantum computing. However, it has not been clear whether the outstanding high-fidelity operations and long coherence times shown by silicon spin qubits fabricated in academic settings1,2,3,4,5,6,7,8 can be reliably reproduced when the qubits are manufactured in a semiconductor foundry9,10,11. Here we show precise qubit operation of silicon two-qubit devices made with standard semiconductor tooling in a 300-mm foundry environment. Of the key metrics, single- and two-qubit control fidelities exceed 99% for all four devices, and the state preparation and measurement fidelities reach up to 99.9%, as evidenced by gate set tomography. We report spin lifetime and coherence up to T1 = 9.5 s, ({T}{2}^{* }=40.6,{\rm{\mu }}{\rm{s}}) and ({T}{2}^{ {\rm{Hahn}}}=1.9,{\rm{ms}}). We determine that residual nuclear spin-carrying isotopes contribute substantially to operational errors, identifying further isotopic purification as a clear pathway to even higher performance.
Computational nanotechnology, Electrical and electronic engineering, Electronic devices, Quantum dots, Qubits
SPP1 is required for maintaining mesenchymal cell fate in pancreatic cancer
Original Paper | Extracellular signalling molecules | 2025-09-23 20:00 EDT
Huafu Li, Linxiang Lan, Hengxing Chen, May Zaw Thin, Hari Ps, Jessica K. Nelson, Ian M. Evans, E. Josue Ruiz, Rongjie Cheng, Li Tran, Mark Allen, Jian Ma, Tingzhuang Yi, Chunming Wang, Yulong He, Naomi Guppy, Anguraj Sadanandam, Shao-Zhen Lin, Changhua Zhang, Axel Behrens
Elucidating the complex network of communication between tumour cells is central to understanding cell fate decisions and progression of pancreatic ductal adenocarcinoma (PDAC)1,2. We previously showed that constant suppression of BMP activity by the BMP antagonist GREM1 secreted by mesenchymal PDAC cells is essential for maintaining the fate of epithelial PDAC cells3. Here we identify SPP1 (also known as osteopontin)4 as a key regulator of mesenchymal cell fate in pancreatic cancer. Proteomic analysis of plasma from patients with PDAC showed that SPP1 is substantially upregulated in late-stage disease. Inactivation of Spp1 led to a delay in tumorigenesis in mouse PDAC models and abolished metastasis formation. Spp1 was expressed in epithelial PDAC cells, and Spp1 inactivation resulted in a conversion of mesenchymal to epithelial PDAC cells. Mechanistically, SPP1 bound the CD61 receptor on mesenchymal PDAC cells to induce Bmp2 and Grem1 expression, and GREM1 inhibition of BMP signalling was required for Spp1 expression in epithelial cells, thereby forming an intercellular regulatory loop. Concomitant inactivation of Grem1 reverted the epithelial phenotype of Spp1 knockout to fully mesenchymal PDAC. Conversely, Grem1 heterozygosity combined with Spp1 knockout resulted in wild-type PDAC histology, a result that confirmed the direct antagonistic functions of these factors. Hence, mesenchymal and epithelial PDAC cell fates are determined by the reciprocal paracrine regulation of the soluble factors GREM1 and SPP1.
Extracellular signalling molecules, Tumour heterogeneity
Convergent evolution of diverse jaw joints in mammaliamorphs
Original Paper | Evolutionary developmental biology | 2025-09-23 20:00 EDT
Fangyuan Mao, Shan Jiang, Jun Liu, Jicheng Ren, Yong Ye, Yu Liu, Xin Shen, Tao Wang, Guofu Wang, Ping Wang, Juan Chen, Jin Meng
The evolution of a single-dentary-boned lower jaw and its secondary craniomandibular articulation between the dentary condyle and the squamosal glenoid has been regarded as a pivotal vertebrate innovation and defining mammalian trait1,2,3,4,5,6,7. Here we report two mammaliamorphs with novel shapes of secondary jaw joint, offering insight into the evolution of the mammalian jaw. The first, Polistodon8, a Middle Jurassic herbivorous tritylodontid with a relatively large body size and a lifestyle that is likely to have been fossorial, uniquely evolved a dentary-jugal articulation. The second, an Early Jurassic morganucodontan, exhibits a dentary-squamosal joint that lacks a bulbous condyle, supporting the hypothesis that the mammalian dentary condyle was formed by expansion of the lateral ridge of the dentary9. These diverse joints reflect repeated evolutionary experimentation in advanced cynodonts, in which secondary jaw joints arose independently7,10, and in which the load-bearing dentary-squamosal joint is a synapomorphy of mammaliaforms. Although body miniaturization might have driven this transformation11, our findings indicate that other factors were involved, such as jaw-muscle reorganization, feeding ecology and masticatory behaviour7,12,13,14,15,16,17. The ecomorphological diversity of these taxa suggest that phenotypic plasticity and environmentally induced morphological changes18,19,20 could have shaped jaw-joint evolution, emphasizing how ecological pressures and developmental flexibility guided the diversification of jaw structures in mammalian ancestors.
Evolutionary developmental biology, Palaeontology, Phylogenetics, Taxonomy
Ribonucleotide incorporation into mitochondrial DNA drives inflammation
Original Paper | Mitochondria | 2025-09-23 20:00 EDT
Amir Bahat, Dusanka Milenkovic, Eileen Cors, Mabel Barnett, Sadig Niftullayev, Athanasios Katsalifis, Marc Schwill, Petra Kirschner, Thomas MacVicar, Patrick Giavalisco, Louise Jenninger, Anders R. Clausen, Vincent Paupe, Julien Prudent, Nils-Göran Larsson, Manuel Rogg, Christoph Schell, Isabella Muylaert, Erik Lekholm, Hendrik Nolte, Maria Falkenberg, Thomas Langer
Metabolic dysregulation can lead to inflammatory responses1,2. Imbalanced nucleotide synthesis triggers the release of mitochondrial DNA (mtDNA) to the cytosol and an innate immune response through cGAS-STING signalling3. However, how nucleotide deficiency drives mtDNA-dependent inflammation has not been elucidated. Here we show that nucleotide imbalance leads to an increased misincorporation of ribonucleotides into mtDNA during age-dependent renal inflammation in a mouse model lacking the mitochondrial exonuclease MGME14, in various tissues of aged mice and in cells lacking the mitochondrial i-AAA protease YME1L. Similarly, reduced deoxyribonucleotide synthesis increases the ribonucleotide content of mtDNA in cell-cycle-arrested senescent cells. This leads to mtDNA release into the cytosol, cGAS-STING activation and the mtDNA-dependent senescence-associated secretory phenotype (SASP), which can be suppressed by exogenously added deoxyribonucleosides. Our results highlight the sensitivity of mtDNA to aberrant ribonucleotide incorporation and show that imbalanced nucleotide metabolism leads to age- and mtDNA-dependent inflammatory responses and SASP in senescence.
Mitochondria, Senescence, Stress signalling
Tailoring polymer electrolyte solvation for 600 Wh kg-1 lithium batteries
Original Paper | Chemistry | 2025-09-23 20:00 EDT
Xue-Yan Huang, Chen-Zi Zhao, Wei-Jin Kong, Nan Yao, Zong-Yao Shuang, Pan Xu, Shuo Sun, Yang Lu, Wen-Ze Huang, Jin-Liang Li, Liang Shen, Xiang Chen, Jia-Qi Huang, Lynden A. Archer, Qiang Zhang
Polymer electrolytes paired with lithium-rich manganese-based layered oxide (LRMO) cathodes and anode-free cell design are considered one of the most promising high-energy-density and high-safety systems1,2,3,4. However, the unstable anode morphological changes and the irreversible anionic reactions at the electrolyte-cathode interfaces induce oxygen escape and catalytic decomposition of polymer electrolytes, resulting in severe interfacial degradation and poor cycling stability. Here we design an in-built fluoropolyether-based polymer electrolyte composed of strongly solvating polyether and weakly solvating fluorohydrocarbon pendants, creating an anion-rich solvation structure and thus anion-derived fluorine-rich interfacial layers on the cathode and anode to resist interfacial issues. The LRMO cathode exhibits improved oxygen redox reversibility with substantially reduced oxygen-involving interfacial side reactions. This quasi-solid-state polymer electrolyte with 30 wt% trimethyl phosphate enables an LRMO cathode with a reversible high-areal-capacity cycling (>8 mAh cm-2) in pouch cells and long-term stability (>500 cycles at 25 °C) in coin cells, respectively. The pouch cells exhibit an energy density of 604 Wh kg-1 (1,027 Wh l-1) and excellent safety under a nail penetration at a fully charged condition. Our work, therefore, provides a promising direction for creating practical high-energy-density and high-safety lithium batteries.
Chemistry, Materials science
Diverging fish biodiversity trends in cold and warm rivers and streams
Original Paper | Biodiversity | 2025-09-23 20:00 EDT
Samantha L. Rumschlag, Brian Gallagher, Ryan Hill, Ralf B. Schäfer, Travis S. Schmidt, Taylor Woods, Darin Kopp, Michael Dumelle, Jason R. Rohr, Frederik De Laender, Joel Hoffman, Jonathan Behrens, Ryan Lepak, Devin K. Jones, Michael B. Mahon
Worldwide, freshwater systems contain more than 18,000 fish species1,2,3, which are critical to the functioning of these ecosystems4 and are vital cultural and economic resources to humans5,6,7; despite this value, fish biodiversity is at risk globally8,9. In the USA, leading threats to fish communities in rivers and streams include climate change and invasive fish introductions and game fish stocking by humans10,11,12,13,14. Here we harmonized US federal biomonitoring datasets with 389 species spanning 27 years (1993-2019) and 2,992 sites to analyse trends in fish biodiversity. In cold streams (past summer stream temperatures below 15.4 °C), fish abundance and richness declined by 53.4% and 32% over 27 years, respectively, and uniqueness increased. Periodic (large-bodied, late-maturing) fishes increased, and opportunists (small-bodied, short generation time, ‘r-selected’) decreased, possibly due to proliferation of native or introduced game fishes. In warm streams (stream temperatures greater than 23.8 °C), fish abundance and richness increased by 70.5% and 15.6% over 27 years, respectively, and communities homogenized. Small opportunistic fishes replaced large periodic fishes. Intermediate streams (stream temperatures 15.4-23.8 °C), representing the average stream, had minimal changes in fish biodiversity through time. Interactions between warming and introduced fish were associated with increased rates of degradation to local fish biodiversity. Given the magnitude of these changes in a relatively short time span, there is an urgent need to curb degradation of fish biodiversity caused by fish introductions and warming water temperatures.
Biodiversity, Climate-change impacts, Freshwater ecology
Volcanic crisis reveals coupled magma system at Santorini and Kolumbo
Original Paper | Geodynamics | 2025-09-23 20:00 EDT
Marius P. Isken, Jens Karstens, Paraskevi Nomikou, Michelle Maree Parks, Vincent Drouin, Eleonora Rivalta, Gareth J. Crutchley, Mahmud Haghshenas Haghighi, Emilie E. E. Hooft, Simone Cesca, Thomas R. Walter, Sebastian Hainzl, Joachim Saul, Dimitris Anastasiou, Kostas Raptakis, Nikolai M. Shapiro, Jannes Münchmeyer, Quentin Higueret, Jean Soubestre, Florent Brenguier, Rebeckah S. Hufstetler, Kaisa R. Autumn, Maria Tsakiri, Dietrich Lange, Heidrun Kopp, Morelia Urlaub, María Blanch Jover, Jonas Preine, Christian Hübscher, Mahdi Motagh, Daniel Müller, Torsten Dahm, Christian Berndt
Volcanic crises, driven by renewed magma inflow and migration, result in surface deformation and seismicity that can provide unique insights into the structure of volcanic systems and magmatic processes. Although the highly explosive volcanoes of Santorini and Kolumbo1,2 in the Greek Aegean Sea are just 7 km apart, their potentially coupled deep magmatic feeding systems are only poorly understood3,4. The 2025 volcano-tectonic crisis of Santorini simultaneously affected both volcanic centres, providing insights into a complex, multistorage feeder system. Here we integrate onshore and marine seismological data with geodetic measurements to reconstruct magma migration before and during the crisis. Gradual inflation in the Santorini caldera, beginning in mid-2024, preceded the January 2025 intrusion of a magma-filled dike sourced from a mid-crustal reservoir beneath Kolumbo, indicating a link between the two volcanoes. Joint inversion of ground and satellite-based deformation data indicates that approximately 0.31 km3 of magma intruded as an approximately 13-km-long dike, reactivating principal regional faults and arresting 3-5 km below the seafloor. The 2024-2025 resurgence of magmatic activity beneath both volcanic centres and their apparent coupling provides insights into the dynamic interplay of magma storage, transport and reservoir failure beneath neighbouring volcanoes.
Geodynamics, Geophysics, Natural hazards, Structural geology, Volcanology
Arousal as a universal embedding for spatiotemporal brain dynamics
Original Paper | Computational science | 2025-09-23 20:00 EDT
Ryan V. Raut, Zachary P. Rosenthal, Xiaodan Wang, Hanyang Miao, Zhanqi Zhang, Jin-Moo Lee, Marcus E. Raichle, Adam Q. Bauer, Steven L. Brunton, Bingni W. Brunton, J. Nathan Kutz
Neural activity in awake organisms shows widespread, spatiotemporally diverse correlations with behavioural and physiological measurements1,2,3,4. We propose that this covariation reflects in part the structured, nonlinear dynamics of an underlying arousal-related process that organizes brain-wide and body-wide physiology on the timescale of seconds. By framing this interpretation within dynamical systems theory, we arrive at a surprising prediction: a single, scalar measurement of arousal (for example, pupil diameter) should suffice to reconstruct the continuous evolution of multidimensional, spatiotemporal measurements of large-scale brain physiology. Here, to test this hypothesis, we perform multimodal cortex-wide optical imaging5 and behavioural monitoring in awake mice. We demonstrate that the seconds-scale spatiotemporal dynamics of neuronal calcium, metabolism and brain blood oxygen can be accurately and parsimoniously modelled from a low-dimensional, nonlinear manifold reconstructed from a time delay embedding6,7 of pupil diameter. Extending this framework to behavioural and electrophysiological measurements from the Allen Brain Observatory8, we demonstrate the ability to integrate diverse experimental data into a unified generative model via mappings from a shared arousal manifold. Our results support the hypothesis9 that spontaneous, spatially structured fluctuations in brain-wide physiology on timescales of seconds–widely interpreted to reflect regionally specific neural communication10,11–are in large part expressions of a low-dimensional, organism-wide dynamical system. In turn, reframing arousal itself as a latent dynamical system offers a new perspective on fluctuations in brain, body and behaviour observed across modalities, contexts and scales.
Computational science, Dynamical systems, Neurophysiology, Systems analysis, Wakefulness
Design of facilitated dissociation enables timing of cytokine signalling
Original Paper | Deformation dynamics | 2025-09-23 20:00 EDT
Adam J. Broerman, Christoph Pollmann, Yang Zhao, Mauriz A. Lichtenstein, Mark D. Jackson, Maxx H. Tessmer, Won Hee Ryu, Masato Ogishi, Mohamad H. Abedi, Danny D. Sahtoe, Aza Allen, Alex Kang, Joshmyn De La Cruz, Evans Brackenbrough, Banumathi Sankaran, Asim K. Bera, Daniel M. Zuckerman, Stefan Stoll, K. Christopher Garcia, Florian Praetorius, Jacob Piehler, David Baker
Protein design has focused on the design of ground states, ensuring that they are sufficiently low energy to be highly populated1. Designing the kinetics and dynamics of a system requires, in addition, the design of excited states that are traversed in transitions from one low-lying state to another2,3. This is a challenging task because such states must be sufficiently strained to be poorly populated, but not so strained that they are not populated at all, and because protein design methods have focused on generating near-ideal structures4,5,6,7. Here we describe a general approach for designing systems that use an induced-fit power stroke8 to generate a structurally frustrated9 and strained excited state, allosterically driving protein complex dissociation. X-ray crystallography, double electron-electron resonance spectroscopy and kinetic binding measurements show that incorporating excited states enables the design of effector-induced increases in dissociation rates as high as 5,700-fold. We highlight the power of this approach by designing rapid biosensors, kinetically controlled circuits and cytokine mimics that can be dissociated from their receptors within seconds, enabling dissection of the temporal dynamics of interleukin-2 signalling.
Deformation dynamics, Interleukins, Kinetics, Protein design, X-ray crystallography
Collective homeostasis of condensation-prone proteins via their mRNAs
Original Paper | RNA | 2025-09-23 20:00 EDT
Rupert Faraway, Neve Costello Heaven, Holly Digby, Klara Kuret Hodnik, Jure Rebselj, Oscar G. Wilkins, Anob M. Chakrabarti, Ira A. Iosub, Neža Vadnjal, Rhys Dore, Lea Knez, Stefan L. Ameres, Clemens Plaschka, Jernej Ule
The concentration of proteins containing intrinsically disordered regions must be tightly controlled to maintain cellular homeostasis1,2. However, mechanisms for collective control of these proteins, which tend to localize to membraneless condensates, are less understood than pathways mediated by membrane-bound organelles3,4. Here we report ‘interstasis’, a homeostatic mechanism in which increased concentration of proteins within RNA-protein condensates induces the sequestration of their own mRNAs. The selectivity of interstatic mRNA capture relies on the structure of the genetic code and conserved codon biases, which ensure that similar multivalent RNA regions encode similar low-complexity domains. For example, arginine-enriched mixed charge domains (R-MCDs) tend to be encoded by repetitive purine-rich sequences in mRNAs. Accumulation of proteins containing R-MCDs increases the cohesion of nuclear speckles, which induces selective capture of purine-rich multivalent mRNAs. The multivalent regions are bound by specific RNA-binding proteins, including TRA2 proteins, which relocalize to speckles upon interstasis to promote selective mRNA capture. CLK-mediated phosphorylation of TRA2 proteins counters their localization to speckles, thereby modulating interstasis. Thus, the condensation properties of nuclear speckles act as a sensor for interstasis, a collective negative-feedback loop that co-regulates mRNAs of highly dosage-sensitive genes, which primarily encode nuclear condensation-prone proteins.
RNA, RNA transport, Nuclear speckles
Robot-assisted mapping of chemical reaction hyperspaces and networks
Original Paper | Automation | 2025-09-23 20:00 EDT
Yankai Jia, Rafał Frydrych, Yaroslav I. Sobolev, Wai-Shing Wong, Bibek Prajapati, Daniel Matuszczyk, Yasemin Bilgi, Louis Gadina, Juan Carlos Ahumada, Galymzhan Moldagulov, Namhun Kim, Eric S. Larsen, Maxence Deschamps, Yanqiu Jiang, Bartosz A. Grzybowski
Despite decades of investigation, it remains unclear (and hard to predict1,2,3,4) how the outcomes of chemical reactions change over multidimensional ‘hyperspaces’ defined by reaction conditions5. Whereas human chemists can explore only a limited subset of these manifolds, automated platforms6,7,8,9,10,11,12 can generate thousands of reactions in parallel. Yet, purification and yield quantification remain bottlenecks, constrained by time-consuming and resource-intensive analytical techniques. As a result, our understanding of reaction hyperspaces remains fragmentary7,9,13,14,15,16. Are yield distributions smooth or corrugated? Do they conceal mechanistically new reactions? Can major products vary across different regions? Here, to address these questions, we developed a low-cost robotic platform using primarily optical detection to quantify yields of products and by-products at unprecedented throughput and minimal cost per condition. Scanning hyperspaces across thousands of conditions, we find and prove mathematically that, for continuous variables (concentrations, temperatures), individual yield distributions are generally slow-varying. At the same time, we uncover hyperspace regions of unexpected reactivity as well as switchovers between major products. Moreover, by systematically surveying substrate proportions, we reconstruct underlying reaction networks and expose hidden intermediates and products–even in reactions studied for well over a century. This hyperspace-scanning approach provides a versatile and scalable framework for reaction optimization and discovery. Crucially, it can help identify conditions under which complex mixtures can be driven cleanly towards different major products, thereby expanding synthetic diversity while reducing chemical input requirements.
Automation, Cheminformatics
Proximal cooperative aerial manipulation with vertically stacked drones
Original Paper | Aerospace engineering | 2025-09-23 20:00 EDT
Huazi Cao, Jiahao Shen, Yin Zhang, Zheng Fu, Cunjia Liu, Sihao Sun, Shiyu Zhao
Enabling vertical-stack proximal cooperation between multirotor flying robots can facilitate the execution of complex aerial manipulation tasks. However, vertical-stack proximal flight is commonly regarded as a dangerous condition that should be avoided because of persistent and intense downwash interference generated between flying robots1,2. Here we propose a cooperative aerial manipulation system, called FlyingToolbox, that can work stably with sub-centimetre-level docking accuracy under vertical-stack flight conditions. The system consists of a toolbox micro-aerial vehicle (MAV) and a manipulator MAV. The robotic arm of the manipulator MAV can autonomously dock with a tool carried by the toolbox MAV, in which the docking accuracy reaches 0.80 ± 0.33 cm in the presence of downwash airflow of up to 13.18 m s-1. By enabling midair tool exchange in proximity, FlyingToolbox resolves the paradox between flight proximity and manipulation accuracy, suggesting a new model for heterogeneous and interactive flying robot cooperation in diverse applications3,4,5.
Aerospace engineering, Electrical and electronic engineering
Isothermal solidification for high-entropy alloy synthesis
Original Paper | Metals and alloys | 2025-09-23 20:00 EDT
Qiubo Zhang, Max C. Gallant, Yi Chen, Zhigang Song, Yang Liu, Qi Zheng, Linfeng Chen, Karen. C. Bustillo, Yu Huang, Kristin A. Persson, Haimei Zheng
Kinetically trapping the high-temperature states through rapid cooling solidification is widely used for the synthesis of high-entropy alloys (HEAs), especially those with intrinsically immiscible elemental combinations1,2,3,4. However, strategies need to be developed to overcome the fundamental limitations of rapid cooling solidification in controlling the crystallinity, structure and morphology of HEAs. Here we introduce an isothermal solidification strategy for the synthesis of HEAs by rapidly altering the metal alloy composition through liquid-liquid interface reactions at low temperatures, for example, from 25 °C to 80 °C. We use gallium (Ga)-based metal as the sacrificial reagent and mixing medium. By directing the reactions to the interfaces between the Ga-based liquid metal and an aqueous metal ion solution, the foreign metal ions can be reduced at the interfaces and incorporated into the liquid metal quickly. HEAs with various crystallinity (single crystal, mesocrystal, polycrystal and amorphous), morphology (zero, two and three dimensions) and compositions can be achieved through the isothermal solidification. Ga can be completely consumed, resulting in Ga-free HEAs. If desired, Ga can be one of the metal elements in the final products. In situ liquid phase transmission electron microscopy (TEM) studies and theoretical analysis show the isothermal solidification mechanisms. Our direct observations show the enhanced mixing of liquid metal elements and the solidification process with fluctuating nucleation dynamics. The isothermal solidification marks a powerful strategy for HEA synthesis through an unexplored pathway of kinetically trapping the high-entropy states.
Metals and alloys, Synthesis and processing, Transmission electron microscopy
Holliday junction-ZMM protein feedback enables meiotic crossover assurance
Original Paper | Chromosomes | 2025-09-23 20:00 EDT
Adrian Henggeler, Lucija Orlić, Daniel Velikov, Joao Matos
Holliday junctions (HJs) are branched four-way DNA structures that link recombining chromosomes during double-strand break repair1. Despite posing a risk to chromosome segregation, HJs accumulate during meiotic prophase I as intermediates in the process of crossing-over2,3. Whether HJs have additional regulatory functions remains unclear. Here we establish an experimental system in budding yeast that enables conditional nucleolytic resolution of HJs after the establishment of meiotic chromosome synapsis. We find that HJ resolution triggers complete disassembly of the synaptonemal complex without disrupting the axis-loop organization of chromosomes. Mechanistically, HJs mediate the continued association of ZMM proteins with recombination nodules that form at the axes interface of homologous chromosome pairs. ZMM proteins, in turn, promote polymerization of the synaptonemal complex while simultaneously protecting HJs from processing by non-crossover pathways. Thus, reciprocal feedback between ZMMs, which stabilize HJs, and HJs, which retain ZMM proteins at future crossover sites, maintains chromosome synapsis until HJ-resolving enzymes are activated during exit from prophase I. Notably, by polymerizing and maintaining the synaptonemal complex structure, the HJ-ZMM interplay suppresses de novo double-strand break formation and recombination reinitiation. In doing so, this interplay suppresses the DNA damage response, enabling meiotic progression without unrepaired breaks and supporting crossover assurance.
Chromosomes, Genetic variation, Meiosis
Systematic discovery of CRISPR-boosted CAR T cell immunotherapies
Original Paper | Cancer | 2025-09-23 20:00 EDT
Paul Datlinger, Eugenia V. Pankevich, Cosmas D. Arnold, Nicole Pranckevicius, Jenny Lin, Daria Romanovskaia, Moritz Schaefer, Francesco Piras, Anne-Christine Orts, Amelie Nemc, Paulina N. Biesaga, Michelle Chan, Teresa Neuwirth, Artem V. Artemov, Wentao Li, Sabrina Ladstätter, Thomas Krausgruber, Christoph Bock
Chimeric antigen receptor (CAR) T cell therapy has shown remarkable success in treating blood cancers, but CAR T cell dysfunction remains a common cause of treatment failure1. Here we present CELLFIE, a CRISPR screening platform for enhancing CAR T cells across multiple clinical objectives. We performed genome-wide screens in human primary CAR T cells, with readouts capturing key aspects of T cell biology, including proliferation, target cell recognition, activation, apoptosis and fratricide, and exhaustion. Screening hits were prioritized using a new in vivo CROP-seq2 method in a xenograft model of human leukaemia, establishing several gene knockouts that boost CAR T cell efficacy. Most notably, we discovered that RHOG knockout is a potent and unexpected CAR T cell enhancer, both individually and together with FAS knockout, which was validated across multiple in vivo models, CAR designs and sample donors, and in patient-derived cells. Demonstrating the versatility of the CELLFIE platform, we also conducted combinatorial CRISPR screens to identify synergistic gene pairs and saturation base-editing screens to characterize RHOG variants. In summary, we discovered, validated and biologically characterized CRISPR-boosted CAR T cells that outperform standard CAR T cells in widely used benchmarks, establishing a foundational resource for optimizing cell-based immunotherapies.
Cancer, Functional genomics, Gene therapy, Immunotherapy, T cells
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Original Paper | Cancer metabolism | 2025-09-23 20:00 EDT
Sarah Cherkaoui, Christina S. Turn, Yuan Yuan, Wenyun Lu, Lifeng Yang, Matthew J. McBride, Caroline Eigenmann, George E. Allen, Olesya O. Panasenko, Lu Zhang, Annette Vu, Kangning Liu, Yimei Li, Om H. Gandhi, Lea F. Surrey, Sandra D. Kienast, Sebastian A. Leidel, Michael Wierer, Eileen White, Joshua D. Rabinowitz, Michael D. Hogarty, Raphael J. Morscher
Neuroblastoma is a highly lethal childhood tumour derived from differentiation-arrested neural crest cells1,2. Like all cancers, its growth is fuelled by metabolites obtained from either circulation or local biosynthesis3,4. Neuroblastomas depend on local polyamine biosynthesis, and the inhibitor difluoromethylornithine has shown clinical activity5. Here we show that such inhibition can be augmented by dietary restriction of upstream amino acid substrates, leading to disruption of oncogenic protein translation, tumour differentiation and profound survival gains in the Th-MYCN mouse model. Specifically, an arginine- and proline-free diet decreases the amount of the polyamine precursor ornithine and enhances tumour polyamine depletion by difluoromethylornithine. This polyamine depletion causes ribosome stalling, unexpectedly specifically at codons with adenosine in the third position. Such codons are selectively enriched in cell cycle genes and low in neuronal differentiation genes. Thus, impaired translation of these codons, induced by combined dietary and pharmacological intervention, favours a pro-differentiation proteome. These results suggest that the genes of specific cellular programmes have evolved hallmark codon usage preferences that enable coherent translational rewiring in response to metabolic stresses, and that this process can be targeted to activate differentiation of paediatric cancers.
Cancer metabolism, Cell growth, Paediatric research
LRP8 is a receptor for tick-borne encephalitis virus
Original Paper | Viral pathogenesis | 2025-09-23 20:00 EDT
Eva Mittler, Alexandra L. Tse, Pham-Tue-Hung Tran, Catalina Florez, Javier Janer, Renata Varnaite, Ezgi Kasikci, Vasantha Kumar MV, Michaela Loomis, Wanda Christ, Erik Cazares, Russell R. Bakken, Caroline K. Martin, Xiankun Zeng, Jo Lynne Raymond, Mansoureh Shahsavani, Sara Khanal, Eric R. Wilkinson, Rischa Maya Oktavia, Megan M. Slough, Denise Haslwanter, Julianna Han, Jacob Berrigan, Ebba Rosendal, Margaret Kielian, Balaji Manicassamy, Anna K. Överby, Anna Falk, Giovanna Barba-Spaeth, Felix A. Rey, Jonas Klingström, Evripidis Gavathiotis, Andrew S. Herbert, Kartik Chandran, Sara Gredmark-Russ
Tick-borne encephalitis virus (TBEV) causes tick-borne encephalitis (TBE), a severe and sometimes life-threatening disease characterized by viral invasion of the central nervous system with symptoms of neuroinflammation1,2. As with other orthoflaviviruses–enveloped, arthropod-borne RNA viruses–host factors required for TBEV entry remain poorly defined. Here we used a genome-scale CRISPR-Cas9-based screen to identify LRP8, an apolipoprotein E and reelin receptor with high expression in the brain, as a TBEV receptor. LRP8 downregulation reduced TBEV infection in human cells, and its overexpression enhanced infection. LRP8 bound directly to the TBEV E glycoprotein and mediated viral attachment and internalization into cells. An LRP8-based soluble decoy blocked infection of human cell lines and neuronal cells and protected mice from lethal TBEV challenge. LRP8’s role as a TBEV receptor has implications for TBEV neuropathogenesis and the development of antiviral countermeasures.
Viral pathogenesis, Virus-host interactions
A haplotype-based evolutionary history of barley domestication
Original Paper | Genomics | 2025-09-23 20:00 EDT
Yu Guo, Murukarthick Jayakodi, Axel Himmelbach, Erez Ben-Yosef, Uri Davidovich, Michal David, Anat Hartmann-Shenkman, Mordechai Kislev, Tzion Fahima, Verena J. Schuenemann, Ella Reiter, Johannes Krause, Brian J. Steffenson, Nils Stein, Ehud Weiss, Martin Mascher
Barley is one of the oldest cultivated crops, with a complex evolutionary and domestication history1. Previous studies have rejected the idea of a single origin and instead support a model of mosaic genomic ancestry2,3. With increasingly comprehensive genome data, we now ask where the haplotypes – the building blocks of this mosaic – originate, and whether all domesticated barleys share the same wild progenitors or whether certain wild populations contribute more heavily to specific lineages. To address these questions, we apply a haplotype-based approach to investigate the genetic diversity and population structure of wild and domesticated barley. We analyse whole-genome sequences from 682 genebank accessions and 23 archaeological specimens, tracing the spatiotemporal origins of haplotypes and identifying wild contributors during domestication and later gene flow events. Ancient DNA supports our genome-wide findings from modern samples. Our results suggest that a founding domesticated population emerged in the Fertile Crescent during a prolonged period of pre-domestication cultivation. A key practical insight is that the high haplotype differentiation among barley populations – arising independently, or layered on top, of selection – poses challenges for mapping adaptive loci.
Genomics, Plant evolution
The formation and propagation of human Robertsonian chromosomes
Original Paper | Cytogenetics | 2025-09-23 20:00 EDT
Leonardo Gomes de Lima, Andrea Guarracino, Sergey Koren, Tamara Potapova, Sean McKinney, Arang Rhie, Steven J. Solar, Chris Seidel, Brandon L. Fagen, Brian P. Walenz, Gerard G. Bouffard, Shelise Y. Brooks, Michael Peterson, Kate Hall, Juyun Crawford, Alice C. Young, Brandon D. Pickett, Erik Garrison, Adam M. Phillippy, Jennifer L. Gerton
Robertsonian chromosomes are a type of variant chromosome that is commonly found in nature. Present in 1 in 800 humans, these chromosomes can underlie infertility, trisomies and increased cancer incidence1,2,3,4,5. They have been recognized cytogenetically for more than a century6, yet their origins have remained unknown. Here we describe complete assemblies of three human Robertsonian chromosomes. We identified a common breakpoint in SST1, a macrosatellite DNA located on chromosomes 13, 14 and 21, which commonly undergo Robertsonian translocation. SST1 is contained within a larger shared homology domain7 that is inverted on chromosome 14, which enables a meiotic crossover event that fuses the long arms of two chromosomes. Robertsonian chromosomes have two centromeric DNA arrays and have lost all ribosomal DNA. In two cases, we find that only one of the two centromeric arrays is active. In the third case, both arrays can be active but owing to their proximity, they are often encompassed by a single outer kinetochore. Thus a combination of array proximity and epigenetic changes in centromeres facilitates the stable propagation of Robertsonian chromosomes. Investigation of the assembled genomes of chimpanzee and bonobo highlights that the inversion on chromosome 14 is unique to the human genome. Resolving the structural and epigenetic features of human Robertsonian chromosomes at a molecular level provides a foundation for a broader understanding of the molecular mechanisms of structural variation and chromosome evolution.
Cytogenetics, Evolutionary genetics, Genome informatics, Medical genetics
Protecting double Holliday junctions ensures crossing over during meiosis
Original Paper | Cohesion | 2025-09-23 20:00 EDT
Shangming Tang, Sara Hariri, Regina Bohn, John E. McCarthy, Jennifer Koo, Mohammad Pourhosseinzadeh, Emerald Nguyen, Natalie Liu, Christopher Ma, Hanyu Lu, Monica Lee, Neil Hunter
Chromosomal linkages formed through crossover recombination are essential for the accurate segregation of homologous chromosomes during meiosis1. The DNA events of recombination are linked to structural components of meiotic chromosomes2. Imperatively, the biased resolution of double Holliday junction (dHJ) intermediates into crossovers3,4 occurs within the synaptonemal complex (SC), the meiosis-specific structure that mediates end-to-end synapsis of homologues during the pachytene stage5,6. However, the role of the SC in crossover-specific dHJ resolution remains unclear. Here we show that key SC components function through dependent and interdependent relationships to protect dHJs from aberrant dissolution into non-crossover products. Conditional ablation experiments reveal that cohesin, the core of SC lateral elements, is required to maintain both synapsis and dHJ-associated crossover recombination complexes (CRCs) during pachytene. The SC central region transverse-filament protein is also required to maintain CRCs. Reciprocally, the stability of the SC central region requires the continuous presence of CRCs effectively coupling synapsis to dHJ formation and desynapsis to resolution. However, dHJ protection and CRC maintenance can occur without end-to-end homologue synapsis mediated by the central element of the SC central region. We conclude that local ensembles of SC components are sufficient to enable crossover-specific dHJ resolution to ensure the linkage and segregation of homologous chromosomes.
Cohesion, Development, Genomic instability, Meiosis
In vivo CRISPR screens identify modifiers of CAR T cell function in myeloma
Original Paper | Bone cancer | 2025-09-23 20:00 EDT
Nelson H. Knudsen, Giulia Escobar, Felix Korell, Tamina Kienka, Celeste Nobrega, Seth Anderson, Andrew Y. Cheng, Maria Zschummel, Alexander Armstrong, Amanda Bouffard, Michael C. Kann, Sadie Goncalves, Hans W. Pope, Mitra Pezeshki, Alexander Rojas, Juliette S. M. T. Suermondt, Merle Phillips, Trisha R. Berger, Sangwoo Park, Diego Salas-Benito, Elijah P. Darnell, Filippo Birocchi, Mark B. Leick, Rebecca C. Larson, John G. Doench, Debattama Sen, Kathleen B. Yates, Robert T. Manguso, Marcela V. Maus
Chimeric antigen receptor (CAR) T cells are highly effective in haematological malignancies1. However, progressive loss of CAR T cells contributes to relapse in many patients2,3,4. Here we performed in vivo loss-of-function CRISPR screens in CAR T cells targeting B cell maturation antigen to investigate genes that influence CAR T cell persistence and function in a human multiple myeloma model. We tracked the expansion and persistence of CRISPR library-edited T cells in vitro and at early and late time points in vivo to track the performance of gene-modified CAR T cells from manufacturing to survival in tumours. The screens revealed context-specific regulators of CAR T cell expansion and persistence. Ablation of RASA2 and SOCS1 enhanced T cell expansion in vitro, whereas loss of PTPN2, ZC3H12A and RC3H1 conferred early growth advantages to CAR T cells in vivo. Notably, we identified cyclin-dependent kinase inhibitor 1B (encoded by CDKN1B), a cell cycle regulator, as the most important factor limiting CAR T cell fitness at late time points in vivo. CDKN1B ablation increased CAR T cell proliferation and effector function, significantly enhancing tumour clearance and overall survival. Our findings reveal differing effects of gene perturbation on CAR T cells over time and in different environments, highlight CDKN1B as a promising target to generate highly effective CAR T cells for multiple myeloma and underscore the potential of in vivo screening for identifying genes to enhance CAR T cell efficacy.
Bone cancer, Immunotherapy, Preclinical research, Translational immunology
Electrostatic-repulsion-based transfer of van der Waals materials
Original Paper | Synthesis and processing | 2025-09-23 20:00 EDT
Xudong Zheng, Jiangtao Wang, Jianfeng Jiang, Tianyi Zhang, Jiadi Zhu, Tong Dang, Peng Wu, Ang-Yu Lu, Ding-Rui Chen, Tilo H. Yang, Xinyuan Zhang, Kenan Zhang, Kyung Yeol Ma, Zhien Wang, Aijia Yao, Haomin Liu, Yi Wan, Ya-Ping Hsieh, Vladimir Bulović, Tomás Palacios, Jing Kong
Van der Waals (vdW) materials offer unique opportunities for 3D integration1,2 of planar circuits towards higher-density transistors and energy-efficient computation3,4,5,6,7. Owing to the high thermal budget and special substrate requirement for the synthesis of high-quality vdW materials8,9,10, an advanced transfer technique is required that can simultaneously meet a broad range of industrial requirements, including high intactness, cleanliness and speed, large scale, low cost and versatility. However, previous efforts based on either etching or etching-free mechanisms typically only improve one or two of the aforementioned aspects11,12,13 and a comprehensive and systematic solution remains lacking. Here we demonstrate an electrostatic-repulsion-enabled advanced transfer technique that is etching free, high yield, fast, wafer scale, low cost and widely applicable, using ammonia solution compatible with the complementary metal-oxide-semiconductor (CMOS) industry. The high material intactness and interface cleanliness enable superior device performances in 2D field-effect transistors with 100% yield, near-zero hysteresis (7 mV) and near-ideal subthreshold swing (65.9 mV dec-1). The combination with bismuth contact further enables an ultrahigh on-current of 1.3 mA μm-1 under 1 V bias. This advanced transfer approach offers a facile and manufacturing-viable solution for vdW-materials-based electronics, paving the way for advanced 3D integration in the future.
Synthesis and processing, Two-dimensional materials
The Biodiversity Cell Atlas: mapping the tree of life at cellular resolution
Review Paper | Cell biology | 2025-09-23 20:00 EDT
Arnau Sebé-Pedrós, Amos Tanay, Mara K. N. Lawniczak, Detlev Arendt, Stein Aerts, John Archibald, Maria Ina Arnone, Mark Blaxter, Phillip Cleves, Susana M. Coelho, Mafalda Dias, Casey Dunn, Anamaria Elek, Jonathan Frazer, Toni Gabaldón, Jesse Gillis, Xavier Grau-Bové, Roderic Guigó, Oliver Hobert, Jaime Huerta-Cepas, Manuel Irimia, Allon Klein, Harris Lewin, Christopher J. Lowe, Heather Marlow, Jacob M. Musser, László G. Nagy, Sebastián R. Najle, Lior Pachter, Sadye Paez, Irene Papatheodorou, Michael J. Passalacqua, Nikolaus Rajewsky, Seung Y. Rhee, Thomas A. Richards, Tatjana Sauka-Spengler, Lauren M. Saunders, Eve Seuntjens, Jordi Solana, Yuyao Song, Ulrich Technau, Bo Wang
Cell types are fundamental functional units that can be traced across the tree of life. Rapid advances in single-cell technologies, coupled with the phylogenetic expansion in genome sequencing, present opportunities for the molecular characterization of cells across a broad range of organisms. Despite these developments, our understanding of eukaryotic cell diversity remains limited and we are far from decoding this diversity from genome sequences. Here we introduce the Biodiversity Cell Atlas initiative, which aims to create comprehensive single-cell molecular atlases across the eukaryotic tree of life. This community effort will be phylogenetically informed, rely on high-quality genomes and use shared standards to facilitate comparisons across species. The Biodiversity Cell Atlas aspires to deepen our understanding of the evolution and diversity of life at the cellular level, encompassing gene regulatory programs, differentiation trajectories, cell-type-specific molecular profiles and inter-organismal interactions.
Cell biology, Computational biology and bioinformatics, Evolutionary biology, Functional genomics, Phylogenetics
Low-overhead transversal fault tolerance for universal quantum computation
Original Paper | Computer science | 2025-09-23 20:00 EDT
Hengyun Zhou, Chen Zhao, Madelyn Cain, Dolev Bluvstein, Nishad Maskara, Casey Duckering, Hong-Ye Hu, Sheng-Tao Wang, Aleksander Kubica, Mikhail D. Lukin
Fast, reliable logical operations are essential for realizing useful quantum computers1,2,3. By redundantly encoding logical qubits into many physical qubits and using syndrome measurements to detect and correct errors, we can achieve low logical error rates. However, for many practical quantum error correction codes such as the surface code, owing to syndrome measurement errors, standard constructions require multiple extraction rounds–of the order of the code distance d–for fault-tolerant computation, particularly considering fault-tolerant state preparation4,5,6,7,8,9,10,11,12. Here we show that logical operations can be performed fault-tolerantly with only a constant number of extraction rounds for a broad class of quantum error correction codes, including the surface code with magic state inputs and feedforward, to achieve ‘transversal algorithmic fault tolerance’. Through the combination of transversal operations7 and new strategies for correlated decoding13, despite only having access to partial syndrome information, we prove that the deviation from the ideal logical measurement distribution can be made exponentially small in the distance, even if the instantaneous quantum state cannot be made close to a logical codeword because of measurement errors. We supplement this proof with circuit-level simulations in a range of relevant settings, demonstrating the fault tolerance and competitive performance of our approach. Our work sheds new light on the theory of quantum fault tolerance and has the potential to reduce the space-time cost of practical fault-tolerant quantum computation by over an order of magnitude.
Computer science, Quantum information, Quantum mechanics
Physical Review Letters
Optical Lattice Quantum Simulator of Dynamics beyond Born-Oppenheimer
Article | Atomic, Molecular, and Optical Physics | 2025-09-24 06:00 EDT
Javier Argüello-Luengo, Alejandro González-Tudela, and J. Ignacio Cirac
Here, we propose a platform based on ultracold fermionic molecules trapped in optical lattices to simulate nonadiabatic effects, as they appear in certain molecular dynamical problems. The idea consists of a judicious choice of two rotational states as the simulated electronic or nuclear degrees of …
Phys. Rev. Lett. 135, 133402 (2025)
Atomic, Molecular, and Optical Physics
Universal Kerr-Thermal Dynamics of Self-Injection-Locked Microresonator Dark Pulses
Article | Atomic, Molecular, and Optical Physics | 2025-09-24 06:00 EDT
Shichang Li, Kunpeng Yu, Dmitry A. Chermoshentsev, Wei Sun, Jinbao Long, Xiaoying Yan, Chen Shen, Artem E. Shitikov, Nikita Yu. Dmitriev, Igor A. Bilenko, and Junqiu Liu
Microcombs, formed in optical microresonators driven by continuous-wave lasers, are miniaturized optical frequency combs. Leveraging integrated photonics and laser self-injection locking, compact microcombs can be constructed via hybrid integration of a semiconductor laser with a chip-based microres…
Phys. Rev. Lett. 135, 133803 (2025)
Atomic, Molecular, and Optical Physics
Self-Reconstruction of Order Parameter in Spin-Triplet Superconductor ${\mathrm{UTe}}_{2}$
Article | Condensed Matter and Materials | 2025-09-24 06:00 EDT
Y. Tokiwa, P. Opletal, H. Sakai, K. Kubo, S. Kambe, E. Yamamoto, M. Kimata, S. Awaji, T. Sasaki, D. Aoki, Y. Yanase, Y. Tokunaga, and Y. Haga
We investigate the effect of easy-axis metamagnetic crossover on superconductivity in along the axis through measurements of ac susceptibility, magnetization, and the magnetocaloric effect. In ultraclean single crystals, we identify a field-induced phase transition within the superconducting …
Phys. Rev. Lett. 135, 136502 (2025)
Condensed Matter and Materials
Band Renormalization, Quarter Metals, and Chiral Superconductivity in Rhombohedral Tetralayer Graphene
Article | Condensed Matter and Materials | 2025-09-24 06:00 EDT
Guillermo Parra-Martínez, Alejandro Jimeno-Pozo, Võ Tiến Phong, Héctor Sainz-Cruz, Daniel Kaplan, Peleg Emanuel, Yuval Oreg, Pierre A. Pantaleón, José Ángel Silva-Guillén, and Francisco Guinea
Recently, exotic superconductivity emerging from a spin-and-valley-polarized metallic phase has been discovered in rhombohedral tetralayer graphene. To explain this observation, we study the role of electron-electron interactions in driving flavor symmetry breaking, using the Hartree-Fock (HF) appro…
Phys. Rev. Lett. 135, 136503 (2025)
Condensed Matter and Materials
Accurate Gauge-Invariant Tensor-Network Simulations for Abelian Lattice Gauge Theory in $(2+1)\mathrm{D}$: Ground-State and Real-Time Dynamics
Article | Quantum Information, Science, and Technology | 2025-09-23 06:00 EDT
Yantao Wu and Wen-Yuan Liu
We propose a novel tensor-network method to achieve accurate and efficient simulations of Abelian lattice gauge theories (LGTs) in for both ground-state and real-time dynamics. The first key is to identify a gauge canonical form of gauge-invariant tensor-network states, which already simplifi…
Phys. Rev. Lett. 135, 130401 (2025)
Quantum Information, Science, and Technology
Active Leakage Cancellation in Single Qubit Gates
Article | Quantum Information, Science, and Technology | 2025-09-23 06:00 EDT
Ben Chiaro and Yaxing Zhang
The ability to perform fast and accurate rotations between the computational basis states of quantum bits is one of the most fundamental requirements for building a quantum computer. Because physical qubits generally contain more than two levels, faster gates often result in a higher leakage rate ou…
Phys. Rev. Lett. 135, 130601 (2025)
Quantum Information, Science, and Technology
Trotterization is Substantially Efficient for Low-Energy States
Article | Quantum Information, Science, and Technology | 2025-09-23 06:00 EDT
Kaoru Mizuta and Tomotaka Kuwahara
Trotterization is one of the central approaches for simulating quantum many-body dynamics on quantum computers or tensor networks. In addition to its simple implementation, recent studies have revealed that its error and cost can be reduced if the initial state is closed in the low-energy subspace. …
Phys. Rev. Lett. 135, 130602 (2025)
Quantum Information, Science, and Technology
Quantum-Optimal Frequency Estimation of Stochastic ac Fields
Article | Quantum Information, Science, and Technology | 2025-09-23 06:00 EDT
Anirban Dey, Sara Mouradian, Cosmo Lupo, and Zixin Huang
Resolving frequencies in a time-dependent field is classically limited by the measurement bandwidth. Using tools from quantum metrology and quantum control may overcome this limit, yet the full advantage afforded by entanglement so far remains elusive. Here we map the problem of frequency measuremen…
Phys. Rev. Lett. 135, 130802 (2025)
Quantum Information, Science, and Technology
First Law of Binary Black Hole Scattering
Article | Cosmology, Astrophysics, and Gravitation | 2025-09-23 06:00 EDT
Riccardo Gonzo, Jack Lewis, and Adam Pound
A derivation of the first law of binary black hole scattering includes dissipative effects.
Phys. Rev. Lett. 135, 131401 (2025)
Cosmology, Astrophysics, and Gravitation
Bondi-Metzner-Sachs Particles
Article | Particles and Fields | 2025-09-23 06:00 EDT
Xavier Bekaert, Laura Donnay, and Yannick Herfray
We construct wave functions for unitary irreducible representations (UIRs) of the Bondi-Metzner-Sachs (BMS) group, i.e., BMS particles, and show that they describe quantum superpositions of (Poincaré) particles propagating on inequivalent gravity vacua. This follows from reconsidering McCarthy's cla…
Phys. Rev. Lett. 135, 131602 (2025)
Particles and Fields
Nature of ${χ}{c1}(3872)$ and ${T}{cc}^{+}(3875)$
Article | Particles and Fields | 2025-09-23 06:00 EDT
Nora Brambilla, Abhishek Mohapatra, Tommaso Scirpa, and Antonio Vairo
Two decades ago the state was discovered in the hadron spectrum with two heavy quarks. The discovery fueled a surge in experimental research, uncovering dozens of so called exotics states lying outside the conventional quark model, as well as theoretical investigations into new forms o…
Phys. Rev. Lett. 135, 131902 (2025)
Particles and Fields
Observation of $\mathrm{\Lambda}$ Hyperon Local Polarization in $p$-Pb Collisions at $\sqrt{s_{\mathrm{NN}} }=8.16\text{ }\text{ }\mathrm{TeV}$
Article | Nuclear Physics | 2025-09-23 06:00 EDT
A. Hayrapetyan et al. (CMS Collaboration)
The polarization of the and hyperons along the beam direction has been measured in proton-lead () collisions at a center-of-mass energy per nucleon pair of 8.16 TeV. The data were obtained with the CMS detector at the LHC and correspond to an integrated luminosity of . A sign…
Phys. Rev. Lett. 135, 132301 (2025)
Nuclear Physics
Superfluid Density in Linear Response Theory: Pulsar Glitches from the Inner Crust of Neutron Stars
Article | Nuclear Physics | 2025-09-23 06:00 EDT
Giorgio Almirante and Michael Urban
The question of whether there are enough superfluid neutrons in the inner crust of neutron stars to explain pulsar glitches remains a topic of debate. Previous band structure calculations suggest that the entrainment effect significantly reduces the superfluid density. In this Letter, a new derivati…
Phys. Rev. Lett. 135, 132701 (2025)
Nuclear Physics
Role of Matter Interactions in Superradiant Phenomena
Article | Atomic, Molecular, and Optical Physics | 2025-09-23 06:00 EDT
João Pedro Mendonça, Krzysztof Jachymski, and Yao Wang
The superradiant phenomenon, usually described by the Dicke model, is a hallmark of strong light-matter interaction. We explore how matter-matter interactions influence this phenomenon by performing ground-state simulations of Dicke-like models with both isotropic and anisotropic interactions. We fi…
Phys. Rev. Lett. 135, 133601 (2025)
Atomic, Molecular, and Optical Physics
Unraveling Dicke Superradiant Decay with Separable Coherent Spin States
Article | Atomic, Molecular, and Optical Physics | 2025-09-23 06:00 EDT
P. Rosario, L. O. R. Solak, A. Cidrim, R. Bachelard, and J. Schachenmayer
Scientists have shown that entanglement plays no role in a form of collective light emission called Dicke superradiance, settling a long-standing debate.
Phys. Rev. Lett. 135, 133602 (2025)
Atomic, Molecular, and Optical Physics
Toward Chaotic Group Velocity Hopping of an On-Chip Dissipative Kerr Soliton
Article | Atomic, Molecular, and Optical Physics | 2025-09-23 06:00 EDT
Grégory Moille, Sashank Kaushik Sridhar, Pradyoth Shandilya, Avik Dutt, Curtis Menyuk, and Kartik Srinivasan
Chaos enables randomness-based applications, particularly in photonic systems. Integrated optical frequency combs (microcombs) have previously been observed in either chaotic modulation instability or stable, low-noise dissipative Kerr soliton (DKS) regimes. In this Letter, we demonstrate a new micr…
Phys. Rev. Lett. 135, 133802 (2025)
Atomic, Molecular, and Optical Physics
Revealing Band-Hybrid Cooper Pairs on the Surface of a Superconductor with Spin-Orbit Coupling
Article | Condensed Matter and Materials | 2025-09-23 06:00 EDT
Javier Zaldívar, Jon Ortuzar, Miguel Alvarado, Stefano Trivini, Julie Baumard, Carmen Rubio-Verdú, Edwin Herrera, Hermann Suderow, Alfredo Levy Yeyati, F. Sebastian Bergeret, and Jose Ignacio Pascual
Most superconductors exhibit spin-singlet pairing within a single band. In multiband systems with strong spin-orbit coupling, more exotic scenarios can emerge, including Cooper pairs between bands with distinct symmetries. Here, we present evidence of the formation of Cooper pairs between spin-nonde…
Phys. Rev. Lett. 135, 136201 (2025)
Condensed Matter and Materials
Brillouin Platycosms and Topological Phases
Article | Condensed Matter and Materials | 2025-09-23 06:00 EDT
Chen Zhang, Peiyuan Wang, Junkun Lyu, and Y. X. Zhao
There exist ten distinct closed flat 3D manifolds, known as "platycosms," that hold significance in mathematics and have been postulated as potential geometric models for our Universe. In this Letter, we demonstrate their manifestation as universes of Bloch particles, namely as momentum-space units …
Phys. Rev. Lett. 135, 136601 (2025)
Condensed Matter and Materials
arXiv
Origin of pressure-induced anomalies in the nodal-line ferrimagnet Mn$_3$Si$_2$Te$_6$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Varun Venkatasubramanian, Makoto Shimizu, Daniel Guterding, Harald O. Jeschke
A pressure-induced insulator-to-metal transition (IMT) has recently been discovered in the nodal-line ferrimagnet Mn$ _3$ Si$ _2$ Te$ _6$ . The electronic phase transition is accompanied by anomalies in the magnetic ordering temperature and the anomalous Hall conductivity, which peak at or near the critical pressure of the IMT. We perform density functional theory (DFT) calculations as a function of pressure to reveal the driving factors behind the IMT and the magnetic anomalies in Mn$ _3$ Si$ _2$ Te$ _6$ . We extract Heisenberg Hamiltonians as a function of pressure based on our DFT calculations. Our classical Monte Carlo simulations for these Hamiltonians yield ordering temperatures and magnetic ordering patterns, in agreement with the experimental data. Although we can accurately explain the evolution of magnetism with pressure, it seems that the anomalous Hall conductivity in Mn$ _3$ Si$ _2$ Te$ _6$ cannot be accounted for by intrinsic contributions alone.
Strongly Correlated Electrons (cond-mat.str-el)
8+5 pages, 4+7 figures
SU(4) Kondo Lattice in Semiconductor Moiré Materials
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Motivated by recent advances in transition metal dichalcogenide (TMD) moiré materials, we propose TMD moiré multilayers as a platform for realizing an approximately SU(4)-symmetric triangular Kondo lattice, generalizing the concept of the double quantum dot model. Our model extends the conventional Kondo lattice by incorporating a three-site exchange of SU(4) local moments, which drives spontaneous time-reversal and lattice symmetry breaking. Using a parton mean-field approach, we map out the phase diagram as a function of three-site exchange and hole doping. In the Kondo-unscreened regime, we identify Mott insulating phases, including bond-ordered states and a chiral spin liquid. With increasing doping, Kondo hybridization gives rise to a heavy Fermi liquid that exhibits distinct patterns of lattice symmetry breaking, with or without topological responses. We conclude with directions for future study.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages, 4 figures. Supplementary material: 4 pages, 1 figure
Localization and topological signatures under periodic twisting
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-09-24 20:00 EDT
James Walkling, Antonio Štrkalj, F. Nur Ünal
We theoretically explore a dynamical generalization of the Aubry-André model in two dimensions formed by superimposing two square-lattice potentials. Motivated by the rich physics emerging at different twist angles between the two lattices at equilibrium, we introduce periodic twisting by continuously rotating one of the lattices with respect to the other in the plane. We demonstrate that the distinct time-dependent twisting in this system gives rise to an intricate form of periodic multi-frequency driving that changes with the distance from the rotation axis. We find that the incommensurate nature of the potential no longer plays the pivotal role as it does in the static case. Rather, the tunneling can be understood in terms of a local, spatially varying dynamical localization effect, which we show to yield ring-shaped states localized within the bulk that have interesting transport signatures. Quantifying the eigenstates with the Bott index and local Chern marker, we find that there is a zoo of states with non-trivial topological signatures, the most ubiquitous of which result in relatively uniform ring-shaped regions of the Chern marker. We investigate the origin of these effects from various angles and identify that hybridization between different delocalized ring states plays a vital role. Lastly, we discuss possible experimental realizations in quantum simulation settings. Our results open a new avenue of investigation with periodic twisting inducing a spatially varying multi-frequency drive.
Quantum Gases (cond-mat.quant-gas), Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
14+9 pages, 15+7 figures
Obtaining the Spectral Function of Moiré Graphene Heavy-Fermions Using Iterative Perturbation Theory
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Dumitru Călugăru, Haoyu Hu, Lorenzo Crippa, Gautam Rai, Nicolas Regnault, Tim O. Wehling, Roser Valentí, Giorgio Sangiovanni, B. Andrei Bernevig
The spectral functions of twisted bilayer graphene (TBG) in the absence of strain have recently been investigated in both the symmetric and symmetry-broken phases using dynamical mean-field theory (DMFT). The theoretically predicted Mott-Hubbard bands and gapless semimetallic state at half-filling have since been confirmed experimentally. Here, we develop several second-order perturbation theory approaches to the topological heavy-fermion (THF) model of TBG and twisted symmetric trilayer graphene (TSTG). In the symmetric phase, we adapt, implement, and benchmark an iterative perturbation theory (IPT) impurity solver within DMFT, enabling computationally efficient yet accurate spectral function calculations. We present momentum- and energy-resolved spectra over a broad range of temperatures and fillings for both symmetric and symmetry-broken states. In addition, we derive analytic expressions for the spectral function within the ``Hubbard-I’’ approximation of the THF model and, as expected, find that while it provides a tractable description of Mott physics, it does not capture the low-energy Kondo peak or the finite lifetime broadening of the bands. Our methodology can be extended to include strain, lattice relaxation, and parameter variations, thereby allowing systematic predictions of TBG and TSTG spectral properties across a wide range of physical regimes. Because our perturbative approaches are far less computationally intensive than DMFT with numerically exact impurity solvers, they can be used to efficiently benchmark and scan extensive phase diagrams of the THF parameters, paving the way for full DMFT analyses of the TBG spectral function in the presence of strain and relaxation.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
21+106 pages, 5+71 figures, 0+4 tables. See also arXiv:2402.14057
Instability of Laughlin FQH liquids into gapless power-law correlated states with continuous exponents in ideal Chern bands: rigorous results from plasma mapping
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Saranyo Moitra, Inti Sodemann Villadiego
We investigate the fate of Laughlin’s wave-function in ideal Chern bands which can be mapped to generalized zero Landau levels in spatially dependent magnetic fields. By exploiting its exact mapping onto a classical Coulomb gas and leveraging previous results of one-component plasmas in nonuniform neutralizing backgrounds, we demonstrate that the ideal Laughlin wave-function undergoes a phase transition from its well-known fully gapped topologically ordered plasma state into a power-law correlated dielectric state even for the fixed filling of $ 1/3$ , as the magnetic field becomes increasingly more inhomogeneous. This dielectric state is gapless even though it does not spontaneously break translational symmetry. Remarkably, for a fixed filling $ \nu=1/m$ , the exponent governing density correlations in this state changes continuously as a function of the degree of spatial inhomogeneity of the magnetic field, and can range from $ 4$ near a Berezinskii-Kosterlitz-Thouless transition to the plasma state, up to $ 2 m$ in the limit of fields generated by point solenoids.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech)
6+4 pages, 1+0 figures. Comments welcome!
Structures of group-15 elemental solids from an effective boundary theory
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
We present an effective description for the crystal structures of pnictogen elemental solids. In these materials, each atom contains three valence electrons in $ p$ orbitals. They are shared between neighbouring atoms to form valence bonds. We propose a trivalent network model on the simple cubic lattice. As a generalization of a dimer model, we impose a constraint that three dimers must touch every site. We argue that intra-orbital Coulomb repulsion prohibits the formation of two adjacent, parallel dimers. This leads to a tripod-like local configuration at every site. More importantly, it forces every line of the cubic lattice to have alternating dimers and blanks. There is no dynamics as dimers cannot be locally rearranged. A bulk-boundary mapping emerges whereby bonds in the interior are fully described by Ising variables on three bounding planes – a simple example of holography that may be realized in real materials. To describe the energetics of bonding, we formulate a minimal model in terms of boundary Ising spins. Symmetries reduce the problem to that of three identical, independent, two-dimensional Ising models. An antiferromagnetic Ising-ground-state corresponds to the A7 structure seen in antimony and grey arsenic. An antiferromagnetic phase within a bilayer describes the structure of phosphorene. By stacking such bilayers, we obtain the A17 structure of black phosphorus. The stripe phase of the Ising models describes the cubic gauche structure of nitrogen. As a testable signature, we demonstrate that single impurities will induce long-ranged domain walls.
Strongly Correlated Electrons (cond-mat.str-el)
11 pages, 15 figures
Cyclo-Graphyne: A Highly Porous and Semimetallic 2D Carbon Allotrope with Dirac Cones
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Jhionathan de Lima, Cristiano Francisco Woellner
We present a comprehensive characterization of Cyclo-graphyne (CGY), an emerging 2D carbon allotrope with a porous structure of sp/sp$ ^2$ -hybridized carbon atoms. Using density functional theory, we systematically investigate its structural, energetic, dynamical, thermal, electronic, mechanical, optical, and vibrational properties. The calculated cohesive and formation energies are both comparable to those of other synthesized graphynes, confirming its energetic viability. Phonon dispersion calculations confirm its dynamical stability, while ab initio molecular dynamics simulations indicate thermal stability up to at least 1000 K. Electronic results reveal that CGY is a semimetal with an ultranarrow band gap and features two Dirac cones in its electronic structure. Mechanically, CGY is highly compliant and isotropic, exhibiting a Young’s modulus an order of magnitude lower than that of graphene. The optical spectrum reveals strong ultraviolet absorption and infrared reflectivity with an isotropic response, while the vibrational spectra show distinct Raman peaks and rich infrared activity. These properties position CGY as a promising candidate for future applications in areas such as gas capture and separation, flexible nanoelectronics, and optoelectronics.
Materials Science (cond-mat.mtrl-sci)
The Frenkel line and the pseudogap: an analogy between classical and electronic fluids
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
J. Fournier, P.-O. Downey, O. Gingras, C.-D. Hébert, M. Charlebois, A.-M. S. Tremblay
Asymptotically close to critical end-points of first-order transitions, maxima in thermodynamic quantities occur along a line called the Widom line, a concept first introduced in classical fluids. This concept has been extended to strongly correlated electronic fluids in the context of the Mott transition. Namely, upon increasing interaction strength in the Hubbard model at half-filling, one finds a first-order Mott metal-insulator transition with a critical end-point at high temperature above which a number of crossover lines are observable. Using the dynamical cluster approximation for the triangular-lattice Hubbard model, we compute the Frenkel line, another concept borrowed from classical fluids, useful to define a sharp crossover between the pseudogap and the correlated Fermi liquid. The Frenkel line in the electron fluid is defined by the appearance of back-scattering when entering the pseudogap. The signature of back-scattering is the existence of a negative value in the time-domain optical conductivity.
Strongly Correlated Electrons (cond-mat.str-el)
4 pages, 6 figures, 2 pages of end matter, LaTeX
All-magnonic neurons for analog artificial neural networks
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
David Breitbach, Moritz Bechberger, Hanadi Mortada, Björn Heinz, Roman Verba, Qi Wang, Carsten Dubs, Mario Carpentieri, Giovanni Finocchio, Davi Rodrigues, Alexandre Abbass Hamadeh, Philipp Pirro
Analog neuromorphic hardware is gaining traction as conventional digital systems struggle to keep pace with the growing energy and scalability demands of modern neural networks. Here, we present analog, fully magnonic, artificial neurons, which exploit a nonlinear magnon excitation mechanism based on the nonlinear magnonic frequency shift. This yields a sharp trigger response and tunable fading memory, as well as synaptic connections to other neurons via propagating magnons. Using micro-focused Brillouin light scattering spectroscopy on a Gallium-substituted yttrium iron garnet thin film, we show multi-neuron triggering, cascadability, and multi-input integration across interconnected neurons. Finally, we implement the experimentally verified neuron activation function in a neural network simulation, yielding high classification accuracy on standard benchmarks. The results establish all-magnonic neurons as promising devices for scalable, low-power, wave-based neuromorphic computing, highlighting their potential as building blocks for future physical neural networks.
Materials Science (cond-mat.mtrl-sci)
17 pages, 6 figures
Interplay of Rashba and valley-Zeeman splittings in weak localization of spin-orbit coupled graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-24 20:00 EDT
Weak localization theory is developed for graphene heterostructures with transition metal dichalcogenides and topological insulators where the Rashba and valey-Zeeman spin-splittings of the energy spectrum are large enough. The anomalous magnetoresistance in low fields caused by weak localization is calculated. It is shown that the valley-Zeeman splitting has no effect on weak localization in the absence of Rashba splitting but it results in the change of the magnetoconductivity sign in the Rashba-coupled graphene. Inter-valley scattering also affects the quantum correction to the conductivity resulting in its sign reversal. Analytical expressions are obtained for the anomalous magnetoconductivity at arbitrary relations between the Rashba and valley-Zeeman splittings as well as the inter-valley scattering rates.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Disordered Systems and Neural Networks (cond-mat.dis-nn), Materials Science (cond-mat.mtrl-sci)
5+3 pages, 2 figures
Nonthermal magnetization pathways in photoexcited semiconductors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
The stabilization of long-range magnetic order in nominally non-magnetic semi- conductors using femtosecond light pulses is an exciting yet experimentally challenging goal. Theoretical studies indicate that certain non-magnetic semi- conductors can exhibit transient magnetic instabilities following above-gap laser excitation, but the dynamical pathways leading to these states remain largely unexplored. In this work, I introduce a minimal real-time spin-orbital model and identify the fundamental microscopic mechanisms that enable the emergence of a transient magnetic order. I then discuss the relevance of these findings for real materials employing a phenomenological time-dependent Ginzburg- Landau model. Finally, I analyze the strengths and limitations of current first-principles methodologies for investigating dynamically induced broken- symmetry states in the light of the present results.
Materials Science (cond-mat.mtrl-sci)
Quantifying the reactivity of isolated LixSi domains in Si anodes using operando NMR
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Evelyna Wang, Marco-Tulio F. Rodrigues, Baris Key
The use of Si anodes can greatly improve the energy density of Li-ion batteries. However, understanding and mitigation of calendar aging remains a barrier to commercialization. In this short report, we utilize operando Nuclear Magnetic Resonance (NMR) spectroscopy to detect and quantify lithium silicides (LixSi) as they form and react within Si anodes in pouch cells during calendar aging. We provide direct experimental evidence of complex aging phenomena in the Si anodes, including both SEI growth and dissolution during storage. Formation of electrochemically isolated LixSi is also observed, as indicated by the partial persistence of highly lithiated phases after the cell is discharged. Remarkably, we show that these isolated domains can themselves self-discharge over time, suggesting that their detection can be challenging in post-mortem studies. Finally, we show that aging outcomes depend heavily on the type of silicon particles contained within the electrode, and that certain surface coatings can help decrease the reactivity between lithium silicides and the electrolyte.
Materials Science (cond-mat.mtrl-sci)
Maze-solving with density-driven swarms
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-24 20:00 EDT
Esther María Zamora Sánchez, Sébastien Billès, Paul-Henry Glinel, Nicolas Bredeche, Raphaël Candelier
We propose a new kind of collective motion where swarms of simple agents are able to find and fix the solution of two-dimensional mazes. The model consists of active memoryless particles interacting exclusively via short-ranged perception of local density and orientations. This system generates traveling density waves when constrained in one dimension, and self-organized swarms exploring local branches in two-dimensional mazes. Depending on a single kinetic parameter, the swarms can develop large tails and further gain long-term persistence, which ultimately allows them to robustly solve mazes of virtually any kind and size. By systematic exploration of the parameter space, we show that there exists a fast solving regime where the resolution time is linear in number of squares, hence making it an efficient maze-solving algorithm. Our model represents a new class of active systems with unprecedented contrast between the minimality of the processed information and the complexity of the resolved task, which is of prime importance for the interpretation and modeling of collective intelligence in living systems as well as for the design of future swarms of active particles and robots.
Soft Condensed Matter (cond-mat.soft)
Spin currents in crystals with spin-orbit coupling: multi-band effects in an effective Hamiltonian formalism
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-24 20:00 EDT
K. V. Samokhin, M. Sigrist, M. H. Fischer
When focusing on a few essential bands in an effective description of a material to calculate observable quantities, the respective operators have to be adjusted accordingly. Ignoring contributions arising from integrating out remote bands can lead to qualitatively wrong results. We present a detailed analysis of the interband mixing effects on spin currents. Specifically, we calculate the intrinsic spin current in a time-reversal invariant noncentrosymmetric crystal in the presence of electron-lattice spin-orbit coupling. Starting from formally exact microscopic expressions, we derive the spin current operator restricted to one or more essential bands by iterative elimination of the contributions from distant bands. We show that the standard definition of the spin current operator in terms of the group velocity obtained from an effective band Hamiltonian cannot be justified using a microscopic theory. The modified expression for the spin current operator contains additional terms, which dominate the equilibrium spin current in a uniform crystal. We show that the magnitude of these additional terms can considerably exceed the spin current obtained using the standard definition.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
20 pages, 2 figures
Incommensurate magnetic order drives singular angular magnetoresistance in a Weyl semimetal
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
X. Yao, P. Chen, R. Verma, X. Zhao, H.-Y. Yang, L. DeBeer-Schmitt, A. A. Aczel, C.-M. Wu, D. Alba Venero, T. Ohhara, K. Munakata, M. Takahashi, Y. Noda, A. Bansil, B. Singh, P. Nikolić, F. Tafti, J. Gaudet
We demonstrate that a multi-$ \mathbf{k}$ incommensurate magnetic state in the Weyl semimetal CeAlGe gives rise to singular angular magnetoresistance (SAMR), an electrical-transport signature that detects the magnetic-field direction with exceptional precision. In contrast, the sister compound CeAlSi shows neither multi-$ \mathbf{k}$ order nor SAMR. Both phenomena emerge upon $ \sim57%$ Ge substitution in CeAlSi$ _{1-x}$ Ge$ _x$ and coincide with electronic-structure changes that soften the single-ion in-plane anisotropy and enhance Weyl-mediated magnetic interactions. These results reveal a direct connection between band topology, electronic transport, and collective magnetism in Weyl semimetals.
Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 4 figures. Submitted to Phys. Rev. Lett
Er$_\mathrm{Al}$:Al$_2$O$_3$ for Telecom-Band Photonics: Electronic Structure and Optical Properties
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Mahtab A. Khan, Jayden D. Craft, Hari P. Paudel, Yuhua Duan, Dirk R. Englund, Michael N. Leuenberger
Er-doped Al$ _2$ O$ _3$ is a promising host for telecom-band integrated photonics. Here we combine ab initio calculations with a symmetry-resolved analysis to elucidate substitutional Er on the Al site (Er$ _\mathrm{Al}$ ) in $ \alpha$ -Al$ _2$ O$ _3$ . First-principles relaxations confirm the structural stability of Er$ _\mathrm{Al}$ . We then use the local trigonal crystal-field symmetry to classify the Er-derived impurity levels by irreducible representations and to derive polarization-resolved electric-dipole selection rules, explicitly identifying the symmetry-allowed $ f$ \textendash$ d$ hybridization channels. Kubo–Greenwood absorption spectra computed from Kohn–Sham states quantitatively corroborate these symmetry predictions. Furthermore, we connect the calculated intra-$ 4f$ line strengths to Judd–Ofelt theory, clarifying the role of $ 4f$ \textendash$ 5d$ admixture in enabling optical activity. Notably, we predict a characteristic absorption near $ 1.47~\mu\mathrm{m}$ (telecom band), relevant for on-chip amplification and emission. To our knowledge, a symmetry-resolved first-principles treatment of Er:Al$ _2$ O$ _3$ with an explicit Judd–Ofelt interpretation has not been reported, providing a transferable framework for tailoring rare-earth dopants in wide-band-gap oxides for integrated photonics. Our results for the optical spectra are in good agreement with experimental data.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 4 figures
Observation via spin Seebeck effect of macroscopic magnetic transport from emergent magnetic monopoles
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Nan Tang, Stephan Glamsch, Aisha Aqeel, Ludwig Scheuchenpflug, Michael Schulze, Christoph Liebald, Daniel Rytz, Christo Guguschev, Manfred Albrecht, Philipp Gegenwart
Magnetic monopoles, elusive in high-energy physics, have been realised as emergent quasiparticles in solid-state systems, where their unique properties hold promise for novel spintronic applications. Magnetic monopoles have been invoked in diverse platforms, including skyrmion lattices, chiral magnets, soft ferromagnets, aritifical nanomagnets. Yet, a demonstration of their role in magnetic transport has remained elusive. Here, we report such an observation via the spin Seebeck effect in the bulk insulating pyrochlore oxide, spin ice $ \mathrm{Dy_2Ti_2O_7}$ . By applying a thermal gradient perpendicular to a $ [111]$ -oriented magnetic field, we detect a transverse spin Seebeck voltage marked by a dominant peak at the onset of monopole proliferation, accompanied by a secondary feature and frequency-dependent behavior. Our findings establish a direct link between monopole dynamics and magnetic transport in an insulating medium, establishing a new pathway for probing fractionalized excitations and advancing towards novel spintronic applications.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Primary category justification: This work focuses on emergent monopole dynamics in the bulk frustrated pyrochlore Dy_2Ti_2O_7, establishing their role in magnetic transport. The core contribution is to strongly correlated/frustrated magnetism (this http URL-el). We use the spin Seebeck effect just as a probe; for discoverability we have cross-listed to this http URL-hall
Generation of pure, spin polarized, and unpolarized charge currents at the few cycle limit of circularly polarized light
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-24 20:00 EDT
Deepika Gill, Sangeeta Sharma, Sam Shallcross
In certain members of the transition metal dichalcogenide (TMDC) family, laser pulses of oppositely circularly polarized light excite electrons of opposite spin. Here we show that in the few cycle limit such pulses generate not only a spin density excitation, but also a spin current excitation. Employing the example of the TMDC WSe$ _2$ we show that pure spin currents, the flow of spin in the absence of net charge flow, 100% spin polarized currents, and charge currents are all accessible and controllable by tuning the amplitude of ~ 5 femtosecond gap tuned light pulses. Underpinning this physics is a symmetry lowering of the valley charge excitation from C3 at long duration to C2 in the few cycle limit, imbuing the excitation with net current. Our results both highlight the emergence of a rich light-spin current coupling at ultrafast times in the TMDC family, as well presenting a route to the all-optical generation of pure spin currents.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Localized Excitons and Landau-Level Mixing in Time-Reversal Symmetric Pairs of Chern Bands
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Guopeng Xu, Nemin Wei, Inti Sodemann Villadiego, Chunli Huang
We study Landau-level mixing in a time-reversal-symmetric Hamiltonian composed of two sets of Landau levels with opposite magnetic field, relevant to moiré minibands in twisted homobilayer transition-metal dichalcogenides in the adiabatic limit, where electrons in opposite valleys have flat Chern bands with opposite Chern numbers. Strong spin-orbit coupling polarizes spins in opposite directions in opposite valleys, separating Coulomb interactions into like-spin ($ V^{\uparrow\uparrow}$ ) and opposite-spin ($ V^{\uparrow\downarrow}$ ). Using degenerate perturbation theory, we compute Landau-level mixing corrections to $ V^{\uparrow\uparrow}$ and $ V^{\uparrow\downarrow}$ for different filling fractions. In the lowest Landau level, screening exhibits an even-odd effect: $ V^{\uparrow\uparrow}$ is reduced more strongly than $ V^{\uparrow\downarrow}$ in even-$ m$ angular momentum Haldane pseudopotential and less strongly in odd-$ m$ angular momentum ones. In the first Landau level, the short-range part ($ m=0,1$ ) of $ V^{\uparrow\downarrow}$ is reduced comparably to $ V^{\uparrow\uparrow}$ , while the strongest spin anisotropy appears in the $ m=2$ pseudopotential. These novel short-range spin correlations have important implications for candidate correlated phases of fractional quantum spin Hall insulators. A distinctive feature of this time-reversal-symmetric Hamiltonian, absent in conventional quantum Hall systems, is that spin-flip excitations form localized quasiparticles. We compute their excitation spectrum and predict a non-monotonic dependence of the ordering temperature of Chern ferromagnetism in MoTe$ _2$ on the Landau-level mixing parameter.
Strongly Correlated Electrons (cond-mat.str-el)
28 pages, 6 figures, comments are welcome
Magnetic penetration depth in topological superconductors: Effect of Majorana surface states and application for UTe$_2$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-24 20:00 EDT
Kazuki Akuzawa, Jushin Tei, Ryoi Ohashi, Satoshi Fujimoto, Takeshi Mizushima
In this study, we examine how the orbital degrees of freedom of electrons and Majorana surface states influence the magnetic penetration depth in the superconductor UTe$ 2$ . We use a model involving two orbital electrons and consider superconducting states classified into irreducible representations of the $ D{2h}$ crystal symmetry: $ A_{u}$ , $ B_{1u}$ , $ B_{2u}$ , and $ B_{3u}$ . We first show that in bulk nodal superconductors, such as the $ B_{2u}$ state, the magnetic penetration depth for the screening current along the antinodal direction exhibits a $ T^2$ dependence, which significantly deviates from $ T^4$ expected from conventional theory. This anomalous exponent is attributed to quasiparticle contributions around the point nodes to the inter-orbital paramagnetic current. We then explore the roles of surface states. The fully gapped $ A_{u}$ state hosts Majorana surface states with cone-shaped dispersions, while Majorana Fermi arcs appear in the other pairing states. We demonstrate that when the ratio of magnetic penetration depth to coherence length ($ \kappa$ ) is small, the Majorana cone in the $ A_u$ state significantly contributes to the paramagnetic current, leading to the $ T^3$ dependence of the penetration depth. In the other states hosting Majorana arcs, the penetration depth exhibits anisotropic power-law behavior, such as $ T^2$ ($ T^3$ ) for the screening current flowing along the dispersive (dispersionless) direction of Majorana arcs. Therefore, in low-$ \kappa$ type-II superconductors, the signals of Majorana surface states may be detectable through penetration depth measurements. As $ \kappa$ increases and approaches the type-II limit, however, the impact of Majorana surface states diminishes, and the temperature dependence is determined by bulk quasiparticle excitations instead of surface states.
Superconductivity (cond-mat.supr-con)
11 pages, 8 figures
Influence of La-doping on the magnetic properties of the two-dimensional spin-gapped system SrCu$_2$(BO$_3$)$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Lia Šibav, Tilen Knaflič, Graham King, Zvonko Jagličić, Maja Koblar, Kirill Yu. Povarov, Sergei Zvyagin, Denis Arčon, Mirela Dragomir
Aliovalent doping of the two-dimensional dimer antiferromagnet SrCu$ _2$ (BO$ _3$ )$ _2$ has long been proposed as a potential route toward realizing resonating valence bond (RVB) superconductivity in this system; however, experimental progress has remained limited. This study explores the effects of La doping on the ground state of SrCu$ _2$ (BO$ _3$ )$ _2$ and reports the first flux growth of Sr$ _{1-x}$ La$ _x$ Cu$ _2$ (BO$ _3$ )$ _2$ single crystals with nominal doping levels up to $ x$ = 0.15. Powder X-ray diffraction and energy-dispersive X-ray spectroscopy confirm the successful incorporation of La on the Sr sites within the tetragonal $ I\bar{4}2m$ structure, although the effective doping was limited to approximately 50% of the nominal concentration. La doping induces systematic changes in the magnetic properties, with a reduction of the effective spin gap $ \Delta$ from ~28.2K to ~20.3 K at $ x$ = 0.15, as determined from low-temperature magnetic susceptibility. X-band electron spin resonance measurements reveal the emergence of unpaired Cu$ ^{2+}$ spins in La-doped SrCu$ _2$ (BO$ _3$ )$ _2$ single crystals, which develop antiferromagnetic correlations below ~5.5 K. These findings corroborate the breaking of the local spin dimers induced by La doping. Despite this, no superconductivity is observed across the entire doping range studied. The present study demonstrates that at low doping levels, electron doping locally destabilizes the spin-singlet ground state in SrCu$ _2$ (BO$ _3$ )$ _2$ , while the intrinsic spin dynamics of the dimer lattice remain largely preserved.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
38 pages, 17 figures, 5 tables
Spin-Axis Dynamic Locking
New Submission | Other Condensed Matter (cond-mat.other) | 2025-09-24 20:00 EDT
Lv Zhiheng, Ma Dengpan, Cai Jiangtao, Xing Yan, Liu Zhifeng
The all-electric realization of high spin polarization and efficient charge-to-spin remains a fundamental challenge in spintronics. We report a spin-axis dynamic locking (SADL) effect in altermagnets that enables fully spin-polarized axial currents: an inplane electric field along one axis drives a pure spin-up current, whereas along the orthogonal axis, it generates a pure spin-down current. Notably, a diagonal field produces a pure transverse spin current with 100% charge-to-spin conversion efficiency. This originates from extremely anisotropic sublattice hopping in a 2D altermagnetic lattice, forming a “tent state” with flat bands and orthogonal Fermi contours. Our firstprinciples calculations demonstrate SADL in a broad class of altermagnetic semiconductors (e.g., 2D Cr2WSe4 monolayer and synthesized 3D (BaF)2Mn2Se2O crystal). These materials provide ideal platforms for gate-tunable, all-electrical spintronics, enabling reconfigurable devices whose spin state is controlled solely by the orientation of an applied electric field.
Other Condensed Matter (cond-mat.other)
Zero-field Anomalous Hall Effect in Bulk Single Crystal Mn3Ir
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Xin Gu, Ruoqi Wang, Bo Zhao, Haofu Wen, Kunquan Hong, Shijun Yuan, Taishi Chen, Jinlan Wang
The L1_2-phase non-collinear antiferromagnet (AFM) Mn_3Ir has emerged as a pioneering platform for realizing the zero-field anomalous Hall effect (AHE), thereby catalyzing rapid advances in antiferromagnetic spintronics. Despite its significant potential, experimental investigations of the intrinsic magnetic and electronic properties of Mn_3Ir have been greatly hindered by the formidable challenges in growing bulk single crystals. Here, we report the growth of stoichiometric Mn_3Ir bulk single crystals and their characterization in terms of magnetization and the AHE. Using a high-throughput flux method, we obtained (111)-oriented hexagonal Mn_3Ir single crystals. A small AHE signal was detected, which we attribute to the coexistence of A- and B-type antiferromagnetic domains that mutually cancel the net AHE response. Our results reveal key aspects of the intrinsic magnetic properties and AHE in bulk Mn_3Ir, providing a critical material platform for the development of advanced spintronic devices.
Materials Science (cond-mat.mtrl-sci)
18 pages, 5 figures
Active Ornstein-Uhlenbeck particle under stochastic resetting
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-24 20:00 EDT
We investigate the dynamics of an inertial active Ornstein-Uhlenbeck (OU) particle in the presence of stochastic resetting. Using renewal approach, we compute the mean square displacement (MSD) and position probability distribution functions both in the overdamped and underdamped regimes. In contrast to the normal active OU particle, the MSD of an active OU particle with resetting displays an initial diffusive and long-time or steady-state non-diffusive behavior. The steady-state MSD gets suppressed with an increase in the resetting rate and approaches zero for an infinitely large resetting rate. Moreover, it has a nonmonotonic impact on the duration of activity. For an intermediate range of activity time, the steady-state MSD is enhanced, allowing the particle to explore a larger region, thereby increasing the probability of encountering a wide-spread target. Moreover, when the particle is suspended in a viscoelastic medium characterized by the presence of finite memory, the MSD interestingly develops an intermediate-time plateau and the plateau depends on the strength of the viscoelasticity and the viscoelastic relaxation time. With an increase in strength of the viscoelasticity, the width of the plateau increases and the MSD suppresses. In addition, slow viscoelastic relaxation makes memory effects weaker and hence the intermediate plateau disappears and steady state MSD gets enhanced, implying low strength and longer persistence of memory are beneficial for a wide spread target search. Similarly, for slow resetting, the intermediate plateau is more distinct, whereas fast resetting results in the system approaching steady state faster, overcoming the intermediate plateau in MSD. This emerging behavior might be due to the complex interplay between the resetting mechanism, activity, and memory effects. Finally, our analytical results are in good agreement with numerical simulation.
Soft Condensed Matter (cond-mat.soft)
15 pages, 9 figures
Direct measurement of coherent nodal and antinodal dynamics in underdoped Bi-2212
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-24 20:00 EDT
Rishabh Mishra, Jonathan O. Tollerud, Paolo Franceschini, Nikolas Stavrias, Fabio Boschini, Genda Gu, Andrea Damascelli, Daniele Fausti, Jared H. Cole, Claudio Giannetti, Jeffrey A. Davis
The physics of strongly correlated materials is deeply rooted in electron interactions and their coupling to low-energy excitations. Unraveling the competing and cooperative nature of these interactions is crucial for connecting microscopic mechanisms to the emergence of exotic macroscopic behavior, such as high-temperature superconductivity. Here we show that polarization-resolved multidimensional coherent spectroscopy (MDCS) is able to selectively drive and measure coherent Raman excitations in different parts of the Fermi surface, where the superconducting gap vanishes or is the largest (respectively called Nodal and Antinodal region) in underdoped Bi-2212. Our evidence reveal that in the superconducting phase, the energy of Raman excitations in the nodal region is anti-correlated with the energy of electronic excitations at $ \sim$ 1.6eV, and both maintain coherence for over 44fs. In contrast, excitations in the antinodal region show significantly faster decoherence ($ <$ 18~fs) and no measurable correlations. Importantly, this long-lived coherence is specific to the superconducting phase and vanishes in the pseudogap and normal phases. This anti-correlation reveals a coherent link between the transition energy associated with the many body Cu-O bands and the energy of electronic Raman modes that map to the near-nodal superconducting gap. The different coherent dynamics of the nodal and antinodal excitations in the superconducting phase suggest that nodal fluctuations are protected from dissipation associated with scattering from antiferromagnetic fluctuations and may be relevant to sustaining the quantum coherent behaviour associated with high temperature superconductivity.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el), Optics (physics.optics)
Strain-Tuned Optical Properties of a Two-Dimensional Hexagonal Lattice: Exploiting Saddle Degrees of Freedom and Saddle Filtering Effects
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-24 20:00 EDT
Phusit Nualpijit, Bumned Soodchomshom
The deformation of hexagonal lattices has attracted considerable attention due to its promising applications in straintronics. This study employs the tight-binding model to investigate the anisotropic spectrum, where electronic transport can be manipulated by the degree of deformation. The longitudinal conductivities, light transmittance, and absorbance are analyzed, revealing enhancement along one direction and suppression along the other. The findings indicate that the direction and magnitude of strain can be determined by measuring transmittance and absorbance, showing significant deviations from the unstrained condition. Furthermore, a strong absorbance is observed due to the interband transition of electrons near the M-point saddles, linked to van Hove singularities for specific values of nearest and next-nearest hoping energy. The unexpected characteristics of saddle polarization-analogous to valley polarization at K- and K’-become particularly prominent when strain affects the selection of M-point saddle. Notably, the demonstration indicates that a highly efficient M-point saddle filtering effect takes place, induced by linearly polarized light. This model paves the way for exploring the optical properties of anisotropic hexagonal lattices, such as black phosphorus and borophene oxide. These results also open a pathway to strain-programmable optoelectronic devices, such as polarization-selective photodetectors, tunable absorbers, and ultrathin optical filters.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
22 pages, 12 Figures
Optical properties of RCd3P3 (R: Ce or La) compounds: Insulator-metal transition induced by displacement of atoms in the unit cell
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Jaekyung Jang, Yu-Seong Seo, Jeonghun Lee, Eundeok Mun, Jungseek Hwang
We examined the electronic structures and optical properties of single crystals of RCd3P3 (R = Ce or La). Our first-principles analysis indicates that CeCd3P3 and LaCd3P3 exhibit semiconductor characteristics with narrow energy gaps of approximately 0.51 and 0.70 eV, respectively. Notably, a slight displacement of the Cd and P atoms within the unit cell significantly transforms the electronic structure from insulating to metallic state. Optical spectroscopy of both compounds reveals a metallic state with a low charge carrier density, suggesting a finite density of states at the Fermi level. A comparison between the theoretical electronic structures and experimental optical properties elucidates the observed metallic behavior. Additionally, the notable modification of the infrared-active phonons strongly indicates a structural phase transition in these compounds. Our findings also suggest that CeCd3P3 serves as a suitable platform for investigating the photoinduced Kondo effect due to its metallic ground state with limited charge carriers.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
20 pages, 5 figures
NPG Asia Materials 17, 36 (2025)
Optical properties of popular dielectric substrate materials in a wide spectral range from far-infrared to ultraviolet
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Minjae Kim, Hong Gu Lee, Jungseek Hwang
We investigated the optical properties of 13 different dielectric materials (slide glass, quartz, Al2O3 (c-cut), DyScO3 (110), KTaO3 (001), LaAlO3 (001), (LaAlO3)0.3-(Sr2AlTaO6)0.7 (001) (LSAT), MgF2 (100), MgO (100), SiC, SrTiO3 (001), TbScO3 (110), and TiO2). The single-bounce reflectance spectra of the bulk samples were measured using Fourier transform infrared (FTIR) and monochromatic spectrometers across a wide spectral range, from far infrared to ultraviolet (80-50,000 cm-1). Using the Kramers-Kronig analysis, we obtained the optical conductivity and dielectric function of the dielectric materials from their measured reflectance spectra. Moreover, we measured the transmittance spectra of the materials to obtain their bandgaps. We fitted the measured reflectance spectra using the Lorentz model to obtain phononic structures. Each dielectric material exhibits unique phononic structures and optical bandgaps, associated with the composition and crystal structure of the material. The observed optical properties of these dielectric materials provide valuable information for the optical analysis of thin films grown on them.
Materials Science (cond-mat.mtrl-sci)
16 pages, 6 figures
Current Applied Physics 67, 115-122 (2024)
Exceptional-point-induced dynamic sensitivity to particle-number parity
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
As an exclusive feature of a non-Hermitian system, the existence of exceptional points (EPs) depends not only on the details of the Hamiltonian but also on the particle-number filling and the particle statistics. In this paper, we study many-particle EPs in a Bose Hubbard chain with two end-site resonant imaginary potentials. Starting from a single-particle coalescing eigenstate, we construct $ n$ -particle condensate eigenstates for the cases with zero and infinite $ U$ . Compared with the free bosonic case, where the $ n $ -particle condensate eigenstate is an $ (n+1)$ -th-order coalescing state, the hardcore-boson counterpart is a second-order coalescing state for odd $ n$ , while it is not for even $ n$ . The difference in particle-number parity results in distinct quenching dynamics of the condensate states, highlighting the role of parity in system behavior. Our finding may stimulate research on the dynamic sensitivity to particle-number parity.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
A scaling law for large-deformation contact in soft materials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-24 20:00 EDT
Tong Mu, Shizhuo Weng, Changhong Linghu, Ruozhang Li, Jingyi Yu, Zhonghao Xu, Yingjie Fu, Lin Yang, Domenico Campolo, Yanju Liu, Jinsong Leng, K. Jimmy Hsia, Huajian Gao
Compression of soft bodies is central to biology, materials science, and robotics, yet existing contact theories break down at large deformations. Here, we develop a general framework for soft-body compression by extending the method of dimensionality reduction into the nonlinear regime. Analytical solutions for contact force and radius are derived and validated against finite element simulations and experiments on canonical geometries (cone, hemisphere, cylinder), achieving high accuracy up to 50% compression. From this framework emerges a universal scaling law that unifies the nonlinear force-displacement response across diverse shapes and even irregular soft objects such as gummy candies. Leveraging this principle, we design a vision-based tactile sensor that reconstructs real-time pressure maps and enables delicate robotic manipulation of fragile items. By bridging nonlinear contact mechanics with practical sensing, this work both advances fundamental understanding of large-strain mechanics and opens a route to robust tactile technologies for soft robotics and biomedical applications.
Soft Condensed Matter (cond-mat.soft)
Large Anomalous and Topological Hall Effect and Nernst Effect in a Dirac Kagome Magnet Fe3Ge
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Chunqiang Xu, Shuvankar Gupta, Hengxin Tan, Hyeonhu Bae, Olajumoke Oluwatobiloba Emmanuel, Mingyu Xu, Yan Wu, Xiaofeng Xu, Pengpeng Zhang, Weiwei Xie, Binghai Yan, Xianglin Ke
The search for kagome magnets with unconventional magnetic and electronic properties has gained significant attention in recent years. We report the magnetic, electronic, and thermoelectric properties of Fe3Ge single crystals, where the Fe atoms form a slightly distorted kagome lattice. Fe3Ge exhibits a large anomalous Hall effect and anomalous Nernst effect. The anomalous transverse thermoelectric conductivity reaches about 4.6 A m^-1 K^-1, exceeding values reported for conventional ferromagnets and most topological ferromagnets. First-principles calculations indicate that these transport responses are primarily governed by intrinsic mechanisms, highlighting the dominant role of Berry curvature arising from massive Dirac gaps in momentum space. In addition, we observe a topological Hall resistivity of about 0.9 microOhm cm and a topological Nernst coefficient of 1.2 microvolt K^-1, which are attributed to the Berry phase associated with field-induced scalar spin chirality. These findings demonstrate the combined influence of Berry phases in both momentum and real space, establishing Fe3Ge as a promising candidate for room-temperature transverse thermoelectric applications.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Accepted in Advanced Functional Materials
A closed-loop AI framework for hypothesis-driven and interpretable materials design
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Kangyu Ji, Tianran Liu, Fang Sheng, Shaun Tan, Moungi Bawendi, Tonio Buonassisi
Scientific hypothesis generation is central to materials discovery, yet current approaches often emphasize either conceptual (idea-to-data) reasoning or data-driven (data-to-idea) analysis, rarely achieving an effective integration of both. Here, we present a generalizable active learning workflow that integrates top-down, theory-driven hypothesis generation, guided by a large language model. This is complemented by bottom-up, data-driven hypothesis testing through a root-cause association study. We demonstrate this approach through the design of equimolar quinary-cation two-dimensional perovskite, a chemically complex system with over 850,000 possible cation combinations. In the top-down component, the large language model drives closed-loop optimization by proposing candidates that are likely to achieve phase purity, leveraging domain knowledge and chain-of-thought reasoning. With each iteration, the model identifies an increasing number of near phase-pure compositions, sampling less than 0.004% of the design space. In parallel, the bottom-up association study identifies molecular features with statistically significant influences on phase purity. The integration of these approaches enables the convergence of conceptual and statistical hypotheses, leading to generalizable and rational design rules for phase-pure quinary-cation two-dimensional perovskites. As a proof of concept, we applied the optimized phase-pure quinary-cation two-dimensional perovskite film as a surface capping layer in perovskite solar cells, achieving good performance and stability. Our framework enables the development of interpretable and generalizable design rules that are applicable to a wide range of optimization processes within complex design spaces, providing a foundational strategy for rational, scalable, and efficient materials discovery.
Materials Science (cond-mat.mtrl-sci)
Octahedral dynamics and local symmetry in hybrid perovskite FAPbI3 under thermal excitation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
H. Joshi, K. C. Bhamu, A. Shankar, Rana Biswas, M. Wlazło
Density Functional Theory (DFT) and ab initio molecular dynamics (AIMD) simulations have been employed to investigate the evolution of local motifs within the tetragonal phase of FAPbI3 under thermal excitation. Our results reveal a distinct broadening in the distribution of PbI6 octahedral volumes with increasing temperature, indicating a gradual breakdown of symmetry and emergence of diverse local environments. These octahedral volume distortions are primarily driven by the dynamic behaviour of the FA cation leading to softening of PbI6 octahedra, evident from calculated mean octahedral volume and Pb-I-Pb bond angles. The examination of electronic structure confirmed that this dynamic structural phenomenon is directly responsible for the change in fundamental band gap value, highlighting the role of PbI6 octahedra in modifying and modulating the electronic properties in FAPbI3. The results demonstrate the microscopic origin of thermally induced dynamical behaviour to the macroscopic electronic properties and underscore the pivotal role of local motifs in hybrid perovskites.
Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
14 pages, 5 figures
Quaternary crystals CdZnTeSe: Growth via the vertical Bridgman method with different compositions of raw materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
S.V. Naydenov, O.K. Kapustnyk, I.M. Pritula, D.S. Sofronov, I.S. Terzin, N.O. Kovalenko
Indium-doped semiconductor crystals CdZnTeSe with several different compositions of raw materials were grown via the vertical Bridgman method under high-pressure argon. For the first time, these crystals were obtained via a combined method from a mixture of simple and binary starting components. A theoretical analysis of the permissible reactions for obtaining multicomponent CdZnTeSe crystals from different compositions of starting materials was performed. The homogeneity of the distribution of the atomic composition and electrical resistance (in the dark and under illumination) of the obtained crystals was studied. Crystals grown via the new combined method presented the best homogeneity of composition and electrophysical properties.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
12 pages, 7 figures
Beyond Bloch: A Theoretical Blueprint for Conjugated Polymer Optoelectronics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Miguel Lagos, Miguel Kiwi, Rodrigo Paredes
Conjugated polymers are experiencing a surge of renewed interest due to their promising applications in various organic electronic devices. These include organic light-emitting diodes (OLEDs), field-effect transistors (FETs), and organic photovoltaic (OPV) devices, among many others. Their appeal stems from distinct advantages they hold over traditional inorganic semiconductors. Unlike inorganic semiconductors, where electrons are often considered to be in delocalized, free, or quasi-free states (as described by Bloch’s theory), electrons in conjugated polymers behave differently. They are strongly coupled within highly localized $ \sigma$ or $ \pi$ -orbitals and interact significantly with the ionic cores. This means they are far from the idealized delocalized states presumed by Bloch’s theory approaches. Consequently, after nearly a century of applying Bloch’s theory to the electronic transport properties of inorganic materials, there is a clear need for a new theoretical framework to explain efficient charge transport in these organic solids. Our presented model addresses this need by incorporating crucial electron-electron interactions. Specifically, it accounts for both intra-site interactions and interactions between the $ \pi$ -states located at alternating sites along the polymer chain. This framework provides a many-body charge conduction mechanism and explains the semiconducting properties of the undoped material. A significant outcome of our model is the prediction of two novel flat bands of excited bonding states. Intriguingly, these states obey Bose–Einstein statistics and facilitate charge transport. Furthermore, our model accurately reproduces experimental data, providing an excellent fit for measured UV-Vis absorption and electroluminescent spectra.
Materials Science (cond-mat.mtrl-sci)
A basis-free, octonionic criterion for Weyl points in solids
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Conventional diagnostics of Weyl points – Berry flux on small spheres and $ k \cdot p$ linearization – are topologically sound but depend on user choices (sphere center and radius, gauge smoothing, charting, and local frame transport) that introduce algorithmic arbitrariness in first-principles workflows. We propose a \emph{local, basis-free} criterion built from the octonionic structure on $ \mathbb{R}^7$ . From a smooth two-band projector we construct a unit octonion field and its octonionic connection; contracting three directional derivatives with the $ \mathrm{G}_2$ –invariant three-form yields a pseudoscalar density whose sign equals the Weyl chirality. A vanishing octonionic associator at leading order certifies that the local problem closes inside an associative (quaternionic) three-plane, while a nonzero density identifies a Weyl point. The construction is invariant under $ \mathrm{SU}(2)$ gauge changes of the two-band subspace and under $ \mathrm{G}_2$ rotations of its completion, and it eliminates enclosing surfaces and gauge-seam choices. In the linear regime we prove equivalence with the conventional diagnostics (Chern charge on a small sphere and $ \mathrm{sgn}\det v$ ). We outline a practical algorithm compatible with Wannier tight-binding Hamiltonians and provide self-consistency checks based on stencil refinement and the associator norm. The \emph{octonionic Weyl point criterion} streamlines chirality assignment in high-throughput searches and offers an intrinsic warning signal in the presence of band entanglement or proximity to multi-fold touchings.
Materials Science (cond-mat.mtrl-sci), Mathematical Physics (math-ph)
Spin defects in hexagonal boron nitride as two-dimensional strain sensors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Z. Mu, Z. Zhang, J. Fraunié, C. Robert, G. Seine, B. Gil, G. Cassabois, V. Jacques
Lattice deformation is a powerful way to engineer the properties of two-dimensional (2D) materials, making their precise measurement an important challenge for both fundamental science and technological applications. Here, we demonstrate that boron-vacancy (V$ _\text{B}^-$ ) color centers in hexagonal boron nitride (hBN) enable quantitative strain sensing with sub-micrometer spatial resolution. Using this approach, we precisely quantify the strain-induced shift of the E$ _{\rm 2g}$ Raman mode in a hBN flake under uniaxial stress, establishing V$ _\text{B}^-$ centers as a new tool for strain metrology in van der Waals heterostructures. Beyond strain sensing, our work also highlights the unique multimodal sensing functionalities offered by V$ _\text{B}^-$ centers, which will be valuable for future studies of strain-engineered 2D materials.
Materials Science (cond-mat.mtrl-sci)
6 pages, 4 figures
Chemically Active Liquid Bridges Generate Repulsive Forces
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-24 20:00 EDT
Noah Ziethen, Frieder Johannsen, David Zwicker
Droplets help organize cells by compartmentalizing biomolecules and by mediating mechanical interactions. When bridging two structures, such droplets generate capillary forces, which depend on surface properties and distance. While the forces exerted by passive liquid bridges are well understood, the role of active chemical reactions, which are often present in biological droplets, remains unclear. To elucidate this case, we study a single liquid bridge with continuous chemical turnover. These reactions control the bridge radius and lead to purely repulsive forces-contrasting with the typically attractive forces in passive systems. Our results reveal how chemical activity can fundamentally alter forces generated by liquid bridges, which could be exploited by cells.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
11 pages, 5 figures
Signature of chiral superconducting order parameter evidenced in mesoscopic superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-24 20:00 EDT
Xiaoying Xu, Wei Qin, Yuelin Shen, Zixuan Huang, Zhuoya Zhou, Zirao Wang, Yufan Li
Chiral superconductivity is a novel superconducting phase characterized by order parameters that break the time-reversal symmetry, endowing the state with a definite handedness. Unlike conventional superconductors, the Cooper pairs in a chiral superconductor carry nonzero orbital angular momentum. Through coupling with an external magnetic field, the finite angular momentum of the Cooper pair modulates the temperature-magnetic field phase boundary in a distinctive way, which could serve as an experimental signature of the chiral superconducting state. Here we demonstrate that the chiral signature can be detected in mesoscopic superconducting rings of $ \beta$ -Bi$ _2$ Pd, manifesting as a linear-in-field modulation of the critical temperature in the Little-Parks effect. Our findings establish a new experimental method for detecting the chiral superconductivity.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Asymmetrical Defect Sink Behaviour of HCP/BCC Zr/Nb Multilayer Interfaces: Bubble-Denuded Zones at Nb Layers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Nabil. Daghbouj, H.S. Sen, Mohamed BenSalem, Jan.Duchoňc, Bingsheng. Li, Miroslav. Karlík, F. Ge, Vladimir. Krsjak, Petr. Báborh, M.O. Liedke, M. Butterling, Alexandre. Wagner, Bora. Karasulub, Tomas. Polcarak
Radiation induced helium bubble formation poses a major challenge to the structural integrity of materials in nuclear energy systems. In this study, we investigate defect evolution and He behavior in ZrNb nanoscale metallic multilayers with immiscible BCC and HCP interfaces, irradiated with 80 keV He ions. For comparison, single crystal Nb and polycrystalline Zr were also irradiated under identical conditions to serve as reference materials. Using cross sectional TEM, SIMS, STEM EELS, nanoindentation, Doppler Broadening Positron Annihilation Spectroscopy, Positron Annihilation Lifetime Spectroscopy, and atomistic simulations, we reveal a highly asymmetric damage response across the multilayer interfaces. Zr layers exhibit larger He bubbles, higher swelling, and greater helium retention while Nb layers develop bubble-denuded zones exclusively around the interfaces, where bubble nucleation is strongly suppressed and swelling is limited. This asymmetry arises from differences in atomic transport properties DFT calculations show lower migration barriers for vacancies and He atoms in Nb, enabling efficient defect migration and recombination at interfaces, whereas Zr retains defects due to higher migration barriers. EELS and DBS PALS measurements confirm bubble densities and the presence of sub-nanometer open volumes. Compared to monolithic samples, the ZrNb multilayers exhibit lower irradiation induced hardening and reduced He retention. These findings highlight the role of interfaces in driving asymmetric radiation damage and demonstrate the effectiveness of BCC Nb layers in mitigating defect growth. Overall, ZrNb multilayers are established as a superior alternative to conventional single and polycrystalline materials for extreme irradiation environments.
Materials Science (cond-mat.mtrl-sci)
18 figures, 48 pages
Acta Materialia 2025
Complex Frequency Fingerprint: Interacting Driven Non-Hermitian Skin Effect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-24 20:00 EDT
Zhesen Yang, Zihan Wang, Juntao Huang, Zijian Zheng, Jiangping Hu
The excitation properties of quantum many-body systems are encoded in their response functions. These functions define an associated response Hamiltonian, which is intrinsically non-Hermitian due to the dissipative nature of retarded responses, even in closed systems. By analyzing its eigenvalues and eigenstates, one obtains a unique characterization of the system, referred to as the complex frequency fingerprint. Using this framework, we demonstrate that interactions alone can give rise to both point-gap topology and the non-Hermitian skin effect. Unlike the dissipation-induced skin effect, this interaction-driven phenomenon exhibits pronounced frequency dependence. We further introduce a complex-frequency density of states framework that distinctly separates non-Hermitian skin modes from topological edge modes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 3 figures,
Quantum-to-classical transition and H-theorem in surface diffusion
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
E. E. Torres-Miyares, S. Miret-Artés
In this work, surface diffusion is studied with a different perspective by showing how the corresponding open dynamics is transformed when passing, in a continuous and smooth way, from a pure quantum regime to a full classical regime; the so-called quantum-to-classical transition. This continuous process is carried out from the Liouville-von Neumann equation by scaling Planck’s constant. For this goal, the Brownian motion of an adsorbate on a flat surface is analyzed in order to show how this transition takes place. In particular, this open dynamics is studied from the master equation for the reduced density matrix within the Caldeira-Leggett formalism; in particular, the two extreme time behaviors, the ballistic and diffusive motions. It is also shown that the origin of the ballistic motion is different for the quantum and classical regimes. In this scenario, the corresponding Gaussian function for the intermediate scattering function is governed by the thermal velocity in the classical regime versus the initial spreading velocity of the wave packet for the quantum regime, leading to speak of classical and quantum ideal gas, respectively. Finally, in the diffusive regime, and starting from the Chudley-Elliott model, the quantum-to-classical transition is also discussed in terms of the well-known H-function for three surface temperatures in the diffusion of H and D on a Pt(111) surface. The main goal in this analysis is if one can discriminate the irreversibility coming from tunneling and thermal activation diffusion.
Materials Science (cond-mat.mtrl-sci)
3 figures
Interacting-cluster spin liquids with robust flat bands evolving into higher-rank half-moon phases and topological Lifshitz transitions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Naïmo Davier, Ludovic D.C. Jaubert
Classical spin liquids are disordered magnetic phases, governed by local constraints that often give rise to flat-band ground states. When constraints take the form of a zero-divergence field within a cluster of spins, the spin liquid is often described by an emergent Coulomb gauge theory. Here we introduce an interaction $ \eta$ between these clusters of spins which compete with the zero-divergence field. Using a framework embracing both the connectivity matrices of graph theory and the topology of band structures, we develop a generic theory of interacting-cluster Hamiltonians. We show how flat bands remain at zero energy up to finite interaction $ \eta$ , until a dispersive band becomes negative, stabilizing a spiral spin liquid with a hypersurface of ground-state manifold in reciprocal space. This hypersurface serves as a mold for the apparition of the half-moon patterns in the equal-time structure factor. Our generic approach enables to extend the notion of half moons to the perturbation of higher-rank Coulomb fields and pinch-line spin liquids. In particular, multi-fold half moons appear when unconventional gauge charges, such as potential fractons, are stabilized in the ground state. Finally, half-moon phases can be tuned across the equivalent of a Lifshitz transition, when the hypersurface manifold changes topology.
Strongly Correlated Electrons (cond-mat.str-el)
21 pages, 8 figures, 1 table
Sub-nanosecond heat-based logic, writing and reset in an antiferromagnetic magnetoresistive memory
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
M. Surynek, A. Farkas, J. Zubac, P. Kubascik, K. Olejnik, F. Krizek, L. Nadvornik, T. Ostatnicky, R.P. Campion, V. Novak, T. Jungwirth, P. Nemec
Thermal logic aims to create thermal counterparts to electronic circuits. In this work, we investigate experimentally the response of an analog memory device based on a thin film of an antiferromagnetic metal CuMnAs to bursts of heat pulses generated by the absorption of femtosecond laser pulses at room ambient temperature. When a threshold temperature in the heat-based short-term memory of the device is exceeded, the output of the in-memory logic operations is transferred within the same device to a long-term memory, where it can be retrieved at macroscopic times. The long-term memory is based on magnetoresistive switching from a reference low-resistive uniform magnetic state to high-resistive metastable nanofragmented magnetic states. The in-memory heat-based logic operations and the conversion of the outputs into the electrically-readable long-term magnetoresistive memory were performed at sub-nanosecond time scales, making them compatible with the GHz frequencies of standard electronics. Finally, we demonstrate the possibility of rapidly resetting the long-term memory to the reference low-resistive state by heat pulses.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
v1: preprint; licence: CC BY 4.0; Supplementary material is a part of this submission
Giant optical anisotropy in CrSBr from giant exciton oscillator strength
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Georgy Ermolaev, Tagir Mazitov, Arslan Mazitov, Adilet Toksumakov, Dmitriy Grudinin, Anton Minnekhanov, Gleb Tselikov, Dmitry Yakubovsky, Gleb Tikhonowski, Nikolay Pak, Umer Ahsan, Aleksandr Slavich, Mikhail Mironov, Alexey Tsapenko, Andrey Vyshnevyy, Ivan Kruglov, Zdenek Sofer, Aleksey Arsenin, Kostya Novoselov, Andrey Katanin, Valentyn Volkov
The interplay between dimensionality and electronic correlations in van der Waals (vdW) materials offers a powerful toolkit for engineering light-matter interactions at the nanoscale. Excitons, bound electron-hole pairs, are central to this endeavor, yet maximizing their oscillator strength, which dictates the interaction cross-section, remains a challenge. Conventional wisdom suggests a trade-off, where the observable oscillator strength often decreases in strongly bound systems due to population dynamics. Here, we unveil a colossal oscillator strength associated with the quasi-one-dimensional (quasi-1D) excitons in the layered magnetic semiconductor CrSBr, which fundamentally defies this established scaling law. Through comprehensive optical characterization and ab initio calculations, we establish that this anomalous enhancement originates directly from the reduced dimensionality, which enforces an increased electron-hole wavefunction overlap. Moreover, we find a close connection between fundamental exciton and local spin fluctuations that contribute to the opening of the gap in the electronic spectrum. The resulting optical anisotropy shows a giant in-plane birefringence (Delta_n = 1.45) and profoundly anisotropic waveguiding, which we directly visualize using nano-optical imaging. Leveraging this extreme response, we realize a true zero-order quarter-wave plate with an unprecedented wavelength-to-thickness ratio (lambda/t) exceeding 3.4, surpassing the limits of current miniaturization technologies, including state-of-the-art metasurfaces. Our findings underscore the profound impact of dimensionality engineering in magnetic vdW materials for realizing novel regimes of light-matter coupling and developing next-generation ultracompact photonic architectures.
Materials Science (cond-mat.mtrl-sci)
13 pages, 5 figures
Spectroscopic Evidence for Electron-Boson Coupling in Half-metallic CrO2
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Daiki Ootsuki, Hirokazu Fujiwara, Noriyuki Kataoka, Kensei Terashima, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, Shiv Kumar, Shin-ichiro Ideta, Kenya Shimada, Yuji Muraoka, Takayoshi Yokoya
We report the electronic structure of the half-metal ferromagnet CrO2 by means of high-resolution angle-resolved photoemission spectroscopy (ARPES). The observed clear Fermi surface (FS) and band dispersion are in good agreement with the previous reports. Moreover, the ARPES band dispersion reveals a distinct kink structure around 68 meV, providing the first evidence from the electronic structure for the elementary excitations in CrO2. The energy scale of this feature is comparable to the Debye temperature and the A1g phonon mode, suggesting the electron-phonon interaction. From the detailed analysis, we have extracted the self-energy and found two characteristic structures in the real part of the self-energy. Assuming the existence of the electron-magnon interaction as well as the electron-phonon interaction, we have simulated the line shape for the real and imaginary parts of the self-energy and reproduced the ARPES intensity. Our spectral findings demonstrate the renormalized quasiparticle (QP) dynamics in CrO2 and provide valuable insights into the fundamental many-body interactions governing half-metallic ferromagnets.
Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 3 figures
Chemistry and physics of layered oxychalcogenides containing an anti-cuprate type square lattice
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
There has been significant recent interest in layered solid-state materials containing an [M2O] square lattice layer (M = transition metal), particularly because [M2O] is the anti-type of the [CuO2] planes in the layered cuprate superconductors. In addition to the superconducting titanium oxypnictides, the [M2O] anti-cuprate layer also occurs in a wide range of layered oxychalcogenide compounds with M spanning early (Ti, V) to later transition metals (Mn, Co, Fe). The chalcogenide in question - which sandwiches the anti-cuprate layer - may be S, Se or Te, and in combination with a wide range of intervening “spacer” layers, many different structural families have been investigated. This review surveys the structures and physical properties of all these oxychalcogenide materials and relates these properties to their common anti-cuprate square lattice [M2O] layer. It is organised around the different oxidation states of the metal ion M, in order to explore the effects of the electronic configuration of M on the physical properties of each compound as a whole. A key part of the review highlights the use of soft-chemical modifications to alter physical properties of these materials, in the synthesis of novel van der Waals materials and other metastable compounds. Future avenues for these materials in the bulk, few- and single-layer limits are discussed.
Materials Science (cond-mat.mtrl-sci)
25 pages, 11 figures. Accepted in Solid State Sciences
Nanoscale Strain Evolution and Grain Boundary-Mediated Defect Sink Behavior in Irradiated SiC: Insights from N-PED and DFT
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Nabil Daghbouj, Ahmed.T. AlMotasem, Jan. Duchoňb, Bingsheng. Li, Mohamed. Bensalem, Frans. Munnik, Xin Ou, Anna. Macková, William.J. Weber, Tomas. Polcara
Understanding irradiation-induced strain in silicon carbide (SiC) is essential for designing radiation-tolerant ceramic materials. However, conventional methods often fail to resolve nanoscale strain gradients, especially in polycrystalline forms. In this study, we employ nano-beam precession electron diffraction (N-PED) to perform high-resolution, multi-directional strain mapping in both single-crystal 4H-SiC and polycrystalline {\alpha}-SiC subjected to helium and hydrogen ion irradiation. The high-resolution X-ray diffraction (HR-XRD) simulations of He + H irradiated single-crystal 4H-SiC closely match the strain profiles obtained from N-PED, demonstrating the reliability and accuracy of the N-PED method. In He-irradiated polycrystalline {\alpha}-SiC at high temperatures, a bubble-depleted zone (BDZ) near the grain boundary (GB) reveals that GBs act as active sinks for irradiation-induced defects. N-PED further shows strain amplification localized at the GBs, reaching up to 2.5%, along with strain relief within the BDZ. To explain this behavior, density functional theory (DFT) calculations of binding and migration energies indicate a strong tendency for Si, C, and He atoms to segregate toward the GB core. This segregation reduces the availability of vacancies to accommodate He atoms and leads to local strain relaxation near the GB. Furthermore, first-principles tensile simulations reveal that Si and C interstitials mitigate He-induced GB embrittlement. Charge density and DOS analyses link this effect to the bonding characteristics between point defects and neighboring atoms at GB. These insights underscore the importance of grain boundary engineering in enhancing radiation tolerance of SiC for nuclear and space applications.
Materials Science (cond-mat.mtrl-sci)
12 figurs, 38 pages
Acta Materialia 2025
Ultrasound response to time-reversal symmetry breaking below the superconducting phase transition
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-24 20:00 EDT
Chris Halcrow, Paul Leask, Egor Babaev
Ultrasound attenuation is a powerful probe of symmetry-breaking phenomena in superconductors. In this work, we develop a framework to model the ultrasound response of multi-component superconductors undergoing a time-reversal symmetry breaking transition below the superconducting phase transition. By coupling the elastic strain of the crystal lattice to the superconducting order parameters through group-theoretical analysis of tetragonal crystals, we classify how different symmetry channels contribute to the ultrasound signal. Using a two-component Ginzburg–Landau theory, we analyze the temperature dependence of sound velocity across both superconducting and time-reversal symmetry breaking transitions for several cases, including $ (A_{1g}, A_{1g})$ , $ (A_{2g}, B_{1g})$ , and $ E_g$ representations. Our results demonstrate that ultrasound measurements are highly sensitive to the presence of bilinear Josephson couplings and can distinguish between different realizations of the superconducting state. We further show how external strain can significantly alter the ultrasound response in systems breaking time reversal symmetry.
Superconductivity (cond-mat.supr-con)
11 pages, 5 figures
Magnetic Ordering in Moiré Graphene Multilayers from a Continuum Hartree+U Approach
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Christopher T. S. Cheung, Valerio Vitale, Lennart Klebl, Ammon Fischer, Dante M. Kennes, Arash A. Mostofi, Johannes Lischner, Zachary A. H. Goodwin
Recently, symmetry-broken ground states, such as correlated insulating states, magnetic order and superconductivity, have been discovered in twisted bilayer graphene (tBLG) and twisted trilayer graphene (tTLG) near the so-called magic-angle. Understanding the magnetic order in these systems is challenging, as atomistic methods become extremely expensive near the magic angle and continuum approaches fail to capture important atomistic details. In this work, we develop a self-consistent approach based on a continuum model that incorporates both short-ranged Hubbard interactions and long-ranged Coulomb interactions, therefore allowing efficient exploration of magnetic order in moiré graphene multilayers. With this approach, we perform a systematic analysis of the magnetic phase diagram of tBLG as a function of doping level and twist angle, near the magic angle. We find that the results are consistent with previous perturbative atomistic Hartree+U calculations. Furthermore, we predict stable magnetic orders for the tTLG. We found that the magnetic orders are similar to those in tBLG for small values of on-site repulsion. In the future, the developed method can be utilized to investigate magnetic ordering tendencies from short-range exchange interactions in other moiré graphene multilayers as a function of doping, twist angle, screening environment, among other variables.
Materials Science (cond-mat.mtrl-sci)
Disorder-driven magnetic duality in the spin-$\frac{1}{2}$ system ktenasite, Cu$\text{2.7}$Zn$\text{2.3}$(SO$\text{4}$)$\text{2}$(OH)$\text{6}\cdot$6H$\text{2}$O
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Kaushick K. Parui, Anton A. Kulbakov, Roman Gumeniuk, Eduardo Carrillo-Aravena, María Teresa Fernández-Díaz, Stanislav Savvin, Artem Korshunov, Sergey Granovsky, Thomas Doert, Dmytro S. Inosov, Darren C. Peets
Disorder in frustrated quantum systems can critically influence their magnetic ground states and drive exotic correlated behavior. In the $ S = \frac{1}{2}$ system ktenasite, Cu$ _\text{2.7}$ Zn$ _\text{2.3}$ (SO$ _\text{4}$ )$ _\text{2}$ (OH)$ \text{6}\cdot$ 6H$ \text{2}$ O, we show that structural disorder drives an unexpected dimensional crossover and stabilizes a rare coexistence of distinct magnetic states. Neutron diffraction reveals significant Cu/Zn mixing at the Cu2 site, which tunes the Cu$ ^{2+}$ sublattice from a two-dimensional scalene-distorted triangular lattice into a one-dimensional spin-chain network. Magnetic susceptibility, neutron diffraction, ac susceptibility, and specific heat measurements collectively indicate magnetic duality: a coexistence of incommensurate long-range magnetic order below $ T\text{N} = 4,$ K and a cluster spin-glass state with $ T\text{f} = 3.28,$ K at $ \nu = 10,$ Hz. Our findings highlight ktenasite as a rare platform where structural disorder tunes the effective dimensionality and stabilizes coexisting ordered and glassy magnetic phases, offering a unique opportunity to explore the interplay of frustration, disorder, and dimensional crossover in quantum magnets.
Strongly Correlated Electrons (cond-mat.str-el)
15 pages, 13 figures. CIFs available as ancillary files
Size-dependent critical localization
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-09-24 20:00 EDT
Hui-Qiang Liang, Linhu Li, Guo-Fu Xu
Studying critical states in quasiperiodic systems is of great importance in localization physics. Previously identified critical states share a common characteristic: they exhibit persistent critical features in the thermodynamic limit. In this Letter, we predict an exotic type of critical state, termed size-dependent critical states, which exhibit a fundamentally distinct behavior. Specifically, they display critical localization signatures only at finite sizes, but transition to Anderson localization in the thermodynamic limit. We establish that the physical origin of size-dependent critical states lies in the synergistic interplay between local non-reciprocal domain wall and NHSE. By revealing a critical phase that challenges the established paradigm of critical localization, our work opens new avenues for exploring localization phenomena in quasiperiodic systems.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
4.5 pages, 5 figures in the main text; 4 pages, 3 figures in the Supplemental Material
A Methodological Study on Data Representation for Machine Learning Modelling of Thermal Conductivity of Rare-Earth Oxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Amiya Chowdhury, Acacio Rincón Romero, Eduardo Aguilar-Bejarano, Halar Memon, Grazziela Figueredo, Tanvir Hussain
Quantitative structure-activity relationship (QSAR) modelling is widely employed in materials sci- ence to predict properties of interest and extract useful descriptors for measured properties. In thermal barrier coatings (TBC), QSAR can significantly shorten the experimental discovery cycle, which can take years. Although machine learning methods are commonly employed for QSAR, their performance depends on the data quality and how instances are represented. Traditional, hand-crafted descriptors based on known material properties are limited to represent materials that share the same basic crystal structure, limited the size of the dataset. By contrast, graph neural networks offer a more expressive representation, encoding atomic positions and bonds in the crystal lattice. In this study, we compare Random Forest (RF) and Gaussian Process (GP) models trained on hand-crafted descriptors from the literature with graph-based representations for high-entropy, rare-earth pyrochlore oxides using the Crystal Graph Convolutional Neural Network (CGCNN). Two different types of augmentation methods are also explored to account for the limited data size, one of which is only applicable to graph-based representations. Our findings show that the CGCNN model substantially outperforms the RF and GP models, underscoring the potential of graph-based representations for enhanced QSAR modelling in TBC research.
Materials Science (cond-mat.mtrl-sci)
Intrinsic-perturbation induced anomalous higher-order boundary states in non-Hermitian systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-24 20:00 EDT
Hui-Qiang Liang, Zuxuan Ou, Linhu Li, Guo-Fu Xu
The behavior of higher-order boundary states in non-Hermitian systems is elusive and thereby finding the mechanism behind these states is both essential and significant. Here, we uncover a novel mechanism that induces anomalous higher-order boundary states. The mechanism originates from the sensitivity of the non-normal boundary Hamiltonian to intrinsic perturbations, where intrinsic perturbations here refer to the influence of the bulk on the topological boundaries. Based on the mechanism, we reveal a new kind of phase transition, i.e., the transition between hybrid skin-topological states and scale-free topological boundary states. We also find that scale-free topological boundary states exhibit size-dependent spectra, influencing the existence of higher-order topological boundary states. Unlike conventional hybrid skin-topological states or higher-order non-Hermitian skin effect, the above two kinds of anomalous higher-order boundary states exhibit size-dependent characteristics. Our work opens a new horizon for the control of higher-order boundary states and topological properties of non-Hermitian systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
4.7 pages, 3 figures in the main text; 16 pages, 10 figures in the Supplemental Material
Phys. Rev. B 111, L241112 (2025)
BatchTNMC: Efficient sampling of two-dimensional spin glasses using tensor network Monte Carlo
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-24 20:00 EDT
Tao Chen, Jingtong Zhang, Jing Liu, Youjin Deng, Pan Zhang
Efficient sampling of two-dimensional statistical physics systems remains a central challenge in computational statistical physics. Traditional Markov chain Monte Carlo (MCMC) methods, including cluster algorithms, provide only partial solutions, as their efficiency collapses for large systems in the presence of frustration and quenched disorder. The recently proposed Tensor Network Monte Carlo (TNMC) method offers a promising alternative, yet its original implementation suffers from inefficiencies due to the lack of scalable parallel sampling. In this work, we introduce BatchTNMC, a GPU-optimized and parallelized implementation of TNMC tailored for large-scale simulations of two-dimensional spin glasses. By leveraging batch processing and parallel sampling across multiple disorder realizations, our implementation achieves speedups of up to five orders of magnitude compared with the original serial scheme. Benchmarking on two-dimensional spin glasses demonstrates dramatic gains in efficiency: for instance, on a single GPU, BatchTNMC concurrently produces 1000 uncorrelated and unbiased samples across 1000 disorder realizations on $ 1024\times 1024$ lattices in just 3.3 hours, with an acceptance probability of 37%. These results establish BatchTNMC as a scalable and powerful computational framework for the study of two-dimensional disordered spin glass systems.
Statistical Mechanics (cond-mat.stat-mech)
10 pages, 4 figures
Contraction waves in pulsating active liquids: From pacemaker to aster dynamics
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-24 20:00 EDT
Tirthankar Banerjee, Thibault Desaleux, Jonas Ranft, Étienne Fodor
We propose a hydrodynamic theory to examine the emergence of contraction waves in dense active liquids composed of pulsating deformable particles. Our theory couples the liquid density with a chemical phase that determines the periodic deformation of the particles. This mechanochemical coupling regulates the interplay between the flow induced by local deformation, and the resistance to pulsation stemming from steric interaction. We show that this interplay leads the emergent contraction waves to spontaneously organize into a packing of pacemakers. We reveal that the dynamics of these pacemakers is governed by a complex feedback between slow and fast topological defects that form asters in velocity flows. In fact, our defect analysis is a versatile platform for investigating the self-organization of waves in a wide range of contractile systems. Our results shed light on the key mechanisms that control the rich phenomenology of pulsating liquids, with relevance for biological systems such as tissues made of confluent pulsating cells.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
8 pages, 4 figures
Angular momentum of vortex-core Majorana zero modes
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-24 20:00 EDT
Giulia Venditti, Christophe Berthod, Louk Rademaker
Majorana zero modes (MZMs) are highly sought-after states with a possible application in quantum computation. Here, we show that vortex-core MZMs can carry a nontrivial angular momentum. This establishes new `flavors’ of Majorana modes, independent of the Chern classification of topological superconductors. The MZM angular momentum is explicitly calculated for a microscopic model of a $ d+id$ superconductor placed on a three-dimensional topological insulator ($ d+id+\phantom{}$ Dirac model) using both exact diagonalization and the Chebyshev expansion. We classify all possible quantum numbers of MZMs depending on the windings of the order parameter and underlying normal state. The topological protection of the MZM is set by the bulk gap, quasiparticle poisoning by trivial in-gap states, and its localization length. All these severely limit the stability of MZMs in the $ d+id+\phantom{}$ Dirac model, in contrast to earlier claims. Nevertheless, the possibility of having different flavors of MZM - in the form of angular momentum or something else - can provide a unique path forward for the study of MZMs.
Superconductivity (cond-mat.supr-con)
15 pages, 9 figures
Layer controlled orbital selective Mott transition in monolayer nickelate
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Byungmin Sohn, Minjae Kim, Sangjae Lee, Wenzheng Wei, Juan Jiang, Fengmiao Li, Sergey Gorovikov, Marta Zonno, Tor Pedersen, Sergey Zhdanovich, Ying Liu, Huikai Cheng, Ke Zou, Yu He, Sohrab Ismail-Beigi, Frederick J. Walker, Charles H. Ahn
Dimensionality and electronic correlations are crucial elements of many quantum material properties. An example is the change of the electronic structure accompanied by the loss of quasiparticles when a metal is reduced from three dimensions to a lower dimension, where the Coulomb interaction between carriers becomes poorly screened. Here, using angle-resolved photoemission spectroscopy (ARPES), we report an orbital-selective decoherence of spectral density in the perovskite nickelate LaNiO3 towards the monolayer limit. The spectral weight of the dz2 band vanishes much faster than that of the dx2-y2 band as the thickness of the LaNiO3 layer is decreased to a single unit cell, indicating a stronger correlation effect for the former upon dimensional confinement. Dynamical mean-field theory (DMFT) calculations show an orbital-selective Mott transition largely due to the localization of dz2 electrons along the c axis in the monolayer limit. This orbital-selective correlation effect underpins many macroscopic properties of nickelates, such as metal-to-insulator transition and superconductivity, where most theories are built upon a dx2-y2-dz2 two-band model.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Anharmonicity-driven phonon avoided crossing and anomalous thermal transport in nodal-line semimetal ZrSiS
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Xin Jin, Qingqing Zhang, Dengfeng Li, Zhenxiang Cheng, Jianli Wang, Xuewei Lv, Xiaoyuan Zhou, Rui Wang, Xianyong Ding, Peng Yu, Xiaolong Yang
Understanding thermal and electrical transport in topological materials is essential for advancing their applications in quantum technologies and energy conversion. Herein, we employ first-principles calculations to systematically investigate phonon and charge transport in the prototypical nodal-line semimetal ZrSiS. The results unveil that anharmonic phonon renormalization results in the pronounced softening of heat-carrying phonons and suppressed lattice thermal conductivity ($ \kappa_{\rm L}$ ). Crucially, anharmonic effects are found to noticeably weaken Zr-S interactions, triggering avoided-crossing behavior of low-frequency optical phonons. The combination of phonon softening and avoided crossing synergistically reduces phonon group velocities, yielding a 16% suppression in $ \kappa_{\rm L}$ along the $ c$ -axis at room temperature. Contrary to conventional metals, we discover that the lattice contribution to thermal conductivity in ZrSiS is abnormally large, even dominating heat conduction along the $ c$ -axis. This unusual behavior results in a substantial deviation of the Lorenz number from the Sommerfeld value – exceeding it by up to threefold – thereby challenging the validation of standard Wiedemann-Franz law for thermal conductivity estimation. Moreover, our calculations demonstrate that ZrSiS exhibits exceptional electrical conductivity, attributed to its topological electronic Dirac states that accounts for both high Fermi velocities and weak electron-phonon coupling. This study provides critical insights into the electrical and thermal transport mechanisms in ZrSiS and highlights the importance of anharmonic effects in the lattice dynamics and thermal transport of metallic materials.
Materials Science (cond-mat.mtrl-sci)
12 pages,7 figures
Trends in the electronic structure of borophene polymorphs
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Alam Osorio, Lucia Reining, Francesco Sottile
Borophene is a two-dimensional material made out of boron atoms only. It exhibits polymorphism and different allotropes can be studied in terms of a rigid electronic structure, where only the occupation of the states change with the respect to the number of electrons available in the system (self-doping). In this work we selected a set of representative borophene polymorphs ($ \delta_3$ , $ \delta_5$ , $ \delta_6$ , $ \beta_{12}$ $ \alpha_1$ , $ \alpha’$ , $ \alpha’$ -Bilayer) and studied the shared features of their electronic structures and the limitations of this model. Our work revealed the appearance of defect-like states in some polymorphs when related to a parent rigid electronic structure, and bonding/antibonding monolayer-like states in the $ \alpha’$ -Bilayer. Moreover, we show how the buckling of $ \delta_6$ and $ \alpha’$ can act as a tuning parameter, enabling semimetallicity, Dirac cones, and nesting of the Fermi surface. In light of their promises for exotic but also useful behavior, we expect our work to foster the interest in larger and more complex borophene structures.
Materials Science (cond-mat.mtrl-sci)
First principles and scanning tunneling spectroscopical evidences for thermodynamically stable “on-top” sulfur divacancy in monolayer WS$_{2}$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Weiru Chen, John C. Thomas, Yihuang Xiong, Zhuohang Yu, Da Zhou, Shalini Kumari, Zhongwei Dai, Joshua A. Robinson, Mauricio Terrones, Archana Raja, Sinéad Griffin, Alexander Weber-Bargioni, Geoffroy Hautier
Chalcogen vacancies in monolayer transition metal dichalcogenides (TMDs), such as WS$ _{2}$ , play a crucial role in various applications ranging from optoelectronics and catalysis to quantum information science (QIS), making their identification and control essential. This study focuses on WS$ _{2}$ single vacancy and vacancy pairs. Using first principles computations, we investigate their thermodynamic stabilities and electronic structures. We identify an “on-top” divacancy configuration where two vacancies sit on top of each other to be the only energetically stable complex with a binding energy of 160 meV. We compute a small difference in electronic structure with a shift of the unoccupied state by 140 meV for the divacancy complex and observe electronic state shift during Scanning Tunneling Spectroscopy of a series of vacancy in WS$ _2$ providing spectroscopical evidence for the presence of this defect.
Materials Science (cond-mat.mtrl-sci)
Exploring Cation Selection and Disorder within Entropy-Driven $A_{6}B_{2}$O$_{17}$ ($A$=Zr/Hf, $B$=Nb/Ta) Oxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Jacob T. Sivak, R. Jackson Spurling, Jon-Paul Maria, Susan B. Sinnott
We investigate the local atomic and electronic structure, thermodynamic stability, and defect chemistry of $ A_{6}B_{2}$ O$ {17}$ ($ A$ = Zr/Hf, $ B$ = Nb/Ta) oxides using first-principles density functional theory (DFT) calculations. We examine both ordered unit cells as well as fully disordered special quasirandom structures to clearly discern the effects of cation disorder. Structural predictions align closely with previous experimental results and follow established ionic radii trends. The electronic structure is strongly dependent on $ B$ -cation species: $ A{6}$ Ta$ {2}$ O$ {17}$ compositions have ~30% larger band gaps than their $ A{6}$ Nb$ {2}$ O$ {17}$ counterparts. Defect chemistry is similar for all compositions, with anion vacancies being more energetically favorable than corresponding cation defects. All explored $ A{6}B{2}$ O$ {17}$ compositions are enthalpically unstable with respect to their $ A$ O$ {2}$ and $ B{2}$ O$ {5}$ competing oxides and are therefore classified as entropy-stabilized materials, supporting prior experimental results. The pronounced agreement between our disordered supercell predictions with experimental measurements indicates all explored $ A{6}B{2}$ O$ {17}$ compositions contain substantial cation disorder across all 6-, 7-, and 8-coordinated sites. Our findings collectively provide a fundamental understanding of the $ A{6}B{2}$ O$ _{17}$ material family through DFT calculations, establishing a framework for future compositional tuning to engineer targeted material properties.
Materials Science (cond-mat.mtrl-sci)
Re-emergent superconducting state with broken time-reversal symmetry under uniaxial stress
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-24 20:00 EDT
We study conditions of the appearance of $ U(1) \times \mathbb{Z}_2$ superconducting states that spontaneously break time-reversal symmetry (BTRS) on a square lattice as a function of applied stress. We focus on the spin-singlet s+id state. Calculations show that if critical temperatures coincide at zero stress they exhibit linear kink and no kink otherwise. We find that in general, the microscopic calculations show a complex phase diagram, for example, non-monotonic behavior of BTRS transition. Another beyond-Ginzburg-Landau theory result is that $ U(1)$ critical temperature can decrease under compressional strain for small Poisson ratio materials. In the second part of the paper we consider effects of boundaries and finiteness of the sample on the strain-induced splitting of $ T_c^{U(1)}$ and $ T_c^{\mathbb{Z}_2}$ transitions. A finite sample has BTRS boundary states with persistent superconducting currents over a wide range of band filling. Overall, the BTRS dome occupies a larger band filling–temperature phase space region for a mesoscopic sample with [110] surface compared to an infinite system. Hence, the presence of boundaries helps to stabilize the BTRS phase.
Superconductivity (cond-mat.supr-con)
14 pages, 13 figures
Thermoelectric quantum oscillations and Zeeman splitting in topological Dirac semimetal BaAl$_{4}$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
P. R. Mandal, Kefeng Wang, Tarapada Sarkar, Prathum Saraf, Danila Sokratov, Johnpierre Paglione
Three-dimensional topological semimetals hosting Dirac or Weyl fermions are a new kind of materials class in which conduction and valence bands cross each other. Such materials harbor a nontrivial Berry phase, which is an additional geometrical phase factor arising along the path of an adiabatic surface and can give rise to experimentally measurable quantities such as an anomalous Hall component. Here we report a systematic study of quantum oscillations of thermoelectric power in single crystals of the topological Dirac nodal-line semimetal BaAl$ _{4}$ . We show that the thermoelectric power (TEP) is a sensitive probe of the multiple oscillation frequencies in this material, with two of these frequencies shown to originate from the three-dimensional Dirac band. The detected Berry phase provides evidence of the angular dependence and non-trivial state under high magnetic fields. We also have probed the signatures of Zeeman splitting, from which we have extracted the Landé $ g$ -factor for this system, providing further insight into the non-trivial topology of this family of materials.
Strongly Correlated Electrons (cond-mat.str-el), Other Condensed Matter (cond-mat.other)
8 pages, 8 figures
Statistics and morphologies of stable droplets in scalar active fluids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-24 20:00 EDT
Kathrin Hertäg, Joshua F. Robinson, Thomas Speck
Conventional phase segregation is controlled by a positive interfacial tension, which implies that the system relaxes towards a state in which the interfacial area (or length) is minimized, typically manifesting as a single droplet that grows with the system size. Intriguingly, the extension of the underlying Model B paradigm by two non-potential terms (Active Model B+) is able to describe the stable coexistence of many finite droplets. Here we numerical study Active Model B+ in the vicinity of the transition between a single droplet (macrophase segregation) and multiple droplets (microphase segregation). Our results show that, although noise shifts transitions, the overall agreement with the mean-field theoretical predictions is very good. We find a strong correlation of droplet properties with a single parameter that determines the number, density, and the fractal dimension of droplets. Deeper inside the droplet phase we observe another transition to a hexagonal lattice of regular droplets.
Soft Condensed Matter (cond-mat.soft)
Optical probing of charge traps in organic field-effect transistors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
We report spatially resolved optical probing of charge traps in organic field-effect transistors using focussed laser illumination. By scanning a 635 nm laser across the transistor channel and simultaneously acquiring transfer characteristics, we observe persistent, localised shifts in transistor turn-on voltage correlated with illumination dose and position, with negligible impact on field-effect mobility. The effect is strongest 5-10 um from the source electrode and requires a drain-to-source scan direction with sub-10 um step size. Kelvin probe force microscopy confirms trapped negative charges along the scan path, consistent with exciton dissociation and electron trapping near the semiconductor-dielectric interface. The phenomenon is reproducible across multiple device geometries and organic semiconductors, including TMTES-pentacene, TIPS-pentacene, and diF-TES-ADT. These findings enable direct mapping of trap distributions and suggest new strategies for trap engineering, threshold voltage tuning, and development of organic optoelectronic memories.
Materials Science (cond-mat.mtrl-sci)
11 pages, 5 figures
Detachment limited interlayer transport processes during SrTiO3 pulsed laser epitaxy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Jeffrey G. Ulbrandt, Xiaozhi Zhang, Randall L. Headrick
Pulsed laser epitaxial growth is characterized by high instantaneous deposition rates that leads to the nucleation of transient islands, both on surface terraces, and on top of stable islands formed during previous deposition pulses. We report results from combined in-situ X-ray reflectivity and kinetic Monte Carlo (kMC) simulations. Specular reflectivity monitors interlayer transport, while diffuse scattering reveals the evolution of in-plane length scales, both during the recovery time between individual laser pulses and over multiple deposited layers. The initial stage after each laser pulse is faster than the temporal resolution of the experiment, while subsequent recovery occurs over seconds. The results suggest that transient islands on top of stable two-dimensional islands form immediately after the deposition pulse, and then ripen via detachment and diffusion, leading to the slower component. kMC simulations show that the detachment energy barrier plays a dominant role in determining the recovery time constant.
Materials Science (cond-mat.mtrl-sci)
24 pages, 9 figures
Orbital-Selective Band Structure Evolution in BaFe$_{2-x}$M$_x$As$_2$ (M = Cr, Co, Cu, Ru and Mn) Probed by Polarization-Dependent ARPES
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-24 20:00 EDT
K. R. Pakuszewski, M. R. Cantarino, I. Romanenko, A. P. Machado, M. M. Piva, G. S. Freitas, H. B. Pizzi, F. A. Garcia, P. G. Pagliuso, C. Adriano
We present a systematic study of the evolution of the band structure in the Fe-based superconductor family BaFe$ {2-x}$ M$ x$ As$ 2$ (M = Cr, Co, Cu, Ru and Mn) using polarization-dependent angle-resolved photoemission spectroscopy (ARPES). Low-substituted samples, with comparable spin-density wave transition temperatures ($ T\text{SDW}$ ), were chosen to facilitate controlled comparisons. The sizes of the central hole pockets ($ \alpha$ , $ \beta$ , and $ \gamma$ ) remain largely unchanged across different substitutions, showing no clear correlation with either $ T\text{SDW}$ or the As height relative to the Fe planes. However, subtle trends are observed: a modest increase in the size of the $ \eta\text{X}$ electron pocket correlates with the suppression of $ T_\text{SDW}$ . Furthermore, the contraction of the $ \eta_\text{X}$ pocket appears to be linked to an increase in the As height relative to the Fe planes. Our results suggest that the suppression of $ T_\text{SDW}$ is primarily driven by changes in the Fe-As bond length, with the effect being more pronounced in electronic states with planar character. These findings provide insight into the electronic structure of BaFe$ _{2-x}$ M$ _x$ As$ _2$ .
Superconductivity (cond-mat.supr-con)
First principles band structure of interacting phosphorus and boron/aluminum $δ$-doped layers in silicon
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Quinn T. Campbell, Andrew D. Baczewski, Shashank Misra, Evan M. Anderson
Silicon can be heavily doped with phosphorus in a single atomic layer (a $ \delta$ layer), significantly altering the electronic structure of the conduction bands within the material. Recent progress has also made it possible to further dope silicon with acceptor-based $ \delta$ layers using either boron or aluminum, making it feasible to create devices with interacting $ \delta$ layers with opposite polarity. It is not known, however, how these $ \delta$ layers will interact, particularly at small separation distances. Using Density Functional Theory, we calculate the electronic structure of a phosphorus-based $ \delta$ layer interacting with a boron or aluminum $ \delta$ layer, varying the distances between the $ \delta$ layers. At separations 10 Å and smaller, the dopant potentials overlap and largely cancel each other out, leading to an electronic structure closely mimicking bulk silicon. At separations greater than 10 Å, the two layers behave independently of one another, forming a p-n diode with an intrinsic layer taking the place of the depletion region. One mechanism for charge transfer between $ \delta$ layers at larger distances could be tunneling, where we see a greater than 3% probability for tunneling between a phosphorus and boron layer at 20 Å separation. This tunneling rate exceeds what would be seen for a standard silicon 1.1 eV triangular barrier, indicating that the interaction between delta layers creates enhanced tunneling at larger separation distances compared to a traditional junction. These calculations provide a foundation for the design of silicon-based electronics based on interacting $ \delta$ layers.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Atomistic mechanisms of oxidation and chlorine corrosion in Ni-based superalloys: The role of boron and light interstitial segregation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Tyler D. Doležal, Rodrigo Freitas, Ju Li
Hybrid Monte Carlo and molecular dynamics simulations were used to investigate the interaction of light interstitials in multi-element Ni-based alloys. We show that light interstitials such as boron and oxygen fundamentally alter interfacial chemistry by reshaping alloy-element distribution and segregation. Oxygen adsorption drove boron migration from the grain boundary to the free surface, where it co-enriched with Cr, Fe, and Mo and formed BO3 trigonal motifs embedded within mixed-metal oxide networks. Oxygen also promoted M-O-M chain formation, including Nb2O5 clusters at the free surface. In the absence of oxygen, boron segregated to the grain boundary, altering local metal chemistry and underscoring a dynamic, environment-sensitive behavior. Following chlorine exposure, the oxidized surfaces retained strong O-mediated connectivity while forming new Cl-M associations, particularly with Nb and Cr, and exhibited further surface enrichment in Cr, Fe, and Mo. High-temperature MD simulations revealed a dynamic tug-of-war: chlorine exerted upward pull and disrupted weakly anchored sites, while Nb- and BO3-rich oxide motifs resisted deformation. A new stabilization mechanism was identified in which subsurface boron atoms anchored overlying Cr centers, suppressing their mobility and mitigating chlorine-driven displacement. These results demonstrate boron’s dual role as a modifier of alloy-element segregation and a stabilizer of oxide networks, and identify Nb as a key element in reinforcing cohesion under halogen attack. More broadly, this study highlights the need to track light interstitial cross-talk and solute migration under reactive conditions, offering atomistic criteria for designing corrosion-resistant surface chemistries in Ni-based superalloys exposed to halogenated or oxidative environments.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Acta Materialia, 121556, September 2025
High temperature superconductivity with giant pressure effect in 3D networks of boron doped ultra-thin carbon nanotubes in the pores of ZSM-5 zeolite
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-24 20:00 EDT
Yibo Wang, Tsin Hei Koo, Runqing Huang, Yat Hei Ng, Timothée Tianyu Lortz, Ting Zhang, Wai Ming Chan, Yuxiao Hou, Jie Pan, Rolf Lortz, Ning Wan, Ping Sheng
We have fabricated three-dimensional (3D) networks of ultrathin carbon nanotubes (CNTs) within the ~5-Angstrom diameter pores of zeolite ZSM-5 crystals using the chemical vapour deposition (CVD) process. The 1D electronic characteristics of ultrathin CNTs are characterized by van Hove singularities in the density of states. Boron doping was strategically employed to tune the Fermi energy near a van Hove singularity, which is supported by extensive ab-initio calculations, while the 3D network structure ensures the formation of a phase-coherent bulk superconducting state under a 1D to 3D crossover. We report characteristic signatures of superconductivity using four complementary experimental methods: magnetization, specific heat, resistivity, and point-contact spectroscopy, all consistently support a critical temperature Tc at ambient conditions ranging from 220 to 250 K. In particular, point-contact spectroscopy revealed a multigap nature of superconductivity with a large ~30 meV leading gap, in rough agreement with the prediction of the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity. The differential conductance response displays a particle-hole symmetry and is tuneable between the tunnelling and Andreev limits via the transparency of the contact, as uniquely expected for a superconductor. Preliminary experiments also reveal a giant pressure effect which increases the Tc above the ambient temperature.
Superconductivity (cond-mat.supr-con)
Photo-Induced Enhancement of Critical Temperature in a Phase Competing Spin-Fermion System
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-24 20:00 EDT
Ultrafast optical excitation is known to destabilize long-range order in correlated systems, yet experiments have also reported the emergence of metastable phases, in some cases with enhanced critical temperatures. The microscopic origin of such light-induced stabilization remains unresolved. Here we investigate this problem within a minimal spin-fermion framework: a double-exchange model at half filling, augmented by ferromagnetic superexchange on a square lattice. In equilibrium, at half-filling the ordering temperature is set by the competition between kinetic-energy-driven antiferromagnetism and superexchange-induced ferromagnetism. Using quantum Landau-Lifshitz-Gilbert-Brown dynamics for localized spins combined with mean-field evolution of itinerant electrons, we demonstrate a nonthermal mechanism for stabilizing ordered phases. Photoexcitation creates a long-lived nonequilibrium carrier population that resists thermalization and reshapes the low-energy landscape, converting kinetic-energy-driven antiferromagnetism into ferromagnetism and enhancing the critical temperature. While model-specific, our results reveal a general microscopic pathway by which light can tip the balance between competing orders, suggesting routes toward optically engineered magnetism, charge-density-wave order, and superconductivity.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 6 figures
Extending Sample Persistence Variable Reduction for Constrained Combinatorial Optimization Problems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-24 20:00 EDT
Shunta Ide, Shuta Kikuchi, Shu Tanaka
Constrained combinatorial optimization problems (CCOPs) are challenging to solve due to the exponential growth of the solution space. When tackled with Ising machines, constraints are typically enforced by the penalty function method, whose coefficients must be carefully tuned to balance feasibility and objective quality. Variable-reduction techniques such as sample persistence variable reduction (SPVAR) can mitigate hardware limitations of Ising machines, yet their behavior on CCOPs remains insufficiently understood. Building on our prior proposal, we extend and comprehensively evaluate multi-penalty SPVAR (MP-SPVAR), which fixes variables using solution persistence aggregated across multiple penalty coefficients. Experiments on benchmark problems, including the quadratic assignment problem and the quadratic knapsack problem, demonstrate that MP-SPVAR attains higher feasible-solution ratios while matching or improving approximation ratios relative to the conventional SPVAR algorithm. An examination of low-energy states under small penalties clarifies when feasibility degrades and how encoding choices affect the trade-off between solution quality and feasibility. These results position MP-SPVAR as a practical variable-reduction strategy for CCOPs and lay a foundation for systematic penalty tuning, broader problem classes, and integration with quantum-inspired optimization hardware as well as quantum algorithms.
Statistical Mechanics (cond-mat.stat-mech)
16 pages, 13 figures
Molecular Insights into Caprock Integrity of Subsurface Hydrogen Storage: Perspective on Hydrogen-induced Swelling and Mechanical Response
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-24 20:00 EDT
Mehdi Ghasemi, Mohamad Ali Ghafari, Masoud Babaei, Valentina Erastova
The geological storage of hydrogen (H_2) requires reliable long-term caprock sealing, yet the nanoscale interactions between H_2 and clay minerals remain critically underexplored despite their importance for storage security. This lack of understanding has limited the ability to predict mechanical stability and leakage risks in H_2 storage formations. Using molecular simulations, this study investigates the swelling behavior and mechanical properties of sodium montmorillonite (Mt), a common smectite clay, under varying hydration states and interlayer H_2 contents. Results show that H_2 accelerates hydration-state transitions, narrows the stability window of crystalline swelling, and promotes asymmetric plume formation in confined interlayers. H_2 alters cation and water coordination, thereby weakening Na^+–Mt electrostatic interactions and modulating H-bond networks at the interface and in the bulk. Mechanical analysis reveals pronounced anisotropy in Mt. In-plane stiffness is mainly governed by basal spacing expansion, whereas out-of-plane stiffness is highly sensitive to the initial presence of water or H_2, which weaken interlayer cohesion. Tensile and compressive strengths in the in-plane directions follow in-plane stiffness trends, while the out-of-plane tensile strength is governed by Mt–water H-bonds. The presence of H_2 further promotes Mt sheets separation by disrupting nanoscale liquid bridges. Collectively, these results provide the first atomistic-scale evidence that intercalated H_2 reshapes swelling energetics, elastic anisotropy, and failure pathways in Mt, highlighting critical nanoscale mechanisms that may compromise caprock integrity during underground H_2 storage.
Materials Science (cond-mat.mtrl-sci)
Quantum oscillations between excitonic and quantum spin Hall insulators in moiré WSe2
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-24 20:00 EDT
Zhongdong Han, Yiyu Xia, Kenji Watanabe, Takashi Taniguchi, Kin Fai Mak, Jie Shan
Quantum spin Hall insulators (QSHIs) and excitonic insulators (EIs) are prototypical topological and correlated states of matter, respectively. The topological phase transition between the two has attracted much theoretical interest but experimental studies have been hindered by the availability of tunable materials that can access such a transition. Here, by utilizing the interaction-enhanced g-factor and the flat moiré bands in twisted bilayer WSe2 (tWSe2), we realize tunable electron-like and hole-like Landau levels (LLs) in the opposite valleys of tWSe2 under a perpendicular magnetic field. At half-band-filling, which corresponds to electron-hole charge neutrality, periodic oscillations between QSHIs (for fully filled LLs) and EIs (for half-filled LLs) are observed due to the interplay between the cyclotron energy and the intervalley correlation; QSHIs with up to four pairs of helical edge states can be resolved. We further analyze the effect of Fermi surface nesting on the stability of EIs via electric field-tuning of the moiré band structure. Our results demonstrate a novel QSHI-to-EI topological phase transition and provide a comprehensive understanding of the fermiology of tWSe2.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)