CMP Journal 2025-08-07
Statistics
Nature Physics: 2
Nature Reviews Physics: 1
Science: 11
Physical Review Letters: 17
Physical Review X: 1
arXiv: 61
Nature Physics
Fast optical control of a coherent hole spin in a microcavity
Original Paper | Magnetic properties and materials | 2025-08-06 20:00 EDT
Mark R. Hogg, Nadia O. Antoniadis, Malwina A. Marczak, Giang N. Nguyen, Timon L. Baltisberger, Alisa Javadi, Rüdiger Schott, Sascha R. Valentin, Andreas D. Wieck, Arne Ludwig, Richard J. Warburton
Many of the most promising quantum information platforms store quantum information in electronic or atomic spins. To incorporate these devices into quantum networks, a spin-photon interface is required. Currently, the best on-demand single-photon sources use a semiconductor quantum dot in an engineered photonic environment. However, it is difficult to achieve coherent spin control in a high-performance single-photon source, and spin coherence is limited by magnetic noise from nuclear spins in the semiconductor host material. Here we combine all-optical spin control with a quantum dot in an open microcavity. We demonstrate fast coherent rotations of a hole spin around an arbitrary axis of the Bloch sphere with a maximum π-pulse fidelity of 98.6%. To suppress the slow magnetic noise, we laser cool the nuclear spins using the hole as a central spin. This extends the hole spin free-induction-decay time by more than an order of magnitude. It becomes much larger than both rotation time and radiative recombination time of the spin, enabling the creation of many spin-photon pairs before the loss of spin coherence.
Magnetic properties and materials, Photonic devices, Quantum dots, Single photons and quantum effects
Frustrated electron hopping from the orbital configuration in a two-dimensional lattice
Original Paper | Electronic properties and materials | 2025-08-06 20:00 EDT
Aravind Devarakonda, Christie S. Koay, Daniel G. Chica, Morgan Thinel, Asish K. Kundu, Zhi Lin, Alexandru B. Georgescu, Sebastian Rossi, Sae Young Han, Michael E. Ziebel, Madisen A. Holbrook, Anil Rajapitamahuni, Elio Vescovo, Kenji Watanabe, Takashi Taniguchi, Milan Delor, Xiaoyang Zhu, Abhay N. Pasupathy, Raquel Queiroz, Cory R. Dean, Xavier Roy
Electron hopping on spatially periodic lattices gives rise to intriguing electronic behaviour. For example, hopping on the geometrically frustrated two-dimensional kagome, dice and Lieb lattices yields electronic band structures with both massless Dirac-like and perfectly dispersion-less, flat bands. As materials featuring the dice and Lieb lattice structures are scarce, an alternative approach proposes to leverage atomic orbitals to realize the characteristic electron hopping of geometrically frustrated lattices. This strategy promises to expand the list of candidate materials with frustrated electron hopping, but is yet to be shown in experiments. Here we demonstrate frustrated hopping in the van der Waals intermetallic Pd5AlI2, emerging from the arrangement of atomic orbitals in a primitive square lattice. Using angle-resolved photoemission spectroscopy and quantum oscillation measurements, we reveal that the band structure of Pd5AlI2 includes linear Dirac-like bands intersected at their crossing point by a locally flat band–an essential characteristic of frustrated hopping in Lieb and dice lattices. Moreover, this compound shows exceptional chemical stability, with its unusual bulk band structure and metallicity persisting in ambient conditions down to the monolayer limit. Hence, our results showcase a way to realize electronic structures characteristic of geometrically frustrated lattices in non-frustrated systems.
Electronic properties and materials, Two-dimensional materials
Nature Reviews Physics
Carbon-nanomaterial-enabled terahertz technology
Review Paper | Carbon nanotubes and fullerenes | 2025-08-06 20:00 EDT
Lijuan Xie, Carlos Criollo, Ruiyun Zhou, Mingming Zhang, Benhui Dai, Jacques Doumani, T. Elijah Kritzell, Jifan Yin, Wenhui Geng, Yibin Ying, Andrey Baydin, Junichiro Kono
Terahertz (THz) technology bridges the gap between electronics and photonics, unlocking transformative opportunities in medical diagnostics, molecular identification and next-generation wireless networks. Usually, THz devices have been made from conventional semiconductors and their heterostructures to achieve the necessary carrier transport properties and optical-to-THz conversion efficiencies. In the past decade, carbon nanomaterials, such as carbon nanotubes and graphene, have been successfully used in the development of THz devices, including emitters, detectors and modulators. These advances are enabled by the unique properties of these materials, including strong linear and nonlinear THz radiation absorption, ultrahigh carrier mobilities and facile gate tunability. In this Review, we present the latest advances in the generation, detection and modulation of THz radiation using carbon nanomaterials, particularly focusing on the use of carbon nanotubes and graphene. The challenges and opportunities of using carbon nanomaterials in THz technology and towards potential applications are discussed.
Carbon nanotubes and fullerenes, Graphene, Terahertz optics
Science
The membrane skeleton is constitutively remodeled in neurons by calcium signaling
Research Article | Cell biology | 2025-08-07 03:00 EDT
Evan Heller, Naina Kurup, Xiaowei Zhuang
The membrane skeleton in neurons adopts a periodic lattice structure in which actin filaments, capped by adducin and tropomodulin, form ring-shaped structures connected by spectrin tetramers along neurites. This membrane-associated periodic skeleton (MPS) is important for many neuronal functions. Using live-cell super-resolution imaging, we found that the MPS is surprisingly dynamic, undergoing local disassembly and reformation constitutively in axons. MPS remodeling is driven by calcium signaling, leading to actin-ring destabilization through protein kinase C-mediated adducin phosphorylation and to spectrin degradation by calpain. Formin, an actin-nucleating and -polymerizing enzyme, plays a dual role in MPS remodeling and maintenance. MPS remodeling is enhanced by neuronal activity and functionally facilitates endocytosis. Our results highlight the importance of a dynamic membrane skeletal structure in neuronal function.
Cysteinyl leukotrienes stimulate gut absorption of food allergens to promote anaphylaxis in mice
Research Article | Immunology | 2025-08-07 03:00 EDT
Laura R. Hoyt, Elise Liu, Eli C. Olson, Danielle R. Jacobsen, Emily R. Siniscalco, Rebecca A. Krier-Burris, Kara G. Greenfield, Caleb D. McBride, Mia M. Alfajaro, Julien A.R. Amat, Zhe Zhao, Lan Xu, Vivek Philip, Aditi Verma, Slim Fourati, Donna L. Senger, Lingdi Zhang, Supinda Bunyavanich, Sarah E. Glass, Robert J. Coffey, Craig B. Wilen, Adam Williams, Stephanie C. Eisenbarth
Food-specific immunoglobulin E (IgE) triggers life-threatening anaphylaxis; however, for unclear reasons, some people with food-specific IgE are asymptomatic upon allergen consumption. We studied strains of mice with different sensitivities to anaphylaxis when orally challenged with allergen to identify possible causes. In resistant C57BL/6 mice, intestinal goblet cells transported less food allergen than did anaphylaxis-susceptible strains, even before allergic sensitization. In a forward genetic screen, resistance was correlated with dipeptidase 1 (Dpep1) variants. DPEP1 is expressed in intestinal epithelium and catabolizes leukotriene D4 (LTD4). Blocking DPEP1 with cilastatin, deleting Dpep1, or administering LTD4 orally enhanced allergen transport in resistant mice. Conversely, pretreatment of susceptible mice with a synthesis inhibitor, zileuton, abrogated allergen absorption and oral anaphylaxis, indicating that this could be an approach to treating food allergy.
Intestinal mast cell-derived leukotrienes mediate the anaphylactic response to ingested antigens
Research Article | Immunology | 2025-08-07 03:00 EDT
Nathaniel D. Bachtel, Jaime L. Cullen, Min Liu, Steven A. Erickson, Vassily I. Kutyavin, Darine W. El-Naccache, Esther B. Florsheim, Jaechul Lim, Zuri A. Sullivan, Raiden Imaeda, Andrew Hudak, Cuiling Zhang, Ruslan Medzhitov
Anaphylaxis is a life-threatening complication of food allergen exposure. Although mechanisms governing anaphylaxis after intravenous injection are defined in mice, these models neglect mucosal exposure that accompanies ingestion. We investigated the role of mast cells within the intestine of mice and found that oral anaphylaxis required immunoglobulin E-Fcε receptor 1 (IgE-FcεR1) signaling. Intestinal mast cells were a heterogeneous population, shaped by epithelial cues. Compared with connective tissue mast cells found throughout the body, intestinal mast cells largely resided in the epithelium, displayed divergent transcriptomes and effector functions, and had a diminished ability to generate histamine, but they enhanced leukotriene synthesis. Mice genetically deficient in cysteinyl leukotriene synthesis, or those treated with the arachidonate 5-lipoxygenase (aLOX5) antagonist zileuton, were protected from oral antigen-induced responses, whereas those elicited by intravenous injection were unaltered.
An orthogonal T7 replisome for continuous hypermutation and accelerated evolution in E. coli
Research Article | Synthetic biology | 2025-08-07 03:00 EDT
Christian S. Diercks, Philipp Sondermann, Cynthia Rong, Thomas G. Gillis, Yahui Ban, Celine Wang, David A. Dik, Peter G. Schultz
Systems that perform continuous hypermutation of designated genes without compromising the integrity of the host genome can substantially accelerate the evolution of new or enhanced protein functions. We describe an orthogonal DNA replication system in Escherichia coli based on the controlled expression of the replisome of bacteriophage T7 (T7-ORACLE). The system replicates circular plasmids that enable high transformation efficiencies and seamless integration into standard molecular biology workflows. Engineering of T7 DNA polymerase yielded variant proteins with mutation rates of 1.7 × 10-5 substitutions per base in vivo–100,000-fold above the genomic mutation rate. We demonstrated continuous evolution using the T7 replisome by expanding the substrate scope of TEM-1 β-lactamase and increasing activity 5000-fold against clinically relevant monobactam and cephalosporin antibiotics in less than 1 week.
Transferrin receptor-targeted anti-amyloid antibody enhances brain delivery and mitigates ARIA
Research Article | Neuroscience | 2025-08-07 03:00 EDT
Michelle E. Pizzo, Edward D. Plowey, Nathalie Khoury, Wanda Kwan, Jordan Abettan, Sarah L. DeVos, Claire B. Discenza, Timothy Earr, David Joy, Ming Lye-Barthel, Elysia Roche, Darren Chan, Jason C. Dugas, Kapil Gadkar, Stefan Hamann, René Meisner, Jennifer Sebalusky, Ana Claudia Silva Amaral, Isabel Becerra, Roni Chau, Johann Chow, Allisa J. Clemens, Mark S. Dennis, Joseph Duque, Laura Fusaro, Jennifer A. Getz, Mihalis S. Kariolis, Do Jin Kim, Kendra J. Lechtenberg, Amy Wing-Sze Leung, Arash Moshkforoush, Hoang N. Nguyen, Emmanuel S. Ojo, Elliot R. Thomsen, Vanessa O. Torres, Pascal E. Sanchez, Lu Shan, Adam P. Silverman, Zachary K. Sweeney, Hilda Solanoy, Raymond Tong, Meredith E. Calvert, Ryan J. Watts, Robert G. Thorne, Paul H. Weinreb, Dominic M. Walsh, Joseph W. Lewcock, Thierry Bussiere, Y. Joy Yu Zuchero
Amyloid-related imaging abnormalities (ARIA), side effects of anti-amyloid drugs seen in magnetic resonance imaging of the brain, are a major safety concern in patients with Alzheimer’s disease. We developed an antibody transport vehicle (ATV) targeting transferrin receptor (TfR) for brain delivery of anti-amyloid-β protein (anti-Aβ) using asymmetrical Fc mutations (ATVcisLALA) that mitigates TfR-related liabilities and retains effector function when bound to Aβ. Administration of ATVcisLALA:Aβ in mice exhibited broad brain distribution and enhanced parenchymal plaque target engagement. This biodistribution reduced ARIA-like lesions and vascular inflammation. Taken together, ATVcisLALA has the potential to improve the next generation of Aβ immunotherapy through enhanced biodistribution mediated by transport across the blood-brain barrier.
Predicting expression-altering promoter mutations with deep learning
Research Article | Disease genomics | 2025-08-07 03:00 EDT
Kishore Jaganathan, Nicole Ersaro, Gherman Novakovsky, Yuchuan Wang, Terena James, Jeremy Schwartzentruber, Petko Fiziev, Irfahan Kassam, Fan Cao, Johann Hawe, Henry Cavanagh, Ashley Lim, Grace Png, Jeremy McRae, Abhimanyu Banerjee, Arvind Kumar, Jacob Ulirsch, Yan Zhang, Francois Aguet, Pierrick Wainschtein, Laksshman Sundaram, Adriana Salcedo, Sofia Kyriazopoulou Panagiotopoulou, Delasa Aghamirzaie, Evin Padhi, Ziming Weng, Shan Dong, Damian Smedley, Mark Caulfield, Anne O’Donnell-Luria, Heidi L. Rehm, Stephan J. Sanders, Anshul Kundaje, Stephen B. Montgomery, Mark T. Ross, Kyle Kai-How Farh
Only a minority of patients with rare genetic diseases are presently diagnosed by exome sequencing, suggesting that additional unrecognized pathogenic variants may reside in noncoding sequence. In this work, we describe PromoterAI, a deep neural network that accurately identifies noncoding promoter variants that dysregulate gene expression. We show that promoter variants with predicted expression-altering consequences produce outlier expression at both the RNA and protein levels in thousands of individuals and that these variants experience strong negative selection in human populations. We observed that clinically relevant genes in patients with rare diseases are enriched for such variants and validated their functional impact through reporter assays. Our estimates suggest that promoter variation accounts for 6% of the genetic burden associated with rare diseases.
Strain-coupled, crystalline polymer-inorganic interfaces for efficient magnetoelectric sensing
Research Article | Magnetic sensing | 2025-08-07 03:00 EDT
Binbin He, Yuanyuan He, Wenhui Wang, Yingzhi Sun, Shengwen Kong, Jin Huang, Yunfei Ru, Bingchao Qin, Huili Ren, Jing He, Tianyi Zhao, Jing Li, Jiong Lu, Li-Dong Zhao, Mingjie Liu
Magnetoelectric sensing holds promise for flexible sensors, offering precise detection of both electric and magnetic fields with minimal power consumption. However, its practical use has been constrained by weak magnetoelectric effects and limited overall performance, particularly under mechanical strain. Herein, we fabricated robust magnetoelectric polymer-inorganic nanocomposites through an interfacial cocrystallization strategy. By leveraging diazonium chemistry on vanadium diselenide (VSe2) monolayers, we created a submolecular-flat interface between ferromagnetic VSe2 and ferroelectric poly(vinylidene fluoride) (PVDF) nanocrystals. This highly crystalline interface has few mobile polymer chains and thus limits energy dissipation and enhances interfacial energy transfer. The scalable composite films show exceptional magnetoelectric performance, with a magnetocapacitive coefficient of 23.6%. These films enable ultrafast magnetoelectric detection, approaching a 10-fold increase in speed compared with conventional sensors, and offer opportunities for integrating multifunctional materials such as thermoelectric coolers into wearable devices.
Radular teeth matrix protein 1 directs iron oxide deposition in chiton teeth
Research Article | Biominerals | 2025-08-07 03:00 EDT
Michiko Nemoto, Koki Okada, Haruka Akamine, Yuki Odagaki, Yuka Narahara, Kenji Okoshi, Kiori Obuse, David Kisailus, Hisao Moriya, Akira Satoh
Nature builds multiscale mineral structures with impressive mechanical properties through spatially and temporally orchestrated organic-mineral assembly. One example of regulated mineralization is found in hypermineralized and ultrahard magnetic teeth of chiton, which grind on rock to feed on algae. At early stages of tooth formation, iron oxide deposition is controlled using a chiton-specific radular teeth matrix protein 1 (RTMP1), which is transported into teeth through microvilli. RTMP1 spatially and temporally guides and enhances mineralization on chitinous fibers within the tooth, providing a hard, tough, and strong architecture that enables the organism to perform repetitive abrasive events to survive.
Imaging collective quantum fluctuations of the structure of a complex molecule
Research Article | Chemical physics | 2025-08-07 03:00 EDT
Benoît Richard, Rebecca Boll, Sourav Banerjee, Julia M. Schäfer, Zoltan Jurek, Gregor Kastirke, Kilian Fehre, Markus S. Schöffler, Nils Anders, Thomas M. Baumann, Sebastian Eckart, Benjamin Erk, Alberto De Fanis, Reinhard Dörner, Sven Grundmann, Patrik Grychtol, Max Hofmann, Markus Ilchen, Max Kircher, Katharina Kubicek, Maksim Kunitski, Xiang Li, Tommaso Mazza, Severin Meister, Niklas Melzer, Jacobo Montano, Valerija Music, Yevheniy Ovcharenko, Christopher Passow, Andreas Pier, Nils Rennhack, Jonas Rist, Daniel E. Rivas, Daniel Rolles, Ilme Schlichting, Lothar Ph. H. Schmidt, Philipp Schmidt, Daniel Trabert, Florian Trinter, Rene Wagner, Peter Walter, Pawel Ziolkowski, Artem Rudenko, Michael Meyer, Robin Santra, Ludger Inhester, Till Jahnke
Because of the Heisenberg uncertainty principle, the structure of a molecule fluctuates about its mean geometry, even in the ground state. Observing this fundamental quantum effect experimentally–particularly, revealing the collective nature of the structural quantum fluctuations–remains an unmet challenge for complex molecules. In this work, we achieved this for an 11-atom molecule by inducing its Coulomb explosion with an x-ray free-electron laser. We show that the structural fluctuations manifest themselves in correlated variations of ion momenta obtained through coincident detection of the atomic fragments from individual molecules. Our analysis scheme allows extracting these variations, despite our measurements covering only a fraction of the full 33-dimensional momentum space, thereby establishing a general approach for extracting information on high-dimensional structural dynamics using Coulomb explosion.
Single-photon detection enabled by negative differential conductivity in moiré superlattices
Research Article | Optoelectronics | 2025-08-07 03:00 EDT
Krystian Nowakowski, Hitesh Agarwal, Sergey Slizovskiy, Robin Smeyers, Xueqiao Wang, Zhiren Zheng, Julien Barrier, David Barcons Ruiz, Geng Li, Riccardo Bertini, Matteo Ceccanti, Iacopo Torre, Bert Jorissen, Antoine Reserbat-Plantey, Kenji Watanabe, Takashi Taniguchi, Lucian Covaci, Milorad V. Milošević, Vladimir Fal’ko, Pablo Jarillo-Herrero, Roshan Krishna Kumar, Frank H. L. Koppens
Detecting individual light quanta is essential for quantum information, space exploration, advanced machine vision, and fundamental science. In this work, we introduce a single-photon detection mechanism using highly photosensitive nonequilibrium electron phases in moiré materials. Using tunable bands in bilayer graphene/hexagonal boron nitride superlattices, we engineer negative differential conductance and a sensitive bistable state capable of detecting single photons. Operating in this regime, we demonstrate single-photon counting at mid-infrared (11.3 micrometers) and visible wavelengths (675 nanometers) and temperatures up to 25 kelvin. This detector offers prospects for broadband, high-temperature quantum technologies with complementary metal-oxide semiconductor compatibility and seamless integration into photonic-integrated circuits. Our analysis suggests that the underlying mechanism originates from superlattice-induced negative differential velocity.
Three-dimensional nucleation and growth of deformation twins in magnesium
Research Article | Metallurgy | 2025-08-07 03:00 EDT
Sangwon Lee, Michael Pilipchuk, Can Yildirim, Duncan Greeley, Qianying Shi, Tracy D. Berman, Adam Creuziger, Evan Rust, Carsten Detlefs, Veera Sundararaghavan, John E. Allison, Ashley Bucsek
At two-thirds the weight of aluminum, magnesium alloys have the potential to reduce the fuel consumption of transportation vehicles. These advancements depend on our ability to optimize the desirable versus undesirable effects of deformation twins, which are three-dimensional (3D) microstructural domains that form under mechanical stresses. Previously only characterized through surface or thin-film measurements, we present 3D in situ characterization of deformation twinning inside an embedded grain over mesoscopic fields of view using dark-field x-ray microscopy supported by crystal plasticity finite element analysis. The results revealed the role of triple junctions on twin nucleation and the sequence and irregularity of twin growth and showed that twin-grain junctions, twin-twin junctions, and twin boundaries were the sites of localized dislocation accumulation.
Physical Review Letters
Necessary and Sufficient Condition for Randomness Certification from Incompatibility
Research article | Nonlocality | 2025-08-06 06:00 EDT
Yi Li, Yu Xiang, Jordi Tura, and Qiongyi He
Quantum randomness can be certified from probabilistic behavior demonstrating Bell nonlocality or Einstein-Podolsky-Rosen steering, leveraging outcomes from uncharacterized devices. However, in standard spot-checking protocols, such nonlocal correlations are not always sufficient for this task, necessitating the identification of required minimum quantum resources. In this Letter, we focus on the bipartite scenario and provide the necessary and sufficient condition for nonzero certified randomness under any arbitrary but fixed input, formulated in terms of measurement incompatibility. Further, we develop practical approaches to detect it. Firstly, we show that the steering-based randomness can be certified if and only if the correlations arise from a measurement compatibility structure that is not isomorphic to a hypergraph containing a star subgraph. In such a structure, the central measurement is individually compatible with the measurements at branch sites, ruling out the possibility of certified randomness in the central measurement outcomes. Subsequently, we generalize this result to the Bell scenario, proving that the violation of any chained Bell inequality involving a finite number of inputs and outputs excludes such a compatibility structure, thereby validating all chained inequalities as credible witnesses for randomness certification. Our results point out the role of an incompatibility structure in generating random numbers, offering a way to identify minimum quantum resources for the task.
Phys. Rev. Lett. 135, 060201 (2025)
Nonlocality, Quantum correlations in quantum information, Quantum cryptography, Quantum information processing
Stabilizer Scars
Research article | Eigenstate thermalization | 2025-08-06 06:00 EDT
Jeremy Hartse, Lukasz Fidkowski, and Niklas Mueller
Quantum many-body scars are eigenstates in nonintegrable isolated quantum systems that defy typical thermalization paradigms, violating the eigenstate thermalization hypothesis and quantum ergodicity. We identify exact analytic scar solutions in a $2+1$ dimensional lattice gauge theory in a quasi-1D limit as zero-magic resource stabilizer states. Our results also highlight the importance of magic resources for gauge theory thermalization, revealing a connection between computational complexity and quantum ergodicity.
Phys. Rev. Lett. 135, 060402 (2025)
Eigenstate thermalization, Lattice gauge theory, Quantum scars, Quantum many-body systems
Optimal Bound on Long-Range Distillable Entanglement
Research article | Quantum entanglement | 2025-08-06 06:00 EDT
Jonah Kudler-Flam, Vladimir Narovlansky, and Nikita Sopenko
We prove an upper bound on long-range distillable entanglement in $D$ spatial dimensions. Namely, it must decay faster than $1/r$, where $r$ is the distance between entangled regions. For states that are asymptotically rotationally invariant, the bound is strengthened to $1/{r}^{D}$. We then find explicit examples of quantum states with decay arbitrarily close to the bound. In one dimension, we construct free fermion Hamiltonians with nearest neighbor couplings that have these states as ground states. Curiously, states in conformal field theory are far from saturation, with distillable entanglement decaying faster than any polynomial.
Phys. Rev. Lett. 135, 060403 (2025)
Quantum entanglement, Quantum information theory, Disordered systems, Quantum many-body systems, Conformal field theory
Quantum Enhancement of Thermalization
Research article | Cold gases in optical lattices | 2025-08-06 06:00 EDT
Yulong Qiao, Frank Großmann, Peter Schlagheck, and Gabriel M. Lando
Equilibrium properties of many-body systems with a large number of degrees of freedom are generally expected to be described by statistical mechanics. Such expectations are closely tied to the observation of thermalization, as manifested through equipartition in time-dependent observables, which takes place both in quantum and classical systems but may look very different in comparison. By studying the dynamics of individual lattice site populations in ultracold bosonic gases, we show that the process of relaxation toward equilibrium in a quantum system can be orders of magnitude faster than in its classical counterpart. Classical chaos quantifiers reveal that this is due to a wave packet in a quantum system being able to escape regions of inefficient classical transport by a mechanism akin to tunneling. Since the presented phenomenon takes place in a broad parameter range and persists in weakly disordered systems, we expect that it occurs in a variety of many-body systems and is amenable to direct experimental verification in state-of-the-art quantum simulation platforms.
Phys. Rev. Lett. 135, 060404 (2025)
Cold gases in optical lattices, Quantum statistical mechanics, Quantum many-body systems
Longitudinal and Nonlinear Coupling for High-Fidelity Readout of a Superconducting Qubit
Research article | Quantum control | 2025-08-06 06:00 EDT
Can Wang, Feng-Ming Liu, He Chen, Yi-Fei Du, Chong Ying, Jian-Wen Wang, Yong-Heng Huo, Cheng-Zhi Peng, Xiaobo Zhu, Ming-Cheng Chen, Chao-Yang Lu, and Jian-Wei Pan
Despite the significant progress in superconducting quantum computation over the past years, quantum state measurement still lags nearly an order of magnitude behind quantum gate operations in speed and fidelity. The main challenge is that the strong coupling and readout signal used to probe the quantum state may also introduce additional channels which may cause qubit state transitions. Here, we design a novel architecture to implement the long-sought longitudinal interaction scheme between qubits and resonators. This architecture not only provides genuine longitudinal interaction by eliminating residual transversal couplings, but also introduces proper nonlinearity to the resonator that can further minimize decay error and measurement-induced excitation error. Combined with the multilevel readout protocol, we achieved a measurement fidelity of 99.8% in 202 ns without requiring any first-stage amplification. This highlights its potential as a highly promising architecture for superconducting qubit measurement.
Phys. Rev. Lett. 135, 060803 (2025)
Quantum control
Complete Gravitational-Wave Spectrum of the Sun
Research article | Gravitational waves | 2025-08-06 06:00 EDT
Camilo García-Cely and Andreas Ringwald
The high-temperature plasma in the solar interior generates stochastic gravitational waves (GWs). Owing to its significance as the primary source of high-frequency GWs in the Solar System, we reexamine this phenomenon by highlighting some physical processes, including the contribution of macroscopic hydrodynamic fluctuations. Our analysis builds upon several studies of axion emission from the Sun, particularly in relation to the treatment of plasma effects. The resulting GW spectrum is comparable to many well-motivated early-Universe signals, yet orders of magnitude below the current sensitivities of axion helioscopes such as (Baby)IAXO.
Phys. Rev. Lett. 135, 061001 (2025)
Gravitational waves, Particle dark matter, Axions, Sun
Spectral Constraints on Theories of Colored Particles and Gravity
Effective field theory | 2025-08-06 06:00 EDT
Aaron Hillman, Yu-tin Huang, Laurentiu Rodina, and Justinas Rumbutis
In this Letter, we consider effective field theories for light fields transforming under the fundamental or adjoint representation of a continuous group. Assuming tree-level completions, we demonstrate that, in the presence of gravity, crossing symmetry combined with twice-subtracted sum rules leads to constraints on the irreducible representations that the ultraviolet degrees of freedom must populate. A spectrum is allowed only if its low energy projection contains the graviton pole. Beautifully, the graviton pole is the anchor of our argument, not an obstruction.
Phys. Rev. Lett. 135, 061604 (2025)
Effective field theory, Quantum gravity, Scattering amplitudes, Symmetries
Observation of Kibble-Zurek Behavior across Topological Transitions of a Chern Band in Ultracold Atoms
Research article | Bose gases | 2025-08-06 06:00 EDT
Huan Yuan, Chang-Rui Yi, Jia-Yu Guo, Xiang-Can Cheng, Rui-Heng Jiao, Jinyi Zhang, Shuai Chen, and Jian-Wei Pan
The Kibble-Zurek (KZ) mechanism renders a theoretical framework for elucidating the formation of topological defects across continuous phase transitions. Nevertheless, it is not immediately clear whether the KZ mechanism applies to topological phase transitions. The direct experimental study for such a topic is hindered by quenching a certain parameter over orders of magnitude in topological materials. Instead, we investigate the KZ behavior across topological transitions of a Chern band in two-dimensional (2D) optical Raman lattices with quantum gases. Defined as the defects, excitation density is reconstructed via measuring the spin wave functions, with which the power-law scaling of total excitation density is extracted and such scaling could be interpreted within the KZ framework. Our work has heralded the commencement of experimentally exploring the KZ mechanism of the topological phase transitions.
Phys. Rev. Lett. 135, 063403 (2025)
Bose gases, Dynamical phase transitions, Spin-orbit coupling, Topological phase transition, Trapped atoms, Ultracold gases, Optical lattices & traps
Quantum Synchronization of Twin Limit-Cycle Oscillators
Research article | Open quantum systems | 2025-08-06 06:00 EDT
Tobias Kehrer, Christoph Bruder, and Parvinder Solanki
Quantum synchronization has been a subject of intensive research in the last decade. In this Letter, we propose a quantum Li'enard system whose classical equivalent features two limit cycles to one of which the system will converge. In the quantum case, both limit cycles coexist in a single steady state. Each of these limit cycles localizes to a distinct phase if coupled to an external drive: one quantum state can thus be assigned two phases. Furthermore, coupling two such oscillators leads to the simultaneous appearance of synchronization and a synchronization blockade. To shed light on this apparent paradoxical result, we introduce finer measures of quantum synchronization.
Phys. Rev. Lett. 135, 063601 (2025)
Open quantum systems, Quantum optics, Synchronization, Coupled oscillators
Photonic Torons with 3D Topology Transitions and Tunable Spin Monopoles
Research article | Angular momentum of light | 2025-08-06 06:00 EDT
Haijun Wu, Nilo Mata-Cervera, Haiwen Wang, Zhihan Zhu, Chengwei Qiu, and Yijie Shen
Topological defects and textures play crucial roles in fundamental physics and modern information science. Torons are a class of three-dimensional (3D) chiral topological structures with both skyrmionic quasiparticle textures and monopole point defects, so far only observed in liquid crystals with both polar and nonpolar symmetry. Here, we construct torons with the photonic spin of vector structured light and demonstrate the topological phase transitions among diverse 3D topological states: torons, hopfions, skyrmioniums and monopole pairs. We can also continually tune the toron’s chirality and monopole’s helicity. The generation of photonic torons opens a platform for studying nontrivial light-matter interaction and topological informatics.
Phys. Rev. Lett. 135, 063802 (2025)
Angular momentum of light, Classical optics, Photonics, Structured light, Monopoles, Skyrmions, Topology
Phase-Biased Andreev Diffraction Grating
Research article | Andreev reflection | 2025-08-06 06:00 EDT
Magnus R. Lykkegaard, Anders Enevold Dahl, Tyler Lindemann, Michael J. Manfra, Karsten Flensberg, and Charles M. Marcus
In optical diffraction, the phase difference between sources in a grating or multislit mask is determined by the angle to the imaging screen, yielding the familiar multilobed diffraction image. Here, we realize a similar phenomenon in a superconductor-semiconductor hybrid circuit configured to allow Andreev scattering from multiple parallel scatterers. Phase differences between scatterers are set by tapping off of a remote superconducting meander. We investigate arrays with two, three, four, and ten Andreev scatterers, examining local and nonlocal diffraction patterns, finding good agreement with a theory of multiple Andreev scattering, not to be confused with multiple Andreev reflection. Adding current-carrying taps to the meander allows individual phase control.
Phys. Rev. Lett. 135, 066301 (2025)
Andreev reflection, Heterostructures, Josephson junctions
Mapping Delocalization of Impurity Bands across Archetypal Mott-Anderson Transition
Research article | Critical phenomena | 2025-08-06 06:00 EDT
M. Parzer, F. Garmroudi, A. Riss, T. Mori, A. Pustogow, and E. Bauer
Tailoring charge transport in solids on demand is the overarching goal of condensed-matter research as it is crucial for electronic applications. Yet, often the proper tuning knob is missing and extrinsic factors such as impurities and disorder impede coherent conduction. Here, we control the very buildup of an electronic band from impurity states within the pseudogap of ternary ${\mathrm{Fe}}{2\text{- }\mathrm{x}}{\mathrm{V}}{1+x}\mathrm{Al}$ Heusler compounds via reducing the Fe content. Our density-functional theory calculations combined with specific heat and electrical resistivity experiments reveal that, initially, these states are Anderson-localized at low V concentrations $0<x<0.1$. As $x$ increases, we monitor the formation of mobility edges upon the archetypal Mott-Anderson transition and map the increasing bandwidth of conducting states by thermoelectric measurements. Ultimately, delocalization of charge carriers in fully disordered ${\mathrm{V}}_{3}\mathrm{Al}$ results in a resistivity exactly at the Mott-Ioffe-Regel limit that is perfectly temperature-independent up to 700 K—more constant than constantan.
Phys. Rev. Lett. 135, 066302 (2025)
Critical phenomena, Doping effects, Metal-insulator transition, Disordered systems, Heusler alloy, Thermoelectrics, Resistivity measurements
Creating Currents of Electric Skyrmion Bubbles
Research article | Ferroelectric domains | 2025-08-06 06:00 EDT
Jorge Íñiguez-González and Hugo Aramberri
The experimental demonstration of electric skyrmion bubbles and the recent prediction of their Brownian motion have brought topological ferroelectrics close to their magnetic counterparts. Electric bubbles (e-bubbles) could potentially be leveraged in applications for which magnetic skyrmions have been proposed (e.g., neuromorphic computing). Yet, we still lack a strategy to create currents of e-bubbles. Here, using predictive atomistic simulations, we illustrate two approaches to induce e-bubble currents by application of suitable electric fields, static or dynamic. We focus on regimes where e-bubbles display spontaneous diffusion, which allows us to generate a current by simply biasing their Brownian motion. Our calculations indicate that e-bubble velocities over $25\text{ }\text{ }\mathrm{m}/\mathrm{s}$ can be achieved at room temperature, suggesting that these electric quasiparticles could rival the speeds of magnetic skyrmions upon further optimization.
Phys. Rev. Lett. 135, 066601 (2025)
Ferroelectric domains, Lattice dynamics, Quasiparticles & collective excitations, Brownian dynamics
Time-Varying Strong Coupling and the Induced Time Diffraction of Magnon Modes
Research article | Magnetization dynamics | 2025-08-06 06:00 EDT
Jinwei Rao, Yi-Pu Wang, Zhijian Chen, Bimu Yao, Kaixin Zhao, Chunke Wei, Congyi Wang, Runze Li, Lihui Bai, and Wei Lu
By rapidly modulating strong magnon-magnon coupling with microwave pulses, researchers create “time slits” that generate double-slit magnon diffraction–analogous to Young’s double-slit experiment of light.
Phys. Rev. Lett. 135, 066704 (2025)
Magnetization dynamics, Magnons, Spintronics, Magnetic insulators, Ferromagnetic resonance, Microwave techniques
Observation of Coherent Perfect Acoustic Absorption at an Exceptional Point
Research article | Acoustic metamaterials | 2025-08-06 06:00 EDT
Yi-Fei Xia, Zi-Xiang Xu, Yu-Ting Yan, An Chen, Jing Yang, Bin Liang, Jian-Chun Cheng, and Johan Christensen
Non-Hermitian systems have recently shown new possibilities to manipulate wave scattering by exploiting loss, yet coherent perfect absorption at an exceptional point (CPA EP) remains elusive in acoustics. Here, we demonstrate it based on a two-channel waveguide with compact lossy resonators. We realize imbalanced losses crucial for CPA EP by using active components to independently modulate the non-Hermiticity. The CPA EP experimentally manifests as full absorption at a unique real frequency and shows high sensitivity to the incident phase variations. Our findings open an avenue to explore novel non-Hermitian physics for classical waves and develop innovative acoustic singularity-based devices.
Phys. Rev. Lett. 135, 067001 (2025)
Acoustic metamaterials, Exceptional points, Non-Hermitian systems
Heat Diffusion Invariant
Research article | Fourier’s law | 2025-08-06 06:00 EDT
Liujun Xu, Pengfei Zhuang, Fubao Yang, Shuihua Yang, Chengmeng Wang, Gaole Dai, Jiping Huang, and Cheng-Wei Qiu
Topological invariants have been utilized profoundly to classify the geometric features of electronic, photonic, and phononic structures. However, no invariant has ever been conceptualized to classify the functional properties of diverse thermal structures. Here, we formulate a heat diffusion invariant to reveal the explicit correlation between thermal functionality and diffusivity. The value goes beyond establishing a unified framework for various thermal metamaterials. The heat diffusion invariant offers a forward paradigm for precisely achieving freeform transient thermal metamaterials with isotropic thermal conductivity. We verify the competitiveness and robustness experimentally via a freeform transient thermal cloak. The heat diffusion invariant also paves the way for other functions, such as transient thermal illusion, and applies to thermal convection and radiation. These findings could open up an unprecedented invariant-based gateway to thermal management, metamaterial design, and nonequilibrium energy and mass transport.
Phys. Rev. Lett. 135, 067103 (2025)
Fourier’s law, Heat transfer, Metamaterials
Inferring the Isotropic-Nematic Phase Transition with Generative Machine Learning
Research article | Critical exponents | 2025-08-06 06:00 EDT
Eric R. Beyerle and Pratyush Tiwary
Generative machine learning models are capable of learning the phase behavior in condensed matter systems such as the Ising model. We utilize a score-based modeling procedure called thermodynamic maps to describe the isotropic-nematic phase transition in a melt of Gay-Berne ellipsoids. When trained on samples from a single temperature on either side of the phase transition, this generative machine learning approach infers effectively the nematic order parameter at intermediate temperatures. These results demonstrate score-based models’ ability to learn the physics of a nontrivial liquid crystal phase transition.
Phys. Rev. Lett. 135, 068102 (2025)
Critical exponents, Critical phenomena, Nematic order, Nematic liquid crystals, Machine learning
Physical Review X
Bipartite Fluctuations of Critical Fermi Surfaces
Research article | Critical phenomena | 2025-08-06 06:00 EDT
Xiao-Chuan Wu
Shape-dependent charge fluctuations in metals reveal a universal “corner term” that serves as a fingerprint for a class of unconventional quantum phase transitions driven by strong electron interactions.
Phys. Rev. X 15, 031035 (2025)
Critical phenomena, Fermi surface, Fractionalization, 2-dimensional systems
arXiv
MHD Macroscopic ball analysis: An Open Toolkit for Analyzing Magnetic Particle Rotation in Viscous Media
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
This paper presents MHD_Macroscopic_ball_analysis, an open-source Python toolkit developed to study the rotational dynamics of magnetized spherical particles immersed in viscous media under externally applied rotating magnetic fields. The toolkit extracts the orientation of the magnetic moment from grayscale video frames using image processing and enables detailed comparisons with synchronized magnetic field vector data. We outline the motivation, core algorithms, implementation, and validation of the toolkit in the context of macroscopic experiments simulating magnetohydrodynamic (MHD) particle behavior. The full source code and documentation are freely available on GitHub at this https URL, with a citable version archived on Zenodo at this https URL.
Soft Condensed Matter (cond-mat.soft)
Topological domain-wall states from Umklapp scattering in twisted bilayer graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
Juncheng Li, Cong Chen, Wang Yao
Twistronics, harnessing interlayer rotation to tailor electronic states in van der Waals materials, has predominantly focused on small-angle regime. Here, we unveil the pivotal role of intervalley Umklapp scattering in large-angle twisted bilayer graphene, which governs low-energy physics and drives unconventional band topology. By constructing symmetry-constrained effective $ k\cdot p$ models for $ \pm 21.8^{\circ}$ -twisted bilayers, we demonstrate how structural chirality imprints distinct electronic responses. The $ D_6$ configuration exhibits a gapped spectrum with chiral interlayer coupling, while $ D_3$ symmetric stacking configuration displays semimetallic behavior. Crucially, chirality inversion creates topological domain-wall states, which manifest as counterpropagating pseudospin modes at interfaces between oppositely twisted regions. These states, absent in untwisted bilayers, emerge from a Jackiw-Rebbi-like mechanism tied to chirality reversal. Atomistic simulations confirm these topological states and demonstrate their robustness against symmetry-breaking perturbations. The interplay between twist-induced chirality and topology opens new pathways for engineering domain-wall states in twisted materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
8 pages, 7 figures
A comparative study of the high-pressure structural stability of zirconolite materials for nuclear waste immobilisation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Daniel Errandonea, Robin Turnbull, Josu Sanchez-Martin, Robert Oliva, Alfonso Munoz, Silvana Radescu, Andres Mujica, Lewis Blackburn, Neil C. Hyatt, Catalin Popescu, Jordi Ibanez-Insa
We present a comparative study of the high-pressure behaviours of the nuclear waste immobilisation materials zirconolite-2M, -4M, -3O, and -3T. The materials are studied under high-pressure conditions using synchrotron powder X-ray diffraction. For zirconolite-2M we also performed density-functional theory calculations. A new triclinic crystal structure (space group P-1), instead of the previously assigned monoclinic structure (space group C2/c) is proposed for zirconolite-2M. We named the triclinic structure as zirconolite-2TR. We also found that zirconolite-2TR undergoes a phase transition at 14.7 GPa to a monoclinic structure described by space group C2/c, which is different than the high-pressure structure previously proposed in the literature. These results are discussed in comparison with previous studies on zirconolite-2M and the related compound calzirtite. For the other three zirconolite structures (4M, 3O, and 3T) this is the first high-pressure study, and we find no evidence for pressure induced phase transitions in any of them. The linear compressibility of the studied compounds, as well as a room-temperature pressure-volume equation of state, are also presented and discussed.
Materials Science (cond-mat.mtrl-sci), Geophysics (physics.geo-ph)
37 pages, 16 figures, 9 tables
Results in Physics 61, 2024, 107704
Quench dynamics of disordered quadrupolar Bose-Einstein condensates
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-08-07 20:00 EDT
We systematically investigate the equilibrium and the nonequilibrium quench dynamics of three-dimensional disordered quadrupolar Bose-Einstein condensates. Within the Bogoliubov-Huang-Meng approximation, we show that the combined effect of quenched interactions, disorder and excitations may modify the static as well as the dynamic properties of the system. The validity criterion of the developed approach is accurately established. By quenching the interaction strength, we reveal that the quantum depletion and the deformation condensate induced by disorder are enhanced in the asymptotic steady state compared to the corresponding equilibrium values. The time evolution of the condensate deformation is accompanied by damped oscillations with amplitudes strongly depend on the disorder correlation length and on the relative quadrupolar interaction.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
8 pages, 6 figures
Eur. Phys. J. Plus 140, 728 (2025)
Absence of dissipation-free topological edge states in quadratic open fermions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
We prove a no-go theorem that generic quadratic open fermionic systems, governed by Lindblad master equations, cannot host dissipation-free topological edge states. Drawing an analogy to topological insulators and superconductors, we map the Lindbladian to a first-quantized matrix representation that encodes the band structure, whose zero-energy topological edge modes are exactly dissipation-free. This matrix, however, is always adiabatically connected to a topologically trivial matrix, even under symmetry constraints. We formulate s rigorous adiabatic path to demonstrate this property. Thus, there is no robust dissipation-free edge modes protected by the bulk topology in quadratic open fermions, under any unitary or anti-unitary symmetries. Our result applies to generic quadratic fermionic Lindbladians, requiring only gapped bulk and bounded spectrum for technical convenience. Our result establish a definitive boundary for the existence of robust topological phenomena in open fermionic systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
6+2 pages, 1 figure. Comments are welcome!
Effects of symmetry on coupled rotary molecular motors
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-07 20:00 EDT
Sara Iranbakhsh, David A. Sivak
As engineering advances toward the nanoscale, understanding design principles for molecular motors becomes increasingly valuable. Many molecular motors consist of coupled components transducing one free-energy source into another. Here, we study the performance of coupled rotary molecular motors with different rotational symmetries under constant and scaling driving forces. Under constant driving and strong coupling, symmetry match between the motors decreases the output power. In contrast, under a scaling driving force, the output power is not sensitive to symmetries. However, driving the upstream motor too strongly reduces the downstream motor’s output power, leading to a perhaps counterintuitive phenomenon we term disruption, in which the two motors become disconnected. Across both driving schemes, output power peaks at intermediate coupling, confirming the value of flexible coupling. Beyond providing insights into biological motors, these findings could inform the future design of synthetic nanomotors and structure-based drugs.
Statistical Mechanics (cond-mat.stat-mech)
Main text: 5 pages and 5 figures; SM: 8 pages and 9 figures
Microwave characterization of superconducting coplanar resonators made out of granular aluminium
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-07 20:00 EDT
Kelvin J. Ramos, Ivana Curci, Erick Potosí, Ignacio Lobato, Leonardo Salazar Alarcón, Hernán Pastoriza, Leandro Tosi
We have designed, fabricated and characterized microwave resonators made out of thin films of granular aluminium (grAl) with different oxygen content. We extract the contribution of the large kinetic-inductance of this disordered superconductor from the frequency shift of the resonators as a function of temperature, and discuss the correlation with the resistivity of the films. At low temperatures, measurements of the internal quality factor as a function of microwave power indicate the presence of two-level systems, which are inherent to the growth process of the granular aluminium. The characterization methods presented here may be useful for the design of MKIDs, high-impedance resonators and superinductors.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
13 pages, 9 figures
Orientational Disorder of NH$_3$ in Hexammine Magnesium Borohydride
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Liam A. V. Nagle-Cocco, Andreas Schneemann, Kevin H. Stone, Vitalie Stavila, Thomas Gennett, Nicholas A. Strange
Hexammine magnesium borohydride, Mg(NH$ _3$ )$ _6$ (BH$ _4$ )$ _2$ , consists of adducted NH$ _3$ molecules locked in a matrix of Mg cations and borohydride anions. It is a candidate material for hydrogen storage, with 16.8wt% hydrogen stored in both the NH$ _3$ and borohydride anions. It also may be of interest as a Mg$ ^{2+}$ conducting electrolyte in solid state batteries. Its crystal structure has, until now, eluded a proper structural solution due to ambiguity regarding the NH$ _3$ position and behaviour. In this work, we show using synchrotron X-ray diffraction that the room-temperature structure can be solved only with a model assuming orientational disorder of ammonia molecules within the crystal structure. Cooling the sample to 120,K yields additional Bragg peaks, which can only be solved with a unit cell expansion consistent with a freezing of the orientational freedom of ammonia molecules. Using this insight from the structure solution, we perform a full assignment of the vibrational modes in the room-temperature IR spectrum.
Materials Science (cond-mat.mtrl-sci)
In press at ACS Inorganic Chemistry
The role of orbital polarization and spin-dependent electron-phonon scatterings in chiral-induced spin selectivity
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Mayank Gupta, Andrew Grieder, Mayada Fadel, Jacopo Simoni, Junting Yu, Ravishankar Sundararaman, Yuan Ping
Chiral materials exhibit unique spin and charge transport properties, notably through the chiral induced spin selectivity (CISS) effect, enabling spin-polarized currents in nonmagnetic materials without external magnetic fields at room temperature. In this study, we investigate the microscopic mechanisms underlying CISS in a prototypical chiral solid, trigonal selenium (Se), based on a first principles spatial-temporal resolved density-matrix dynamics approach, including electron-phonon scattering with self-consistent spin-orbit couplings (SOC). Our approach elucidates the interplay of SOC, structural chirality, and spin-dependent electron-phonon interactions in driving the generation and transport of spin and orbital angular momentum. We demonstrate that charge transport along the chiral axis induces significant chirality-dependent spin and orbital polarization, which shows a monotonic increase with higher chirality. Meanwhile, we show the orbital polarization generated in CISS has a weak dependence on SOC, unlike spin. Most importantly, we reveal the key difference between the CISS and colinear Edelstein effect (CEE) originating from spin-dependent electron-phonon scatterings, which explains the spin polarization increase with device lengths, a unique feature in CISS.
Materials Science (cond-mat.mtrl-sci)
Longitudinal magnons in large-$S$ easy-axis magnets
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-07 20:00 EDT
A. El Mendili, T. Ziman, M. E. Zhitomirsky
Longitudinal magnons are a novel class of multipolar quantum excitations in magnetic materials with large spins $ S\ge 1$ and strong easy-axis anisotropy. These excitations have angular momentum $ S^z = \pm 2S$ and can be viewed as propagating spin reversals. We study a simple model for longitudinal magnons: a square lattice of spins $ S$ coupled by the neareast-neighbor exchange, ferro- or antiferromagnetic, in the presence of a single-ion anisotropy. We calculate the excitation spectra in the large-$ D$ limit by using a strong-coupling expansion. In the specific case of $ S=1$ we compare the results for several analytical approaches that include the linked-cluster expansion, the multiboson representation of spin operators, and also, for a ferromagnetic ground state, the exact solution of the two-particle bound states. Among these different approaches, the multiboson theory gives the decay rate of longitudinal magnons and describes the evolution of the excitation spectra from strong to moderate and weak anisotropy.
Strongly Correlated Electrons (cond-mat.str-el)
Composite Fermion Theory of Fractional Chern Insulator Stability
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-07 20:00 EDT
Xiaodong Hu, Ying Ran, Di Xiao
We develop a mean-field theory of the stability of fractional Chern insulators based on the dipole picture of composite fermions (CFs). We construct CFs by binding vortices to Bloch electrons and derive a CF single-particle Hamiltonian that describes a Hofstadter problem in the enlarged CF Hilbert space, with the well-known trace condition emerging naturally in the small-$ q$ limit. Applied to twisted MoTe$ _2$ , the calculated CF phase diagram matches closely with that from exact diagonalization, and the projected many-body wavefunctions achieve exceptionally high overlaps with the latter. Our theory provides both a microscopic understanding and a computationally efficient tool for identifying fractional Chern insulators.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Hybrid metal-semiconductor quantum dots in InAs as a platform for quantum simulation
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
Praveen Sriram, Connie L. Hsueh, Karna A. Morey, Tiantian Wang, Candice Thomas, Geoffrey C. Gardner, Marc A. Kastner, Michael J. Manfra, David Goldhaber-Gordon
Arrays of hybrid metal-semiconductor islands offer a new approach to quantum simulation, with key advantages over arrays of conventional quantum dots. Because the metallic component of these hybrid islands has a quasi-continuous level spectrum, each site in an array can be effectively electronically identical; in contrast, each conventional semiconductor quantum dot has its own spectral fingerprint. Meanwhile, the semiconductor component retains gate-tunability of intersite coupling. This combination creates a scalable platform for simulating correlated ground states driven by Coulomb interactions. We report the fabrication and characterization of hybrid metal-semiconductor islands, featuring a submicron metallic component transparently contacting a gate-confined region of an InAs quantum well with tunable couplings to macroscopic leads. Tuning to the weak-coupling limit forms a single-electron transistor with highly-uniform Coulomb peaks, with no resolvable excitation spectrum in the Coulomb diamonds. Upon increasing the transmissions toward the ballistic regime we observe an evolution to dynamical Coulomb blockade.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Main text (14 pages, 6 figures), Supplemental Material (15 pages, 7 figures)
Angle-resolved photoemission intensity for multi-orbital bands: Complex interplay between the self-energy matrix and the optical matrix elements
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-07 20:00 EDT
Yau Chuen Yam, Mona Berciu, George A. Sawayzky
We use a simple one-dimensional two-band model with electron-phonon coupling to illustrate some of the complications that arise in multi-band systems when trying to extract a self-energy using the typical approach used for single-band systems when analyzing angle-resolved photoemission spectroscopy (ARPES) data. The underlying reason is that in multi-band models the self-energy is a matrix, not a scalar, and the result obtained from the ARPES analysis is a complicated function of all these self-energy matrix elements, weighted by different dipole matrix elements of the relevant Wannier orbitals. We contrast the results for Holstein and Peierls electron-phonon couplings to further illustrate differences between models with a local versus non-local self-energy matrix.
Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 11 figures
Transmon qubit using Sn as a junction superconductor
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
Amrita Purkayastha, Amritesh Sharma, Param J. Patel, An-Hsi Chen, Connor P. Dempsey, Shreyas Asodekar, Subhayan Sinha, Maxime Tomasian, Mihir Pendharkar, Christopher J. Palmstrøm, Moïra Hocevar, Kun Zuo, Michael Hatridge, Sergey M. Frolov
Superconductor qubits typically use aluminum-aluminum oxide tunnel junctions to provide the non-linear inductance. Junctions with semiconductor barriers make it possible to vary the superconductor material and explore beyond aluminum. We use InAs semiconductor nanowires coated with thin superconducting shells of beta-Sn to realize transmon qubits. By tuning the Josephson energy with a gate voltage, we adjust the qubit frequency over a range of 3 GHz. The longest energy relaxation time, T1 = 27 microseconds, is obtained at the lowest qubit frequencies, while the longest echo dephasing time, T2 = 1.8 microseconds, is achieved at higher frequencies. We assess the possible factors limiting coherence times in these devices and discuss steps to enhance performance through improvements in materials fabrication and circuit design.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
Data and code available at this https URL
EAC-Net: Real-space charge density via equivariant atomic contributions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Qin Xuejian, Lv Taoyuze, Zhong Zhicheng
Charge density is a fundamental quantity in quantum simulations, yet its accurate computation remains a major bottleneck. We present the Equivariant Atomic Contribution Network (EAC-Net), a deep learning framework for efficient and accurate charge density prediction. By introducing an atom-grid coupling mechanism, EAC-Net integrates the strengths of grid-based and basis-function-based models, achieving simultaneous improvements in accuracy and efficiency. We evaluated EAC-Net on a wide variety of systems, including amorphous solids, molecular liquids, surface structures, and metallic alloys, and found that it consistently achieves high accuracy with prediction errors typically below 1%. We further develop EAC-mp by training on Material Project’s CHGCAR datasets, which achieves state-of-the-art accuracy comparable to existing large charge density models while providing atomic-decomposed charge densities. The model demonstrates strong zero-shot prediction capabilities across diverse material systems. Moreover, EAC-Net generalizes well beyond the training distribution, supporting downstream applications such as non-self-consistent band structure calculations under structural perturbations. By bridging local chemical environments and global charge distributions, EAC-Net provides a scalable and general framework for accelerating electronic structure prediction, with potential applications in high-throughput materials screening and machine-learning-driven simulation workflows.
Materials Science (cond-mat.mtrl-sci)
21pages, 5figures
Competing Magnetic Phases in Li-Fe-Ge Kagome Systems
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Zhen Zhang, Kirill D. Belashchenko, Xiaoyi Su, Atreyee Das, Sergey L. Bud’ko, Paul C. Canfield, Vladimir Antropov
Competing interlayer magnetic interactions in kagome magnets can lead to diverse magnetic phases, which enable various promising topological or quantum material properties. Here, the electronic structure and magnetic properties have been studied using first-principles calculations for the LiFe$ _6$ Ge$ _6$ , LiFe$ _6$ Ge$ _4$ , and LiFe$ _6$ Ge$ _5$ compounds sharing the kagome Fe$ _3$ Ge layer motif but with different interlayer arrangements. For LiFe$ _6$ Ge$ _4$ and LiFe$ _6$ Ge$ _5$ , the predicted magnetic ground states are collinear antiferromagnetic (AFM) states involving a mix of ferromagnetic (FM) and AFM interlayer orientations. Whereas for LiFe$ _6$ Ge$ _6$ , an incommensurate cycloidal spin spiral is stabilized as a ground state, being close to a collinear A-type AFM state. The analysis of magnetic RKKY exchange coupling confirms the results of electronic structure calculations. The values of atomic magnetic moments are in good agreement with existing experimental estimations. Our experiments on LiFe$ _6$ Ge$ _6$ single crystals have observed AFM ordering at ~540 K and spin-reorientation transition with a small FM component (possibly with spin canting) below ~270 K. Thus, both theory and experiment independently suggest the existence and sequence of non-collinear and collinear magnetic states in kagome LiFe$ _6$ Ge$ _6$ . Our findings provide a platform for exploring various novel magnetic phases and associated unconventional or topological magnetism.
Materials Science (cond-mat.mtrl-sci)
Accelerating Discovery of Ternary Chiral Materials via Large-Scale Random Crystal Structure Prediction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Jiexi Song, Diwei Shi, Fengyuan Xuan, Chongde Cao
Chiral inorganic crystals with topological characteristics, prized for their exotic properties and fundamental interest, remain scarce in existing database. This work establishes a viable route for their large-scale discovery by integrating universal machine learning interatomic potentials (uMLIPs) for high-throughput structure optimization with the broad exploration capability of Random Structure Search (RSS). We implemented this combined uMLIP-RSS workflow to perform massive variable-composition crystal structure prediction across ternary systems, specifically targeting chiral space groups. High-throughput uMLIP-based optimization and stability screening of over 20 million randomly generated chiral structures identified numerous potentially stable phases out of existing database. Subsequent validation by first-principles confirmed over 120 new chiral inorganic crystals with promising functional applications, including topological characteristics, nonlinear optics, and superconductivity. Notably, this set includes materials exhibiting remarkable quantum phenomena, such as the nonlinear Hall effect driven by berry curvature dipole, quantum metric and symmetry-enforced six-fold topological points, long Fermi arcs and large magnetoresistance. This work substantially expands the pool of chiral functional materials and demonstrates a scalable, efficient strategy for predictive discovery in complex materials.
Materials Science (cond-mat.mtrl-sci)
Dynamical generation of geometric squeezing in interacting Bose-Einstein condensates
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-07 20:00 EDT
Li Chen, Fei Zhu, Zheng Tang, Liang Zeng, Jae Joon Lee, Han Pu
When the rotating frequency of a non-interacting Bose-Einstein condensate (BEC) confined in a weak anisotropic harmonic potential is suddenly quenched to its trapping frequency, the condensate evolves from its ground state to a single-mode squeezed state with exponentially growing quantum fluctuation anisotropy. Such a squeezed state is called the geometrically squeezed state. However, for interacting BECs with two-body collisions, a similar quench only results in quantum fluctuations oscillating periodically without squeezing. In this work, we identify superfluid stability as the key factor behind this non-squeezing phenomenon, with the periodic oscillations arising from collective excitations of a stable collective excitation mode. By strategically breaking the stability criteria, we propose a dynamical approach for generating squeezing that can exponentially suppress quantum fluctuations in a relatively short time, surpassing the efficiency of existing experimental preparation schemes.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
9 pages, 7 figures
Chern-Simons type cross-correlations and geometric Born effective charge of phonons
New Submission | Other Condensed Matter (cond-mat.other) | 2025-08-07 20:00 EDT
The interplay between different degrees of freedom in condensed matter systems engenders a rich variety of emergent phenomena. In particular, fermions with non-trivial quantum geometry can generate Chern-Simons (CS)-like terms in effective field theories for different gauge fields. For phonons, such terms can result in chiral phonon splitting. Here, we propose that the local Berry curvature can influence the spectra and dynamics of optical phonons, even in materials with zero Chern number, which we demonstrate with a gapped Dirac model. We identify a previously overlooked CS like cross-correlation between electromagnetic and pseudo-gauge fields in 2+1 dimensions which depends on valley Chern number. It facilitates a direct coupling between phonons and photons by inducing a geometric Born effective charge. This opens up a new route for coherent Raman phonon excitation and quantum geometry probes.
Other Condensed Matter (cond-mat.other)
5 pages, 4 figures
Four-mode quantum sensing and Fisher information in a spin-orbit-coupled Bose gas
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-07 20:00 EDT
Fei Zhu, Zheng Tang, Liang Zeng, Shu Wang, Li Chen
Multi-mode squeezing and entanglement are important resources in quantum metrology and sensing. For spin-1/2 Bose-Einstein condensates subject to spin-orbit coupling (SOC), previous studies on spin squeezing have been limited to two-mode systems. In this work, we demonstrate that such a system can naturally construct a four-mode model spanning an $ \mathfrak{su}(4)$ algebra with six SU(2) subspaces. Using spin squeezing parameters and quantum Fisher information matrices, we analyze the dynamical evolution of coherent spin states. The results show that, beyond two-mode models, the SOC-induced four-mode couplings give rise to richer entanglement-enhanced sensing approaching the Heisenberg limit across various SU(2) subspaces. Additionally, by tuning a single system parameter (the Raman Rabi frequency), one can selectively control the optimal measurement directions across different subspaces.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
9 pages, 5 figures
Straightforward Method to Orient Black Phosphorus from Bulk to Thin Layers using a Standard Green Laser
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
Etienne Carré, Frédéric Fossard, Jean-Sébastien Mérot, Denis Boivin, Nicolas Horezan, Victor Zatko, Florian Godel, Bruno Dlubak, Marie-Blandine Martin, Pierre Seneor, Etienne Gaufres, Julien Barjon, Annick Loiseau, Ingrid Stenger
The crystallographic orientation of anisotropic 2D materials plays a crucial role in their physical properties and device performance. However, standard orientation techniques such as transmission electron microscopy (TEM) or X-ray diffraction (XRD) can be complex and less accessible for routine characterization. In this study, we investigate the orientation of black phosphorus (BP) from bulk crystals to thin layers using angle-resolved polarized Raman spectroscopy (ARPRS) with a single-wavelength (514 nm) Raman setup. By incorporating thickness-dependent interference effects and anisotropic optical indices, this approach provides a reliable framework for orientation determination across different BP thicknesses. The method is validated through direct orientation measurements using TEM and Electron Backscattering Diffraction (EBSD), confirming its applicability to both thick and ultrathin samples. Given its simplicity and compatibility with widely available Raman setups, this approach offers a practical solution for characterizing BP orientation without requiring advanced structural characterization techniques.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
ChemNanoMat 250018 (2025)
Non-Equilibrium Dynamics and First-Passage Properties of Stochastic Processes: From Brownian Motion to Active Particles
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-07 20:00 EDT
In this thesis, we develop analytical methods to study out-of-equilibrium stochastic processes driven by colored noise, i.e., noise with temporal correlations. These non-Markovian processes pose significant analytical challenges compared to processes driven by white noise, such as Brownian motion. A primary focus is on active particle systems, specifically the run-and-tumble particle subjected to an arbitrary force. We derive exact expressions for its mean first-passage time (MFPT) and exit probability from an interval using the backward Fokker-Planck equation. Remarkably, we find that the MFPT can be optimized as a function of the tumbling rate. Additionally, we investigate stochastic resetting and switching diffusion models. For switching diffusion models which are examples of “Brownian yet non-Gaussian diffusions”, we use a renewal approach and large deviation theory to derive exact results for various observables. These include the distribution of the position of the particle and its moments, but also its cumulants which are key observables to characterize non-Gaussian fluctuations. Notably, we uncover an unexpected connection between this model and free cumulants. We also examine these models in the presence of a harmonic potential by using Kesten variables. This approach enables us to write an integral equation for the steady-state distribution, which we solve in specific cases. Furthermore, we extend Siegmund duality - a concept that is not widely known in the physics literature - to active particles, random diffusion models, stochastic resetting, and continuous-time random walks. This duality establishes a direct relation between first passage observables and the spatial properties of a dual process, which we explicitly construct.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Soft Condensed Matter (cond-mat.soft), Mathematical Physics (math-ph), Probability (math.PR)
PhD thesis defended on June 16, 2025 at Sorbonne Université, Paris. 252 pages
Effect of screening on Seebeck coefficient in bilayer graphene/AlGaAs electron gas
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
Vo Van Tai, Nguyen Duy Vy, Truong Van Tuan, Nguyen Quoc Khanh
The knowledge of Seebeck coefficient is a key factor in optimization of thermoelectric materials and finding right applications for it. A high sensitivity to structural change makes thermopower measurements an excellent technique for the study on the charge transport properties of a given material. The phonondrag term dominates at low temperature in the Seebeck coefficient This study examines the temperaturedependent screening effect on the phonondraginduced Seebeck coefficient S^g in a bilayer graphene- BLG-AlGaAs-quasi-twodimensional electron gas (q2DEG) system at the temperature below 50 K. The BLG layer interacts with both deformation potential acoustic phonons and stronger piezoelectric field acoustic phonons from AlGaAs/GaAs. We compare the electronphonon interactions in BLG with and without screening by q2DEG. The screening effect reduces particularly at low temperatures and shows a strong dependence on the carrier density in the BLG layer. The doublelayer screening function increases with layer separation d paralleling the monolayer screening at large d. Additionally varying the GaAs quantum well width reveals that increases with width less than 100 Åunder doublelayer screening but remains unchanged beyond this threshold while monolayer screening decreases as the width increases. Both screening functions enhance when the BLG carrier density is lower than that of q2DEG though the magnitude difference between them is minimal
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
$\boldsymbol{d}$-vector precession induced pumping in topological $p$-wave superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-07 20:00 EDT
Time-reversal invariant $ p$ -wave superconductors (SCs) are characterized by their $ \boldsymbol{d}$ -vectors, whose orientations could be manipulated by a tiny magnetic field. We study in this paper the adiabatic pumping process induced by periodically rotating $ \boldsymbol{d}$ -vector in a topological $ p$ -wave SC, which is coupled to two normal leads. If $ \boldsymbol{d}$ -vector rotates nearly within a plane, the pumped spin $ 2S_z/\hbar$ over one cycle is nearly quantized at $ 2$ without net charge pumping. When the pumping lead is fully spin-polarized, both the pumped charge $ Q/e$ and spin $ 2S_z/\hbar$ would peak nearly at $ 1$ . When a mixing $ s$ -wave pairing component is taken into account, a topological phase transition can be driven by modulating the ratio between the pairing components. We found a sharp resonance phenomenon near the phase transition when the $ p$ -wave $ \boldsymbol{d}$ -vector is adiabatically rotating, which may help experimentally distinguish the topological SCs from trivial ones.
Superconductivity (cond-mat.supr-con)
16 pages, 8 figures
Symmetric versus antisymmetric strain tuning of the valence transition in Yb(In$_{1-x}$Ag$_x$)Cu$_4$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-07 20:00 EDT
Caitlin I. O’Neil, Michelle Ocker, Kristin Kliemt, Cornelius Krellner, Elena Gati
Similar to transitions in a range of correlated quantum materials, the valence transition exhibits a strong coupling to the crystal lattice, rendering it highly sensitive to stress tuning. In the present work, we determine the effect of uniaxial stress, which breaks the lattice symmetry, on the valence transition temperature and its crossover temperature in pure and Ag-substituted YbInCu$ _4$ . Our key result is that hydrostatic stress is more effective in tuning this transition than uniaxial stress. Based on a symmetry decomposition of the stress-induced strains, we argue that this observation can be quantitatively understood, given that the valence transition is mostly sensitive to symmetric strains and thus volume changes of the lattice. These results support the notion that the valence transition can give rise to critical elasticity close to its critical endpoint.
Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 3 figures
Cooperative Jahn-Teller dynamics of boron clusters in the infrared conductivity of heavy fermion metal CeB6 and unconventional superconductor ZrB12
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-07 20:00 EDT
Gennady Komandin, Elena Zhukova, Boris Gorshunov, Andrey Azarevich, Andrey Muratov, Yurii Aleshchenko, Nikolay Sluchanko
A thorough study of the wide-range (40-35000 cm-1) dynamic conductivity and permittivity spectra of the archetypal heavy fermion metal CeB6 and unconventional superconductor ZrB12 was carried out at room temperature. Both the Drude-type components and overdamped excitations were separated and analyzed. An additional absorption band observed above 200 cm-1 was attributed to the cooperative Jahn-Teller dynamics of the boron complexes in CeB6 and ZrB12. It was shown that nonequilibrium electrons participating in the formation of the collective JT modes dominate in charge transport, and fraction of Drude-type electrons does not exceed 37% in CeB6 and 23% in ZrB12. We discuss also the additional Drude-type component in ZrB12 in terms of far-infrared conductivity from the sliding charge density wave, and suggest the localized mode scenario reconciles the strong difference between the number of conduction electrons obtained from the Hall effect and optical sum rule analysis in CeB6.
Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 3 figures, 2 tables
Suspensions of small ultra-soft colloids remain liquids in overcrowded conditions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
Nikolaos A. Burger, Alexander V. Petrunin, Ann E. Terry Ralf Schweins, Andrea Scotti
Concentrated suspensions of small ultra-soft colloids (ultra-low crosslinked microgels) are investigated with scattering and steady shear rheology to capture their equilibrium dynamics. The suspensions lack dynamic arrest, although the slow relaxation time $ \tau_2$ follows exponential growth with increasing generalized packing fraction, $ \zeta$ . The zero-shear viscosity grows weakly with $ \zeta$ , and never diverges in contrast to other soft glass formers, e.g.~star-polymers, microgels, green particles. Their high compressibility allows these ultra-soft spheres to diffuse even in overcrowded environments.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
Thermoresponsive copolymer microgels synthesized via single-step precipitation polymerization: random or block structure?
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
Letizia Tavagnacco, Elena Buratti, Jacopo Vialetto, Francesco Brasili, Elisa Ballin, Kuno Schwärzer, Jitendra Mata, Graziano Di Carmine, Monica Bertoldo, Ester Chiessi, Marco Laurati, Emanuela Zaccarelli
The inner structure of polymeric particles critically influences their phase behavior and functionality, governing their mechanical properties and their physical and chemical interactions. For thermoresponsive microgels, i.e. colloidal particles comprising a crosslinked polymer network that undergo a volume transition upon temperature changes, structural control is key to tailor the material responsivity and broaden the range of applications. In this work, we present a comprehensive investigation of the internal structure of poly(N-isopropylacrylamide-co-N-isopropylmethacrylamide), P(NIPAM-co-NIPMAM), copolymer microgels, combining small-angle neutron scattering (SANS), dynamic light scattering (DLS), and nuclear magnetic resonance (NMR) measurements with multi-scale simulations. By synthesizing different samples, we probe the microgels swelling behavior, revealing distinct signatures of the individual polymers. To elucidate their internal distribution, we perform monomer-resolved microgel simulations across different copolymer models. A direct comparison between experimental and numerical form factors under different, neutron-selective conditions provides evidence of a preferential organization into block structures rather than a random arrangement. These results are confirmed by 13C-NMR which reveals the clear presence of NIPAM blocks within a more random arrangement of the remaining monomers and by atomistic molecular dynamics simulations on copolymer chains, which also shed light on a possible origin in the dependence of the hydrogen bonding capability on the local environment. These findings provide a detailed microscopic picture of the inner architecture of P(NIPAM-co-NIPMAM) microgels, revealing an unexpected structural organization that may be generalized to other copolymer systems and could be promising to tailor microgel design and enhance control of material responsivity.
Soft Condensed Matter (cond-mat.soft)
Open Gas-Cell Transmission Electron Microscopy at 50 pm Resolution
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Idan Biran, Frederik Dam, Sophie Kargo Kaptain, Ruben Bueno Villoro, Maarten Wirix, Christian Kisielowski, Peter C. K. Vesborg, Jakob Kibsgaard, Thomas Bligaard, Christian D. Damsgaard, Joerg R. Jinschek, Stig Helveg
Transmission electron microscopy (TEM) has reached ~ 50 picometer resolution in a high vacuum, enabling single-atom sensitive imaging of nanomaterials. Extending this capability to gaseous environments would allow for similar visualizations of nanomaterial dynamics under chemically reactive conditions. Here, we examine a new TEM system that maintains 50 pm resolution at pressures up to 1 mbar, demonstrated using nanocrystalline Au immersed in N2. The system features an open gas-cell with a four-stage differential pumping system, a 5th order aberration corrector for broad-beam TEM, a monochromatized electron beam, an ultra-stable microscope platform, Nelsonian low electron dose-rate illumination, and direct electron detection. Young fringe experiments and exit wave phase imaging confirm the atomic resolution and indicate location-dependent vibrational blur at surface terminations. Thus, this platform advances in situ and operando TEM studies of gas-surface interactions in diverse fields, including catalysis, corrosion, and crystal growth.
Materials Science (cond-mat.mtrl-sci)
Sterol-induced raftlike domains in a model lipid monolayer
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
S. Siva Nasarayya Chari, Bharat Kumar
A two-dimensional system consisting a mixture of higly coarse-grained saturated (S-type), unsaturated (U-type) lipid molecules, and cholesterol (C-type) molecules is considered to form a model lipid monolayer. All the S-, U- and C-type particles are spherical in shape, with distinct interaction strengths. The phase behavior of the system is studied for various compositions ($ x$ ) of the C-type particles, ranging from $ x = 0.1$ to $ 0.9$ . The results show that a structurally ordered complex is formed with the S- and C-types in the fluid-like environment of U-type particles, for $ x \in \lbrace 0.5 - 0.6\rbrace$ . The time-averaged hexatic order parameter $ \left\langle \Psi_{6} \right\rangle$ indicates that the dynamical segregation of S- and C-types exhibits a positional order, that is found to be maximum for $ x$ in the range of 0.5 - 0.6. The mean change in the free energy ($ \Delta G(x)$ ) obtained from the mean change in enthalpy ($ \Delta H$ ) and entropy ($ \Delta S$ ) calculations suggests that $ \Delta G$ is minimum for $ x \sim 0.6$ . A phenomenological expression for the Gibbs free energy is formulated by explicitly accounting for the individual free energies of S-,U- and C-type particles and the mutual interactions between them. Minimizing this phenomenological $ G$ with respect to the C-type composition results in the optimal value, $ x^\ast = 0.564 \pm 0.001$ for stable coexistence of phases; consistent with the simulation results and also the previous experimental observations \cite{raghavendra_effect_2023}. All these observations signifies the optimal C-type composition, $ x \sim 0.5 - 0.6$ .
Soft Condensed Matter (cond-mat.soft)
Is the cortical dynamics ergodic? A numerical study in partially symmetric networks of spiking neurons
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-08-07 20:00 EDT
Ferdinand Tixidre, Gianluigi Mongillo, Alessandro Torcini
Cortical activity in-vivo displays relaxational time scales much longer than the membrane time constant of the neurons or the deactivation time of ionotropic synaptic conductances. The mechanisms responsible for such slow dynamics are not understood. Here, we show that slow dynamics naturally and robustly emerges in dynamically-balanced networks of spiking neurons. This requires only partial symmetry in the synaptic connectivity, a feature of local cortical networks observed in experiments. The symmetry generates an effective, excitatory self-coupling of the neurons that leads to long-lived fluctuations in the network activity, without destroying the dynamical balance. When the excitatory self-coupling is suitably strong, the same mechanism leads to multiple equilibrium states of the network dynamics. Our results reveal a novel dynamical regime of the collective activity in spiking networks, where the memory of the initial state persists for very long times and ergodicity is broken.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Ultrafast Raman probe of the photoinduced superconducting to normal state transition in the cuprate Bi$_2$Sr$_2$CaCu$2$O${8+δ}$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-07 20:00 EDT
Laurène Gatuingt, Alexandr Alekhin, Niloufar Nilforoushan, Sarah Houver, Alain Sacuto, Genda Gu, Yann Gallais
We report an ultrafast Time-Resolved Raman scattering study of the out-of-equilibrium photoinduced dynamics across the superconducting to normal state phase transition of the cuprate Bi$ _2$ Sr$ _2$ CaCu$ _2$ O$ _{8+\delta}$ . Using the polarization-resolved momentum space selectivity of Raman scattering, we track the superconducting condensate destruction and recovery with sub-ps resolution in the anti-nodal region of the Fermi surface where the superconducting gap is maximum. Leveraging ultrafast Raman thermometry, we find a significant dichotomy between the superconducting condensate and the quasiparticle temperature dynamics near the anti-nodes, which cannot be framed in terms of a single effective electron temperature. The present work demonstrates the ability of TR-Raman to selectively probe out-of-equilibrium pathways of different electron sub-degrees of freedom during a photoinduced phase transition.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 5 figures, 2 appendices
Theory of circular dichroism in resonant inelastic x-ray scattering
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
We analyze circular dichroism (CD) in resonant inelastic x-ray scattering (RIXS) in magnetic materials. We define RIXS-CD as the difference between scattering amplitudes for the right- and left-circularly polarized incoming photons and unpolarized (total) outgoing photons. We employ the impurity approximation, in which the interference between scattering events on different atoms is neglected. We perform the symmetry analysis of several common antiferromagnetic and altermagnetic structures and outline the general approach. The analysis is supported by numerical calculations using atomic model with realistic crystal fields obtained from first principles. We show that RIXS-CD is distinguished from first-order spectroscopies such as x-ray magnetic circular dichroism by insensitivity to the time-reversal symmetry breaking. As a result we find that RIXS-CD is present in the normal (disordered) state of materials with lower symmetry. In antiferromagnets the RIXS-CD is invariant under Néel vector reversal. In altermagnets and ferromagnets the RIXS-CD spectra for time-reversed states are, in general, independent except for the special case when there is a unitary symmetry of the Hamiltonian connecting the
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 7 figures
Anomalous Doppler effect in two-component Bose-Einstein condensates
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-07 20:00 EDT
Tomasz Zawiślak, Sandro Stringari, Alessio Recati
We show that two-component Bose-Einstein condensed mixtures, in presence of a persistent current, exhibit a non trivial Doppler shift of the sound velocities. The peculiarity is due to the inter-species interaction and the possibility of generating a counter-flow persistent current. Analytic predictions are derived by using superfluid hydrodynamics. While the existence of anomalous Doppler shifts at finite temperature has been discussed a long time ago in the case of superfluid Helium-4, an experimental verification of the effect is still missing. For this reason, we also propose a protocol for the measurement of the Doppler shifts, based on the density-density response function. The dynamical protocol is simulated by means of coupled Gross-Pitaevskii equations.
Quantum Gases (cond-mat.quant-gas)
Hydrodynamics of a three-dimensional mesoscale odd fluid
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
Odd fluids are a class of fluids characterized by non-zero antisymmetric transport coefficient tensors induced by broken time-reversal symmetry. In our previous work, a mesoscale simulation model for two-dimensional isotropic odd fluids was developed. Here, we extend the model to the three-dimensional case that corresponds to an anisotropic odd fluid with cylindrical symmetry. Using kinetic theory, we analytically derive the viscosity tensor and Navier-Stokes equation for the three-dimensional mesoscale odd fluid, which are quantitatively verified by simulations. Furthermore, through both simulation and hydrodynamic theory, we demonstrate that the planar Poiseuille flow of the three-dimensional odd fluid exhibits exotic transport behavior. This work thus paves the way for performing large-scale simulations to explore and exploit intriguing phenomena of odd fluids.
Soft Condensed Matter (cond-mat.soft)
Active Extensile Hydrogels Actuated by Living Polymers of the Bacterial Cytokinetic Protein FtsZ
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
Mikheil Kharbedia, Diego Herráez-Aguilar, Macarena Calero, Horacio López-Menéndez, Clara Luque-Rioja, Lara H. Moleiro, Cruz Santos, Pilar Lillo, Francisco Monroy
Active materials capable of autonomously modulating their mechanical properties are foundational to the development of next-generation soft technologies. Here, we introduce a novel class of extensible biohybrid hydrogels powered by living polymers of the bacterial cytokinetic protein FtsZ. When embedded within a polyacrylamide (PA) matrix, GTP-fueled FtsZ filaments self-organize into treadmilling structures that generate internal extensible stresses, driving reversible softening, swelling, and fluidization of the composite FtsZ-PA hydrogel network. Unlike conventional contractile biopolymer systems, these hybrid gels exhibit stress-induced softening, yield under minimal deformation, and suppress thermal flow barriers-hallmarks of dissipative, extensile metamaterials. Microscopic particle tracking reveals active non-Gaussian fluctuations, while bulk rheology confirms programmable, concentration-dependent reductions in both stiffness and viscosity. Theoretical modeling shows that internal filament activity gives rise to a negative mechanical permittivity, establishing a new paradigm in materials science in which embedded FtsZ living polymers dynamically program active matter mechanics from within. These findings open new avenues for the design of modular, reconfigurable systems in adaptive biomaterials, soft robotics, and synthetic active matter.
Soft Condensed Matter (cond-mat.soft)
Nematic chiral Superconductivity driven by chiral loop current order in kagome metals
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-07 20:00 EDT
Rina Tazai, Youichi Yamakawa, Hiroshi Kontani
The sequence of unconventional quantum phases in the kagome metal AV3Sb5 (A = Cs, Rb, K), including charge-density-wave and loop-current order, gives rise to exotic chiral electronic states that lack time-reversal symmetry (TRS). These unusual low-symmetry electronic states give rise to novel nonreciprocal transport and chiral quasiparticle-interference patterns. Especially, recent experiments have discovered pronounced nematicity and chirality in the superconducting (SC) state. The observed SC state exhibits high sensitively to external magnetic fields, strongly suggesting the breaking of TRS. Furthermore, a small amount of disorders leads to an isotropic s-wave state. In this study, we propose the mechanism of nematic chiral d-wave superconductivity in the presence of loop-current order, emerging from the attractive charge-channel pairing interaction that exists in real kagome metals. An chiral d-wave SC state, which has a nontrivial topological properties, is driven by the TRS breaking pair-hopping mechanism under a sole loop-current order. Notably, chiral SC state exhibits pronounced nematicity when the loop-current order and the Star-of-David charge-density-wave coexist, in spite of the fact that the Fermi surfaces possess almost perfect $ C_6$ symmetry. The chiral superconducting state arising from this mechanism is easily switched to conventional s-wave SC by introducing a small amount of impurities. Furthermore, the present mechanism yields a prominent 2x2 pair-density-wave component, consistent with experimental observations. The present study provides insights into the fundamental nature of exotic SC states arising from the loop-current phase in kagome metals.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 10 figures
Emergence of run-and-tumble-like swimming in self-propelling artificial swimmers in soft microchannels
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
Smita S. Sontakke, Aneesha Kajampady, Mohd Suhail Rizvi, Ranabir Dey
Biological microswimmers often encounter deformable boundaries in physiological conditions; for instance, the viscoelastic walls of reproductive tract during migration of spermatozoa, or host tissue during early bacterial biofilm formation. However, the combined influence of elastic and hydrodynamic cues on microswimmer dynamics is poorly understood. Here, we experimentally investigate how the softness of microchannel walls affects the swimming characteristics of self-propelling microswimmers, using autophoretic active droplets as a model system. Remarkably, in a soft microchannel, a self-propelling droplet exhibits a run-and-tumble-like motility characterized by abrupt reorientations in the swimming direction, which are accompanied by local reduction and subsequent increase in the swimming speed. Such emergent swimming dynamics in response to increasing softness of microchannels have been previously unobserved for synthetic microswimmers. Using 3D boundary integral simulations and fluorescence microscopy experiments, we show that the coupling between the elastohydrodynamic interactions and the chemo-hydrodynamics, inherent in the self-propulsion mechanism, in a soft narrow confinement results in alterations in the swimming characteristics. We envisage that such adaptation of autophoretic microswimmers to changes in the softness of microchannel walls will pave the way for novel methods for tuning active agents in complex environment solely by exploiting the elasticity of confining walls.
Soft Condensed Matter (cond-mat.soft)
Inelastic electron tunneling through adatoms and molecular nanomagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
Daria Kyvala, Jindrich Kolorenc
We discuss a theoretical description of the inelastic electron tunneling spectra (IETS) of a magnetic nanosystem (an atom or a molecule) adsorbed on a solid surface measured in a scanning tunneling microscope (STM). We represent the nanosystem by means of a cluster Hubbard model, which allows us to study scenarios when the tunneling electrons sequentially interact with several magnetic centers inside the nanosystem or when the magnetic centers are made out of heavy atoms with a strong spin-orbit coupling and large orbital moments. The sequential tunneling through multiple centers is illustrated on an adatom probed by an STM tip with a nickelocene molecule attached to it. For atoms with a large orbital moment, we find the transitions accessible by IETS to be governed by the selection rule $ \Delta J_z\leq 2\ell+1$ , where $ J_z$ is the projection of the total angular momentum of the atom to the quantization axis and $ \ell$ is the orbital momentum quantum number of the partially filled atomic shell carrying the magnetic moment. For atoms with magnetic moments dominated by spin, the spectra are naturally dominated by transitions fulfilling the traditional selection rule $ \Delta J_z\leq 1$ .
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 6 figures, 1 table + supplement (18 pages, 4 figures, 3 tables)
Reentrant topology and reverse pumping in a quasiperiodic flux ladder
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-07 20:00 EDT
Sanchayan Banerjee, Rajashri Parida, Tapan Mishra
Topological phases of matter are known to be unstable against strong onsite disorder in one dimension. In this work, however, we propose that in the case of a topological ladder, an onsite quasiperiodic disorder under proper conditions, first destroys the initial topological phase and subsequently, induces another topological phase through a gap-closing point. Remarkably, by allowing a staggered flux piercing through the plaquettes of the ladder, the gapless point bifurcates into two gapless critical lines, resulting in a trivial gapped phase sandwiched between the two topological phases. This results in a scenario where the system first undergoes a transition from one topological phase to a trivial phase and then to the other topological phase as a function of the quasiperiodic disorder strength. Such disorder induced re-entrant topological phase transition reveals a phenomenon of direction reversal in the topological transport, which we identify through Thouless charge pumping.
Quantum Gases (cond-mat.quant-gas), Other Condensed Matter (cond-mat.other)
5 pages, 4 figures
Edge modes of topological Mott insulators and deconfined quantum critical points
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-07 20:00 EDT
Yuhai Liu, Toshihiro Sato, Disha Hou, Zhenjiu Wang, Wenan Guo, Fakher F. Assaad
Topology and anomalies lead to edge modes that can interact with critical bulk fluctuations. To study this setup, pertaining to boundary criticality, we consider a model exhibiting a deconfined quantum critical point (DQCP) between a dynamically generated quantum spin Hall state (i.e.a topological Mott insulator) and an s-wave superconductor. For the topological Mott insulator, the bulk Goldstone modes are shown to be irrelevant at the helical Luttinger liquid fixed points. The deconfined quantum critical point is an instance of an emergent anomaly, and we observe a sharp localized edge state at this point. The sharpness of the edge mode is consistent with an ordinary phase in which electronic edge modes decouple from critical edge bosonic fluctuations. At the DQCP, the scaling dimension of the edge electron shows a jump, a feature argued to be a signature of the emergent anomaly. Our results are based on large-scale auxiliary-field quantum Monte Carlo this http URL also carry out calculations for the Kane-Mele-Hubbard model to confirm spectral features of the ordinary and extraordinary-log phases in the vicinity of the bulk critical point.
Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 8 figures
Odd elasticity in disordered chiral active materials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
Cheng-Tai Lee, Tom Lubensky, Tomer Markovich
Chiral active materials are abundant in nature, including the cytoskeleton with attached motor proteins, rotary clusters of bacteria flagella, and self-spinning starfish embryos. These materials break both time reversal and mirror-image (parity) symmetries due to injection of torques at the microscale. Recently, it was found that chiral active materials may show a new type of elastic response termed odd' elasticity. Currently, odd elasticity is understood microscopically only in ordered structures, e.g., lattice designs of metamaterials. It still remains to explore how odd elasticity can emerge in natural or biological systems, which are usually disordered. To address this, we propose a minimal generic model for disordered odd solids’, using micropolar (Cosserat) elasticity in the presence of local active torques. We find that odd elasticity naturally emerges as a nonlinear effect of internal particle rotations. Exploring the viscoelasticity of this solid, when immersed in active self-spinning solvent (`odd fluid’), we discover both dynamically unstable regions and regions in which bulk waves can propagate even in an overdamped solid.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
6 pages, 2 figures
Nature of field-induced transitions and hysteretic magnetoresistance in non-collinear antiferromagnet EuIn2As2
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Karan Singh, Jan Skolimowski, Giuseppe Cuono, Raghottam M. Sattigeri, Andrzej Ptok, Orest Pavlosiuk, Tetiana Romanova, Tomasz Tolinski, Piotr Wisniewski, Carmine Autieri, Dariusz Kaczorowski
We examine the magnetic and electrical transport properties of the hexagonal EuIn2As2 compound, combining experimental and theoretical results. This compound is predicted to be an axion-insulator from an electronic point of view and an altermagnet while in the collinear magnetic phase. However, experiments indicate that the Fermi level lies within the valence band rather than in the topological gap, potentially leading to the dominance of magnetic properties. Our detailed studies on magnetization and electrical transport support the presence of a broken-helix antiferromagnetic state, which was previously identified by X-ray and neutron diffraction experiments. Notably, we observed within that state a field-induced metamagnetic transition marked by a large hysteresis in magnetoresistance, which turns into a sharp upturn for the magnetic field tilted by 15 degree from the c-axis of the crystal. Combined with theoretical calculations, it is explained that the application of a magnetic field changes the low-resistivity antiferromagnetic domain walls to the high-resistivity domain walls due to the reduction in the Fermi surface sheets interaction area in the domain walls, originating from p-orbitals of As. EuIn2As2, therefore, presents a new case study that broadens the understanding of complex magnetic structures and their influence on electrical transport.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Structural and helix reversal defects of carbon nanosprings
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
Alexander V. Savin, Elena A. Korznikova, Sergey V. Dmitriev
Due to their chiral structure, carbon nanosprings possess unique properties that are promising for nanotechnology applications. The structural transformations of carbon nanosprings in the form of spiral macromolecules derived from planar coronene and kekulene molecules (graphene helicoids and spiral nanoribbons) are analyzed using molecular dynamics simulations. While the tension/compression of such nanosprings has been analyzed in the literature, this study investigates other modes of deformation, including bending and twisting. Depending on the geometric characteristics of the carbon nanosprings, the formation of structural and helix reversal defects is described. It is found that nanosprings demonstrate a significantly higher coefficient of axial thermal expansion than many metals and alloys. These results are useful for designing nanosensors that operate over a wide temperature range.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 14 figures
$β$-Irida-Graphene: A New 2D Carbon Allotrope for Sodium-Ion Battery Anodes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
José A. S. Laranjeira, Kleuton A. L. Lima, Nicolas F. Martins, Luiz A. Ribeiro Junior, Douglas S. Galvão, Luis A. Cabral, Julio R. Sambrano
The quest for sustainable and efficient energy storage has driven the exploration of sodium-ion batteries (SIBs) as promising alternatives to lithium-ion systems. However, the larger ionic radius of sodium poses intrinsic challenges such as slow diffusion and structural strain in conventional electrode materials. As a contribution to addressing these limitations, the \b{eta}-Irida-graphene ($ \beta$ -IG) is herein introduced, a novel two-dimensional (2D) carbon allotrope derived from Irida-graphene, featuring a diverse polygonal lattice of 3-, 4-, 6-, 8-, and 9-membered carbon rings. Through density functional theory and ab initio molecular dynamics simulations, $ \beta$ -IG demonstrated remarkable thermal, dynamical, and mechanical stability, coupled with intrinsic conductive character and efficient sodium-ion mobility (energy barriers < 0.30 eV). Furthermore, the adsorption of sodium ions was energetically favorable, delivering an impressive predicted specific capacity of 554.5 mAh/g. The reported findings highlight $ \beta$ -IG as a good potential anode candidate for next-generation SIBs, offering high-rate performance and structural robustness, and expanding the functional design space for advanced carbon-based electrode materials.
Materials Science (cond-mat.mtrl-sci)
Adiabatic protocol for the generalized Langevin equation
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-07 20:00 EDT
This article proposes a self-consistent methodology for determining the work involved in an adiabatic process where the dynamics of a Brownian particle is trapped in an optical tweezers. Instead of varying the frequency of the trap, it is displaced through a defined protocol. Assuming the dynamics follow a modified generalized Langevin equation previously proposed by the author, it is found that the external adiabatic driving is uniquely derived in terms of the system’s dynamical properties, and unlike isothermal processes, does not require optimization. There is no need to include other parameters than those characterizing the model.
Statistical Mechanics (cond-mat.stat-mech)
Density of States (Gate) - Controlled Andreev Molecule and Sensor
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
Xiaofan Shi, Ziwei Dou, Guoan Li, Dong Pan, Yuxiao Song, Anqi Wang, Zhiyuan Zhang, Xingchen Guo, Xiao Deng, Ruixuan Zhang, Liangqian Xu, Xiao Chen, Yupeng Li, Bingbing Tong, Xiaohui Song, Zhaozheng Lyu, Peiling Li, Fanming Qu, Guangtong Liu, Jianhua Zhao, Li Lu, Jie Shen
Topological quantum computing typically relies on topological Andreev bound states (ABSs) engineered in hybrid superconductor-semiconductor devices, where gate control offers key advantages. While strong Zeeman fields can induce such states, an alternative approach emerges through Andreev molecules – closely spaced, coupled ABSs, also key building-block for Kitaev chain – that enable topological behavior without high magnetic fields. However, existing Andreev molecules are controlled via magnetic flux in superconducting loops, limiting scalability. Here, we introduce a gate-controlled Andreev molecule, where electrostatic tuning of the density of states in one site nonlocally enhances the critical current of another. This eliminates superconducting loops, offering superior tunability, scalability, and sensitivity. We further extend such an Andreev molecule to a multi-site Kitaev chain, and a noninvasive sensor resolving single-Cooper-pair charge for parity readout. This platform bridges the gap between scalable ABS engineering and high-sensitivity quantum sensing, advancing the development for constructing and parity-readout in topological ABSs and long Kitaev chains towards topological qubits.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
Localization structure of electronic states in the quantum Hall effect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
We investigate the localization of electronic states in the Integer Quantum Hall Effect (IQHE) using a magnetic localization landscape (MLL) approach. By studying a continuum Schrödinger model with disordered electrostatic potential, we demonstrate that the MLL, defined via a modified landscape function incorporating magnetic effects, captures key features of quantum state localization. The MLL effective potential reveals the spatial confinement regions and provides predictions of eigenstate energies, particularly in regimes where traditional semiclassical approximations break down. Numerical simulations show that below a critical energy, states localize around minima of the effective potential, while above it, they cluster around maxima-with edge effects becoming significant near boundaries. Bridging the gap between semiclassical intuition and full quantum models, the MLL offers a robust framework to understand transport and localization in disordered quantum Hall systems, and extends the applicability of landscape theory to magnetic systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Disordered Systems and Neural Networks (cond-mat.dis-nn)
13 pages, 9 figures
Moisture-driven CO2 direct air capture and delivery for cultivating cyanobacteria
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
Justin Flory, Shuqin Li, Samantha Taylor, Sunil Tiwari, Garrett Cole, Marlene Velazco Medel, Amory Lowe, Jordan Monroe, Sara Sarbaz, Nick Lowery, Joel Eliston, Heidi P. Feigenbaum, Heather Emady, Jason C. Quinn, Matthew Green, John McGowen, Klaus Lackner, Wim Vermaas
A moisture-driven air capture system was developed and demonstrated for cultivating cyanobacteria and microalgae at the flask (50 mL), bench (12 L) and small pilot (840 L) scale. Purolite A501 anion exchange resin beads were found to be biocompatible and rapidly deliver air-captured CO2 when immersed directly in an alkaline cultivation medium containing cyanobacteria or microalgae. Flask-scale cultivation trials showed A501 could sustain rapid growth (190 mg/L/d) of the cyanobacterium Synechocystis sp. PCC 6803 strain engineered to produce laurate. A bench-scale system installed in a laminar flow hood was able to deliver 2 g CO2/d into abiotic alkaline cultivation medium and 0.5 g/d in the presence of Synechocystis to support vigorous growth (39 mg/L/d) limited by the CO2 delivered by the sorbent. A small pilot-scale system installed in a 4.2 m2 outdoor raceway pond in Mesa, Arizona was able to deliver 100 g CO2/d into abiotic alkaline cultivation medium. Exopolysaccharides and other products excreted by Synechocystis 6803 covered the sorbent beads, reducing their capacity to 25%, which could be partially restored to 70% capacity using a wash protocol, but the CO2 delivery kinetics remained 3-4 fold slower. Analysis of the sorbent beads used as part of four separate outdoor cultivation trials with over 300 days of outdoor wet and dry cycling over four seasons showed significant mechanical fracturing. Infrared spectroscopy and thermogravimetric analysis showed a significant loss of NR4+ functional groups necessary for CO2 capture correlated with extended use. Under the assumption that abiotic performance eventually can be retained by delivering CO2 into the media recycle stream in a way that avoids biofouling, technoeconomic and life cycle analyses show the viability of a small first-of-a-kind biorefinery producing 500 barrels per day of biofuel.
Soft Condensed Matter (cond-mat.soft), Other Condensed Matter (cond-mat.other)
18 pages, 13 main figures
Using Topology to Predict Electrides in the Solid State
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Electrides are characterized by electron density highly localized in interstitial sites, which do not coincide with the interatomic contacts. The rigorous quantum mechanical definition of electrides is based upon topological criteria derived from the electron density, and in particular the presence of non-nuclear attractors (NNAs). We employ these topological criteria in combination with crystal structure prediction methods (the XtalOpt evolutionary algorithm), to accelerate the discovery of crystalline electrides at ambient and non-ambient pressures. The localization and quantification of NNAs is used as the primary discriminator for the electride character of a solid within a multi-objective evolutionary structure search. We demonstrate the reliability of this approach through a comprehensive crystal structure prediction study of Ca5Pb3 at 20 GPa, a system previously theorized to exhibit electride character under compression. Our strategy could predict, and sort on-the-fly, several unknown low-enthalpy phases that possess NNAs in interstitial loci, such as the newly discovered P4/mmm structure. These results demonstrate how evolutionary algorithms, guided by rigorous topological descriptors, can be relied upon to effectively survey complex phases to find new electride candidates.
Materials Science (cond-mat.mtrl-sci)
Intertwined Electron pairing in the Bilayer Two-orbital Kanamori-Hubbard Model: a Unified Picture of Two Superconductivities in $\mathrm{La_3Ni_2O_7}$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-07 20:00 EDT
Shicong Mo, Yaoyuan Zheng, Wei Wu
The mechanism of pairing in $ \mathrm{La_3Ni_2O_7}$ bulk and film superconductors remains actively debated. Here, we investigate the bilayer two-orbital Kanamori-Hubbard model for $ \mathrm{La_3Ni_2O_7}$ using cellular dynamical mean-field theory. We find two intertwined $ s_{\pm}$ -wave superconductivities with distinct physical origins under enhanced Hund’s coupling $ J_H$ . We show that when $ d_{z^2}$ orbital is half-filled and its bonding band lies below Fermi level, electron pairing associated to $ J_H$ prevails. As $ d_{z^2}$ orbital is hole-doped, this superconducting state becomes suppressed and a second superconductivity, which is largely insensitive to $ J_H$ but exhibiting a critical reliance on $ d_{z^2}$ - $ d_{x^2-y^2}$ hybridization $ V$ , arises. These two pairing states exhibit comparable maximum transition temperatures and evolve continuously from one to the other with varying $ d_{z^2}$ doping, resulting a smooth $ T_c$ versus doping evolution. The dependence on various physical parameters of the two superconductivities is studied. Our results present a unified picture reconciling the debate about the role of $ d_{z^2}$ orbital in pairing. We discuss the relevance of our results to recent experiments on superconducting $ \mathrm{La_3Ni_2O_7}$ films.
Superconductivity (cond-mat.supr-con)
6 pages, 5 figures
Quantum and classical Shapiro steps in small Josephson junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-07 20:00 EDT
Miriam Resch, Joachim Ankerhold, Brecht I. C. Donvil, Paolo Muratore-Ginanneschi, Dmitry Golubev
We propose a model describing the formation of both dual (quantum) and classical Shapiro steps in small Josephson junctions. According to this model, the dual Shapiro steps are formed at relatively low frequency of the microwave signal and low microwave power, while the classical steps are formed in the opposite limit of high frequency and power. The crossover between the two regimes is controlled by a single parameter - the effective relaxation time of the environment. The model accounts for the effect of a large inductor in the bias circuit, which has been used in recent experiments to protect the junction from the high frequency noise of the environment. We predict the possibility of observing both types of steps in the same sample. Our model describes the I-V curves observed in the experiments with reasonable accuracy, thus opening up an opportunity for quantitative fitting of the data.
Superconductivity (cond-mat.supr-con)
12 pages, 9 figures
Unveiling quantum criticality of disordered Aubry-André-Harper models via typical fidelity susceptibility
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-08-07 20:00 EDT
Tian-Cheng Yi, Ying-Ying Fang, Wen Chen, Wen-Long You, Yunbo Zhang
In this study, we investigate the localization transition and quantum criticality {in the ground state of the} disordered Aubry-André-Harper (AAH) model, where a quasiperiodic potential is hybridized with a disordered potential. In the clean limit, the AAH model undergoes a localization transition from an extended phase to a localized phase via an intermediate critical phase as the strength of the quasiperiodic potential is varied. While the staggered potential merely shifts the critical point to a lower value, Fibonacci and Thue-Morse potentials induce immediate localization. This contrast reveals the sensitivity of localization behavior to the structural complexity of the potential, with the onset of localization correlating with the sequence’s complexity. More specifically, the system follows a hierarchy defined by the complexity measures of the applied potentials. In addition, the typical fidelity susceptibility exhibits a power-law scaling behavior at the localization transition, enabling reliable extraction of the critical exponent. We focus on the AAH model with the Fibonacci potential due to its minimal finite-size effects compared to other cases. For the disordered AAH model with the Fibonacci potential, we determine critical exponents that differ from those of the AAH model without disorder and the Anderson model. Moreover, despite differences in localization behavior, we find that the disordered AAH models with the staggered potential and the Fibonacci potential share the same correlation-length critical exponent. These findings provide a unified framework for understanding localization transitions in quasiperiodic systems and are amenable to experimental validation using emerging techniques.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
8 pages, 7 figures
Phys. Rev. A 112, 023308 (2025)
Growth of few-layer molecular crystals of PTCDI on hexagonal boron nitride by microspacing air-gap sublimation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Nils LeCoutre, Tolibjon Abdurakhmonov, Paul Weinbrenner, Kenji Watanabe, Takashi Taniguchi, Tobias Korn, Franziska Fennel, Oliver Kühn, Friedemann Reinhard
Extended two-dimensional (2D) crystals of dye molecules adsorbed on 2D material substrates like boron nitride have recently become a subject of intense study, with potential applications ranging from quantum technology to optoelectronics. The most established technique for the production of these films is physical vapor transport in vacuum. We demonstrate that few-layer crystalline films of the organic dye molecule PTCDI on boron nitride can be produced by microspacing in-air sublimation, a radically simplified technique, not requiring complicated vacuum systems. The resulting layers display clearly resolved atomic step terraces in atomic force microscopy, and a clear polarization anisotropy in their fluorescence, confirming molecular alignment and long-range order. Using density functional theory and classical molecular dynamics simulations, the canted motive is identified as the most likely building block for the morphology of a PTDCI monolayer on the hBN substrate.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
ACS Applied Optical Materials 3, 455 (2025)
A unified model for linear responses of physical networks
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-07 20:00 EDT
José M. Ortiz-Tavárez, William Stephenson, Xiaoming Mao
Many physical systems–from mechanical lattices and electrical circuits to biological tissues and architected metamaterials–can be understood as networks transmitting physical quantities. We present a unified mathematical framework for describing linear responses of such physical networks using tools from algebraic graph theory. This approach captures static and dynamic behaviors across multiple domains, including mechanical, electrical, thermal, and diffusive responses using node and edge variables (e.g., potentials, flows). Our formalism connects multiscale and multi-domain responses to the underlying network structure. We demonstrate how this framework enables efficient, generalizable solutions to a wide class of linear response problems, including stress propagation, charge transport, and wave dynamics, and provide insights into network duality and entropy production.
Soft Condensed Matter (cond-mat.soft)
27 pages, 20 figures
Light induced transitions of valley Chern numbers and flat bands in a non-twisted moire graphene-hexagonal boron nitride superlattice
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-07 20:00 EDT
Saud Alabdulal, Miftah Hadi Syahputra Anfa, Hocine Bahlouli, Michael Vogl
Motivated by the rich topology and interesting quasi-band structure of twisted moire materials subjected to light, we study a non-twisted moire material under the influence of light. Our work is in part motivated by a desire to find an easier-to-synthesize platform that can help experimentally elucidate the interesting physics of moiré materials coupled to light. Similar to twisted moire materials, we uncover rich topology and interesting band flattening effects, which we summarize in relevant plots such as a topological phase diagram. Our work demonstrates that much of the interesting phenomenology of twisted moire materials under the influence of electromagnetic waves seems to be generically present even in more experimentally accessible untwisted moire platforms, which remain highly tunable by light.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Simulations of dielectric permittivity of water by Machine Learned Potentials with long-range Coulombic interactions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Kehan Cai, Chunyi Zhang, Xifan Wu
The dielectric permittivity of liquid water is a fundamental property that underlies its distinctive behaviors in numerious physical, biological, and chemical processes. Within a machine learning framework, we present a unified approach to compute the dielectric permittivity of water, systematically incorporating various electric boundary conditions. Our method employs a long-range-inclusive deep potential trained on data from hybrid density functional theory calculations. Dielectric response is evaluated using an auxiliary deep neural network that predicts the centers of maximally localized Wannier functions. We investigate three types of electric boundary conditions–metallic, insulating, and Kirkwood-Frohlich–to assess their influence on correlated dipole fluctuations and dielectric relaxation dynamics. In particular, we demonstrate a consistent methodology for computing the Kirkwood correlation factor, correlation length, and dielectric permittivity under each boundary condition, where long-range electrostatics play a critical role. This work establishes a robust and generalizable machine-learning framework for modeling the dielectric properties of polar liquids under diverse electrostatic environments.
Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech), Computational Physics (physics.comp-ph)
11 pages, 5 figures
Stochastic Calculus for Pathwise Observables of Markov-Jump Processes: Unification of Diffusion and Jump Dynamics
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-07 20:00 EDT
Lars Torbjørn Stutzer, Cai Dieball, Aljaž Godec
Path-wise observables–functionals of stochastic trajectories–are at the heart of time-average statistical mechanics and are central to thermodynamic inequalities such as uncertainty relations, speed limits, and correlation-bounds. They provide a means of thermodynamic inference in the typical situation, when not all dissipative degrees of freedom in a system are experimentally accessible. So far, theories focusing on path-wise observables have been developing in two major directions, diffusion processes and Markov-jump dynamics, in a virtually disjoint manner. Moreover, even the respective results for diffusion and jump dynamics were derived with a patchwork of different approaches that are predominantly indirect. Stochastic calculus was recently shown to provide a direct approach to path-wise observables of diffusion processes, while a corresponding framework for jump dynamics remained elusive. In our work we develop, in an exact parallelism with continuous-space diffusion, a complete stochastic calculus for path-wise observables of Markov-jump processes. We formulate a “Langevin equation” for jump processes, define general path-wise observables, and establish their covariation structure, whereby we fully account for transients and time-inhomogeneous dynamics. We prove the known kinds of thermodynamic inequalities in their most general form and discus saturation conditions. We determine the response of path-wise observables to general (incl. thermal) perturbations and carry out the continuum limit to achieve the complete unification of diffusion and jump dynamics. Our results open new avenues in the direction of discrete-state analogs of generative diffusion models and the learning of stochastic thermodynamics from fluctuating trajectories.
Statistical Mechanics (cond-mat.stat-mech), Probability (math.PR)
Tailored Thermal and Mechanical Performance of Biodegradable PLA-P(VDF-TrFE) Polymer Blends
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
G Suresh, B. Satyanarayana, C. Thirmal, Kaushal Jagarlamudi, T Komala, Jimlee Patowary, Ashutosh Kumar
The development of polymer blends has emerged as a strategic approach for designing multifunctional materials with enhanced tailored characteristics. Current work investigates and reports for the first time, the structure-property relationships in free-standing blend films of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) and polylactic acid (PLA), prepared to evaluate their suitability for functional applications. For this investigation, films of approximately 40 $ \mu$ m thick were fabricated by systematically varying the P(VDF-TrFE):PLA ratio. Thermal analysis revealed a higher PLA crystallinity at 25% P(VDF-TrFE) content, while Fourier-transform infrared spectroscopy showed the electroactive $ \beta$ -phase fraction to be highest in the 50:50 composition. These findings correlated with tensile strength measurements and morphology, demonstrating that molecular ordering and phase distribution significantly influence the mechanical performance. The 25:75 blend exhibited superior mechanical strength due to enhanced PLA crystallization and polymer chain alignment. In contrast, the 50:50 blend achieved a balance between tensile modulus and electroactive phase development, marking it a promising candidate for sensors and 3D printing applications. At higher P(VDF-TrFE) content, reduced crystallinity in PLA resulted in softer, more compliant films which would be suitable for flexible electronic applications. These results establish a pathway to tune mechanical and functional properties in semicrystalline polymer blends through facile compositional control.
Materials Science (cond-mat.mtrl-sci)
11 pages, 7 figures, 5 tables
Diffusion in a $d$-dimensional rough potential
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Jacob Jeffries, Emilio Mendoza Reyes, Fadi Abdeljawad, Murray Daw, Enrique Martinez
The prediction of diffusion in solids is necessary to understand the microstructure evolution in materials out of equilibrium. Although one can reasonably predict diffusive transport coefficients using atomistic methods, these approaches can be very computationally expensive. In this work, we develop an analytical model for the diffusivity in a noisy solid solution in an arbitrary number of dimensions using a mean first passage time analysis. These analytical results are then compared with kinetic Monte Carlo (KMC) simulations, which are in good agreement with the simulation data in the low-noise limit. We argue that the difference is expected from percolation pathways that increase the diffusivity in the KMC analysis but are not captured by the model. This generalization to arbitrary dimensions has been elusive to the community since Zwanzig [PNAS, 85, 2029 (1988)] published his seminal work on 1-dimensional systems.
Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
9 pages, 4 figures
A colossal dielectric response of HfxZr1-xO2 nanoparticles
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-07 20:00 EDT
Oleksandr S. Pylypchuk, Victor V. Vainberg, Vladimir N. Poroshin, Oksana V. Leshchenko, Victor N. Pavlikov, Irina V. Kondakova, Serhii E. Ivanchenko, Lesya P. Yurchenko, Lesya Demchenko, Anna O. Diachenko, Myroslav V. Karpets, Mikhail P. Trubitsyn, Eugene A. Eliseev, Anna N. Morozovska
We reveal a colossal dielectric response of small (5 - 10 nm) oxygen-deficient HfxZr1-xO2 nanoparticles (x = 1 - 0.4), prepared by the solid-state organonitrate synthesis. The effective dielectric permittivity of the pressed HfxZr1-xO2 nanopowders has a pronounced maximum at 38 - 88 C, which shape can be fitted by the Curie-Weiss type dependence modified for the diffuse ferroelectric-paraelectric phase transition. The maximal value of the dielectric permittivity increases from 1.5\ast10^3 (for x = 1) to 1.5\ast10^5 (for x= 0.4) at low frequencies (4 Hz); being much smaller, namely changing from 7 (for x = 1) to 20 (for x = 0.4) at high frequencies (500 kHz). The frequency dispersion of the dielectric permittivity maximum position is almost absent, meanwhile the shape and width of the maximum changes in a complex way with increase in frequency. The temperature dependencies of the dielectric permittivity and resistivity are almost mirror-like turned over in respect to each other, which means that all their features, such as position and shape of maxima, plateau, minima and inflexions, almost coincide after the mirror reflection in respect to the temperature axis. These correlations of resistivity and dielectric permittivity are well-described in the Heywang barrier model applied together with the variable range hopping conduction model in semiconducting ferroelectrics. The ferroelectric-like behavior of the dielectric permittivity is explained by the Landau-Ginzburg-Devonshire approach and density functional theory calculations, which reveal that small HfxZr1-xO2 nanoparticles can become ferroelectric in the presence of oxygen vacancies. Obtained results may be useful for developing silicon-compatible ferroelectric nanomaterials based on HfxZr1-xO2 nanoparticles.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
40 pages, including 10 figures and Supporting Information