CMP Journal 2025-09-05
Statistics
Nature Materials: 2
Nature Nanotechnology: 1
Nature Physics: 1
Physical Review Letters: 14
Physical Review X: 1
Review of Modern Physics: 1
arXiv: 89
Nature Materials
Local photocrosslinking of native tissue matrix regulates lung epithelial cell mechanosensing and function
Original Paper | Stem-cell differentiation | 2025-09-04 20:00 EDT
Donia W. Ahmed, Matthew L. Tan, Yuchen Liu, Jackson Gabbard, Esther Gao, Avinava Roy, Michael M. Hu, Firaol S. Midekssa, Miriam Stevens, Fulei Wuchu, Minal Nenwani, Jingyi Xia, Adam Abraham, Deepak Nagrath, Lin Han, Rachel L. Zemans, Brendon M. Baker, Claudia Loebel
Within most tissues, the extracellular microenvironment provides mechanical cues that guide cell fate and function. Changes in the extracellular matrix such as aberrant deposition, densification and increased crosslinking are hallmarks of late-stage fibrotic diseases that often lead to organ dysfunction. Biomaterials have been widely used to mimic the mechanical properties of the fibrotic matrix and study pathophysiologic cell function. However, the initiation of fibrosis has largely been overlooked, due to challenges in recapitulating early stages of disease progression within the native extracellular microenvironment. Here, using visible-light-mediated photochemistry, we induced local crosslinking and stiffening of extracellular matrix proteins within ex vivo mouse and human lung tissue. In ex vivo lung tissue of epithelial cell lineage-traced mice, local matrix crosslinking mimicked early fibrotic lesions that increased alveolar epithelial cell mechanosensing, differentiation, and nascent protein deposition and remodelling. However, the inhibition of cytoskeletal tension, mechanosensitive signalling pathways or integrin engagement reduced epithelial cell spreading and differentiation. Our findings emphasize the role of local extracellular matrix crosslinking and nascent protein deposition in early stage tissue fibrosis and have implications for ex vivo disease modelling and applications to other tissues.
Stem-cell differentiation, Tissues
Magnetically actuated multimodal bioelectronic catheter for minimally invasive surgery and sensing
Original Paper | Biomedical engineering | 2025-09-04 20:00 EDT
Jingbo Yang, Yuanxi Zhang, Zhengjie Liu, Shuang Huang, Xinshuo Huang, Yunuo Wang, Mingqiang Li, Shantao Zheng, Fuqian Chen, Jing Liu, Yu Tao, Tong Wu, Lizhi Xu, Huijiuan Chen, Lelun Jiang, Xi Xie
Small-scale magnetically actuated catheters capable of remote active navigation have promising applications in minimally invasive surgeries. However, existing fabrication techniques hinder their integration with multimodal sensing components, especially since embedding rigid electronic components within the catheters may diminish their flexibility and controllability. Here we report a magnetically actuated bioelectronic catheter with the in situ multiplexed biosensing of multiple types of metabolite or ion simultaneously. We use four-dimensional multichannel printing to fabricate a flexible multichannel ferromagnetic catheter with a multichannel-sheath structure, comprising six liquid metal microchannels embedded in a polymer matrix for electrical conduction. The catheter can navigate through blood vessels and intestines using magnetically controlled active steering, being used for renal vein or intestines interventional surgeries and in situ multimetabolite sensing on rabbit and porcine models. Overall, the reported magnetically actuated bioelectronic catheter is a promising tool for remotely controlled biosensing and therapies on hard-to-reach lesions during minimally invasive surgery.
Biomedical engineering, Sensors and biosensors
Nature Nanotechnology
Towards Floquet Chern insulators of light
Original Paper | Nonlinear optics | 2025-09-04 20:00 EDT
Jicheng Jin, Li He, Jian Lu, Lin Chang, Chen Shang, John E. Bowers, Eugene J. Mele, Bo Zhen
Topological photonics explores photonic systems that exhibit robustness against defects and disorder, enabled by protection from underlying topological phases. These phases are typically realized in linear optical systems and characterized by their intrinsic photonic band structures. Here we experimentally study Floquet Chern insulators in periodically driven nonlinear photonic crystals, where the topological phase is controlled by the polarization and the frequency of the driving field. Our transient sum-frequency generation measurements reveal strong hybridization of the Floquet photonic bands. The measured spectrum remains gapless under a linearly polarized drive but becomes gapped under a circularly polarized drive. Theoretical analysis confirms that the Floquet gap is topological, characterized by a non-zero Chern number–a consequence of time-reversal symmetry breaking induced by the circularly polarized driving field. This work offers opportunities to explore the role of classical optical nonlinearity in topological phases and their applications in nonlinear optoelectronics.
Nonlinear optics, Photonic crystals
Nature Physics
Pressure induced superconductivity in hybrid Ruddlesden‒Popper La5Ni3O11 single crystals
Original Paper | Superconducting properties and materials | 2025-09-04 20:00 EDT
Mengzhu Shi, Di Peng, Kaibao Fan, Zhenfang Xing, Shaohua Yang, Yuzhu Wang, Houpu Li, Rongqi Wu, Mei Du, Binghui Ge, Zhidan Zeng, Qiaoshi Zeng, Jianjun Ying, Tao Wu, Xianhui Chen
The discovery of high-temperature superconductivity under high pressure in Ruddlesden-Popper phase nickelates has captured notable attention in the condensed matter physics community. Here we report superconductivity in a distinct hybrid nickelate, La5Ni3O11, formed by alternating stacks of La3Ni2O7 and La2NiO4 layers. This nickelate also exhibits a density-wave transition at approximately 170 K near ambient pressure. With increasing pressure, this density-wave transition shifts to higher temperatures and abruptly disappears around 12 GPa, followed by the emergence of superconductivity, indicating a first-order phase transition. But the optimal superconductivity with large superconducting volume fraction is observed at approximately 21 GPa with ({T}_{ {\rm{c}}}^{ {;\rm{zero}}}) = 54 K. High-pressure X-ray diffraction experiments reveal a structural phase transition from an orthorhombic structure to a tetragonal structure at lower pressure. Notably, this structural change has minimal impact on the density-wave or superconducting phases, suggesting a limited role of lattice degrees of freedom in this material. These findings establish La5Ni3O11 as a new superconducting member of the Ruddlesden-Popper nickelate family and offer valuable insights into the interplay between structure, electronic order and superconductivity in hybrid nickelates.
Superconducting properties and materials
Physical Review Letters
Measurement Incompatibility under Loss
Research article | Quantum communication, protocols & technology | 2025-09-04 06:00 EDT
Mohammad Mehboudi, Fatemeh Rezaeinia, and Saleh Rahimi-Keshari
We investigate the measurement incompatibility of continuous-variable systems with infinite-dimensional Hilbert spaces under the influence of pure losses, a fundamental noise source in quantum optics, and a significant challenge for long-distance quantum communication. We show that loss channels with transmissivities less than $1/n$ make any set of $n$ measurements compatible. Additionally, we design a set of measurements that remains incompatible even under extreme losses, where the number of measurements in the set increases with the amount of loss. These measurements rely on on-off photodetectors and linear optics, making them feasible for implementation under realistic laboratory conditions. Furthermore, we demonstrate that no loss channel can break the incompatibility of all measurements. As a result, quantum steering remains achievable in the presence of pure loss.
Phys. Rev. Lett. 135, 100202 (2025)
Quantum communication, protocols & technology, Quantum harmonic oscillator, Quantum measurements
Quantum Metrology in the Ultrastrong Coupling Regime of Light-Matter Interactions: Leveraging Virtual Excitations without Extracting Them
Research article | Cavity quantum electrodynamics | 2025-09-04 06:00 EDT
Christoph Hotter, Adam Miranowicz, and Karol Gietka
Virtual excitations, inherent to ultrastrongly coupled light-matter systems, induce measurable modifications in system properties, offering a novel resource for quantum technologies. In this Letter, we demonstrate how these virtual excitations and their correlations can be harnessed to enhance precision measurements, without the need to extract them. Building on the paradigmatic Dicke model, which describes the interaction between an ensemble of two-level atoms and a single radiation mode, we propose a method to harness hybridized light-matter modes whose renormalized frequencies encode the effects of virtual excitations for quantum metrology. Remarkably, we find that, for a fixed squeezing parameter $\xi $, exploiting virtual squeezing through oscillator frequency shifts yields a quadratic enhancement in estimation precision—scaling as $\mathrm{exp}(4\xi )$—compared to the conventional $\mathrm{exp}(2\xi )$ scaling of real squeezed states. These results show that virtual excitations, though unobservable, can drive metrological performance beyond the standard quantum limit. Our approach establishes a broadly applicable framework for high-precision measurements across a wide class of ultrastrongly coupled quantum systems.
Phys. Rev. Lett. 135, 100802 (2025)
Cavity quantum electrodynamics, Light-matter interaction, Quantum metrology, Quantum phase transitions
Elliptic Leading Singularities and Canonical Integrands
Feynman diagrams | 2025-09-04 06:00 EDT
E. Chaubey and V. Sotnikov
In the well-studied genus zero case, bases of d log integrands with integer leading singularities define Feynman integrals that automatically satisfy differential equations in canonical form. Such integrand bases can be constructed without input from the differential equations and without explicit involvement of dimensional regularization parameter $\epsilon $. We propose a generalization of this construction to genus one geometry arising from the appearance of elliptic curves. We argue that a particular choice of algebraic 1-forms of the second kind that avoids derivatives is crucial. We observe that the corresponding Feynman integrals satisfy a special form of differential equations that has not been previously reported, and that their solutions order by order in $\epsilon $ yield pure functions. We conjecture that our integrand-level construction universally leads to such differential equations.
Phys. Rev. Lett. 135, 101903 (2025)
Feynman diagrams, Particle interactions, Perturbation theory, Differential equations
Dilepton Production from Moaton Quasiparticles
Research article | Lepton production | 2025-09-04 06:00 EDT
Zohar Nussinov, Michael C. Ogilvie, Laurin Pannullo, Robert D. Pisarski, Fabian Rennecke, Stella T. Schindler, and Marc Winstel
The phase diagram of QCD probably exhibits a moat regime over a large region of temperature $T$ and chemical potential $\mu \ne 0$. A moat regime is characterized by quasiparticle moatons (pions) whose energy is minimal at nonzero spatial momentum. At $\mu \ne 0$, higher mass dimension operators play a critical role in a moat regime. At dimension six, there are nine possible gauge-invariant couplings between scalars and photons. For back-to-back dilepton production, only one operator contributes, which significantly enhances production near a moat threshold. This enhancement is an experimental signature of moatons.
Phys. Rev. Lett. 135, 101904 (2025)
Lepton production, Particle production, QCD phase transitions, Strong interaction
Pressure-Induced Polyhedral Reorganization Causes Indirect-to-Direct Band-Gap Transition in Spinel Structure
Research article | Pressure effects | 2025-09-04 06:00 EDT
Pengfei Shen, Donghao Xu, Zhiguo Xia, and Mingguang Yao
Spinel oxides (${\mathrm{AB}}{2}{\mathrm{O}}{4}$) are promising optoelectronic materials due to their structural stability and tunable electronic properties. However, conventional strategies like doping, element substitution, and thermal treatment have achieved limited success in optimizing their performance. Here, we demonstrate that pressure-induced polyhedral reorganization triggers an indirect-to-direct band-gap transition driven by the enhanced hybridization of $\mathrm{O}\text{- }{p}{y}$ orbitals in ${\mathrm{AB}}{2}{\mathrm{O}}{4}$ systems. The pressure-induced polyhedral reorganization also causes a connectivity shift from corner-sharing tetrahedra (${\mathrm{GaO}}{4}$) to edge-sharing octahedra (${\mathrm{GaO}}{6}$) in single-phase ${\mathrm{CaGa}}{2}{\mathrm{O}}{4}:{\mathrm{Bi}}^{3+}$ crystals, which tailors the electronic redistribution from isolated to quasi-1D ladderlike configurations. The optimized electronic structure leads to a concurrent enhancement in the photoresponsivity by $\sim 200%$ and the emergence of an exotic white-light emission, which can be quenched to ambient conditions. These findings reveal how ${\mathrm{GaO}}{\mathrm{x}}$ polyhedral reorganization directly governs electronic evolution in ${\mathrm{CaGa}}{2}{\mathrm{O}}{4}:{\mathrm{Bi}}^{3+}$, providing a new pathway to tailor electronic structures and optoelectronic properties through pressure-driven design that bypasses the limitations of traditional approaches.
Phys. Rev. Lett. 135, 106102 (2025)
Pressure effects, Structural properties, Electronic structure, Density functional theory, Pressure techniques, Raman spectroscopy
Singlet-Only Always-On Gapless Exchange Qubits with Baseband Control
Research article | Exchange interaction | 2025-09-04 06:00 EDT
Nathan L. Foulk, Silas Hoffman, Katharina Laubscher, and Sankar Das Sarma
We propose a singlet-only always-on gapless exchange (SAGE) spin qubit that encodes a single qubit in the spins of four electrons while allowing universal baseband control. While conventional exchange-only qubits suffer from magnetic-field-gradient-induced leakage and coherent errors due to local nuclear environments and variations in the $g$-factor, the SAGE qubit subspace is protected from coherent errors due to local magnetic field gradients, and leakage out of the computational subspace is energetically suppressed due to the exchange interactions between electrons being always on. Consequently, we find that when magnetic gradient noise dominates over charge noise, coherence times and single-qubit gate infidelities of the SAGE qubit improve by an order of magnitude compared to conventional exchange-only qubits. Moreover, using realistic parameters, two-qubit gates can be performed with a single interqubit exchange pulse with times comparable in duration to conventional exchange-only qubits but with a significantly simplified pulse sequence.
Phys. Rev. Lett. 135, 106202 (2025)
Exchange interaction, Quantum gates, Quantum information with solid state qubits, Qubits, Spin blockade, Quantum dots, Exact diagonalization, Perturbation theory
Probing Green’s Function Zeros by Cotunneling through Mott Insulators
Research article | Coulomb blockade | 2025-09-04 06:00 EDT
Carl Lehmann, Lorenzo Crippa, Giorgio Sangiovanni, and Jan Carl Budich
Quantum tunneling experiments have provided deep insights into basic excitations occurring as Green’s function poles in the realm of complex quantum matter. However, strongly correlated quantum materials also allow for Green’s functions zeros (GFZs) that may be seen as an antidote to the familiar poles and have so far largely eluded direct experimental study. Here, we propose and investigate theoretically how cotunneling through Mott insulators enables direct access to the shadow band structure of GFZs. In particular, we derive an effective Hamiltonian for the GFZ that is shown to govern the cotunneling amplitude and reveal fingerprints of many-body correlations clearly distinguishing the GFZ structure from the underlying free Bloch band structure of the system. Our perturbative analytical results are corroborated by numerical data in the framework of both exact diagonalization and matrix product state simulations for a one-dimensional model system consisting of a Su-Schrieffer-Heeger-Hubbard model coupled to two single-level quantum dots.
Phys. Rev. Lett. 135, 106303 (2025)
Coulomb blockade, Geometric & topological phases, Mesoscopics, Quantum simulation, Transport phenomena, Mott insulators, Quantum dots, Su-Schrieffer-Heeger model
Terahertz Field Control of Electronic-Ferroelectric Anisotropy at Room Temperature in ${\mathrm{LuFe}}{2}{\mathrm{O}}{4}$
Research article | Charge order | 2025-09-04 06:00 EDT
Hirotake Itoh, Ryusei Minakami, Hongwu Yu, Ryohei Tsuruoka, Tatsuya Amano, Yohei Kawakami, Shin-ya Koshihara, Kosuke Fujiwara, Naoshi Ikeda, Yoichi Okimoto, and Shinichiro Iwai
Electronic ferroelectrics, with polarization $\mathbit{P}$ induced by strongly correlated charges, are expected to show ultrafast, huge, and flexible responses required in future optoelectronics. Although the challenges for ultrafast manipulation of such a polarization are ongoing, the expected advantages have been unclear. In this Letter, we demonstrate an unprecedentedly large increase by a factor of 2.7 in optical second harmonic generation at room temperature in the prototypical electronic ferroelectrics, the rare-earth ferrite ${\mathrm{LuFe}}{2}{\mathrm{O}}{4}$, by applying a terahertz field of $260\text{ }\text{ }\mathrm{kV}/\mathrm{cm}$. The transient anisotropy indicates that the direction of macroscopic polarization can be controlled three dimensionally on subpicosecond timescales, offering additional degrees of freedom in controlling polarization. Although the polarization response is in phase concerning the terahertz field, its sensitivity increased with delay, indicating that cooperative interactions among microscopic domains play an important role in the unprecedented response.
Phys. Rev. Lett. 135, 106504 (2025)
Charge order, Ferroelectricity, Ferroelectrics, Strongly correlated systems, Terahertz techniques, Time-resolved infrared spectroscopy
Non-Abelian Fractional Chern Insulators and Competing States in Flat Moir'e Bands
Research article | Exotic phases of matter | 2025-09-04 06:00 EDT
Hui Liu, Zhao Liu, and Emil J. Bergholtz
By tuning the coupling strength between twisted bilayers in a moiré material, transitioning the flat band from the regime of the lowest Landau level to the second Landau level, phase transitions occur between gapless composite Fermi liquids, charge density waves, and genuine Moore-Read states.
Phys. Rev. Lett. 135, 106604 (2025)
Exotic phases of matter, Fractional quantum Hall effect, Topological materials, Topological order
Extrinsic Mechanisms of Phonon Magnetic Moment
Research article | Electron-phonon coupling | 2025-09-04 06:00 EDT
Rui Xue, Zhenhua Qiao, Yang Gao, and Qian Niu
We develop a general formalism of the phonon magnetic moment by including the relaxation processes. We then identify the skew-scattering and side-jump contributions to the phonon magnetic moment originating from the nonadiabaticity, both of which are related to the nonlocal phonon Berry curvature and are in close analogy to those in the electronic Hall effect. All contributions of the phonon magnetic moment are exemplified in a honeycomb lattice, showing that the extrinsic contribution can be as important as the intrinsic one and that the resulting phonon angular momentum varies significantly across the Brillouin zone. Our Letter offers a systematic framework of the phonon chirality and paves the way for tuning the phonon magnetic moment through the nonadiabaticity.
Phys. Rev. Lett. 135, 106605 (2025)
Electron-phonon coupling, Magnetism, Phonons, Topological phases of matter, Magnetic moment
Hydrodynamics of Cooperation and Self-Interest in a Two-Population Occupation Model
Research article | Phase transitions | 2025-09-04 06:00 EDT
Jérôme Garnier-Brun, Ruben Zakine, and Michael Benzaquen
Socioeconomic systems, where individualistic and altruistic agents coexist and interact, can be analytically characterized through state-of-the-art tools from active matter at the hydrodynamics scale.
Phys. Rev. Lett. 135, 107402 (2025)
Phase transitions, Social dynamics, Mean field theory, Theories of collective dynamics & active matter
Weak-Correlation Universality and Macroscopic Fluctuations in Power-Law Recurrent Networks
Research article | Biological neural networks | 2025-09-04 06:00 EDT
Farzada Farkhooi
Balanced network theory describes the dynamic state of randomly connected systems with intrinsic negative feedback, predicting the suppression of correlations as connectivity increases. We show that this weak-correlation universality holds broadly but breaks down in power-law networks where the largest out-degrees scale with system size. In such networks, residual correlations cross over to a regime that retains macroscopic fluctuations in the thermodynamic limit. Unlike Erd"os-R'enyi networks, the degree heterogeneity of power-law topologies amplifies coherent population-level fluctuations. Our results provide a theoretical foundation for the strong correlations observed in real-world networks with sparse and heterogeneous connectivity.
Phys. Rev. Lett. 135, 107403 (2025)
Biological neural networks, Network structure, Neuronal dynamics, Scaling laws of complex systems, Spiking neurons, Spin coherence, Biological networks, Cortical networks, Real world networks, Ising model, Markovian processes, Mean field theory
Deciphering Complexity in Human Brain Organoids via a Novel Hurst Exponent Estimation
Research article | Cellular organization, physiology & dynamics | 2025-09-04 06:00 EDT
Mariana Sacrini Ayres Ferraz, Alysson R. Muotri, and Alexandre Hiroaki Kihara
A method that estimates the Hurst exponent directly from a binary spike train series suggests that the coefficient of variation of the exponent, rather than the exponent itself, more accurately reflects neural complexity during organoid maturation.
Phys. Rev. Lett. 135, 108402 (2025)
Cellular organization, physiology & dynamics, Fluctuations & noise, Neuroscience, neural computation & artificial intelligence, Brownian dynamics, Information theory, Stochastic analysis methods
Erratum: Giant Splitting of the Hydrogen Rotational Eigenenergies in the ${\mathrm{C}}_{2}$ Filled Ice [Phys. Rev. Lett. 133, 236101 (2024)]
Correction | | 2025-09-04 06:00 EDT
Simone Di Cataldo, Maria Rescigno, Lorenzo Monacelli, Umbertoluca Ranieri, Richard Gaal, Stefan Klotz, Jacques Ollivier, Michael Marek Koza, Cristiano De Michele, and Livia Eleonora Bove
Phys. Rev. Lett. 135, 109902 (2025)
Physical Review X
Quantum Effects in Gravity Beyond the Newton Potential from a Delocalized Quantum Source
Research article | Experimental studies of gravity | 2025-09-04 06:00 EDT
Lin-Qing Chen and Flaminia Giacomini
New predictions from linearized quantum gravity show that delocalized sources and gravitational-field commutators could offer stronger evidence for future experiments that gravity is inherently quantum.
Phys. Rev. X 15, 031063 (2025)
Experimental studies of gravity, General relativity, Quantum field theory (low energy), Quantum foundations, Quantum gravity
Review of Modern Physics
Solar fusion III: New data and theory for hydrogen-burning stars
Research article | H & He burning | 2025-09-04 06:00 EDT
B. Acharya et al.
*et al.*Approximately 90% of the stars in the Milky Way are on the main sequence, fusing hydrogen into helium through a network of nuclear reactions. This includes the nearest star, our Sun. A precise understanding of hydrogen burning is crucial to predicting its luminosity, neutrino production, and helioseismology. This review describes the theoretical and experimental work of the last decade that has advanced our understanding of the nuclear physics of hydrogen burning. It describes the plasma and atomic physics that influences the solar environment in which the nuclear reactions take place, as well as the diagnostics probes–including solar neutrinos and helioseismology–that allow us to test our resulting model of the solar interior.
Rev. Mod. Phys. 97, 035002 (2025)
H & He burning, Hydrostatic stellar nucleosynthesis
arXiv
Escape over a saddle by coloured noise: theory and numerics
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-05 20:00 EDT
Jiayao Shao, Tobias Grafke, Robert S. MacKay
Stochastic dynamical systems allow modelling of transitions induced by disturbances, in particular from an attracting equilibrium and crossing the stable manifold of a saddle. In the small-noise limit, the probability of such transitions is governed by a large deviation principle. We illustrate a computational approach-the Method of Division-for approximating rare transition events, including their most likely paths, transition rates, and associated probabilities. To cater for realistic applications, we allow unbounded time, coloured and degenerate forcing. Its effectiveness is demonstrated on two examples: an inverted double-well potential and a simplified roll-heave ship capsize model.
Statistical Mechanics (cond-mat.stat-mech), Probability (math.PR)
An exact multiple-time-step variational formulation for the committor and the transition rate
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-05 20:00 EDT
Chatipat Lorpaiboon, Jonathan Weare, Aaron R. Dinner
For a transition between two stable states, the committor is the probability that the dynamics leads to one stable state before the other. It can be estimated from trajectory data by minimizing an expression for the transition rate that depends on a lag time. We show that an existing such expression is minimized by the exact committor only when the lag time is a single time step, resulting in a biased estimate in practical applications. We introduce an alternative expression that is minimized by the exact committor at any lag time. Numerical tests on benchmark systems demonstrate that our committor and resulting transition rate estimates are much less sensitive to the choice of lag time. We derive an additional expression for the transition rate, relate the transition rate expression to a variational approach for kinetic statistics based on the mean-squared residual, and discuss further numerical considerations with the aid of a decomposition of the error into dynamic modes.
Statistical Mechanics (cond-mat.stat-mech), Machine Learning (cs.LG), Computational Physics (physics.comp-ph), Data Analysis, Statistics and Probability (physics.data-an)
42 pages, 3 figures
From Qubits to Qumodes: Information Capacity of Anyonic Excitations
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
The interplay between quantum statistics and information encoding is a cornerstone of quantum physics. Here, the maximum information capacity of a quantum state governed by Haldane’s exclusion statistics is derived. The capacity, defined by the maximum von Neumann entropy of its occupancy distribution, follows S_max(g) = log2(\lfloor 1/g \rfloor + 1). This result continuously interpolates between the fermionic limit of a single qubit (g = 1) and the bosonic limit of a continuous-variable qumode (g -> 0). For the nu = 1/3 fractional quantum Hall state (g = 1/3), we predict a 2-bit capacity, observable as four distinct quantized conductance plateaus in quantum dot spectroscopy, providing a direct signature of anyonic statistics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 8 figures
Combining feature-based approaches with graph neural networks and symbolic regression for synergistic performance and interpretability
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Rogério Almeida Gouvêa, Pierre-Paul De Breuck, Tatiane Pretto, Gian-Marco Rignanese, Marcos José Leite dos Santos
This study introduces MatterVial, an innovative hybrid framework for feature-based machine learning in materials science. MatterVial expands the feature space by integrating latent representations from a diverse suite of pretrained graph neural network (GNN) models including: structure-based (MEGNet), composition-based (ROOST), and equivariant (ORB) graph networks, with computationally efficient, GNN-approximated descriptors and novel features from symbolic regression. Our approach combines the chemical transparency of traditional feature-based models with the predictive power of deep learning architectures. When augmenting the feature-based model MODNet on Matbench tasks, this method yields significant error reductions and elevates its performance to be competitive with, and in several cases superior to, state-of-the-art end-to-end GNNs, with accuracy increases exceeding 40% for multiple tasks. An integrated interpretability module, employing surrogate models and symbolic regression, decodes the latent GNN-derived descriptors into explicit, physically meaningful formulas. This unified framework advances materials informatics by providing a high-performance, transparent tool that aligns with the principles of explainable AI, paving the way for more targeted and autonomous materials discovery.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
Hydrogen storage in nanocrystalline high entropy material
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Yogesh Kumar Yadav, Mohammad Abu Shaz, Thakur Prasad Yadav
In this study, a single-phase nanocrystalline Al-Cu-Fe-Ni-Cr high-entropy alloy (HEA) has been synthesized by mechanical alloying and comprehensively investigated for hydrogen storage responses evaluated in details. High-energy attritor ball mill was used to synthesize the alloy from elemental powder, and hexane medium was used as a process control agent. As synthesized materials was nanocrystalline in nature after 40 h of milling with a lattice parameter of 0.289 nm body-centered cubic (BCC) phase. As synthesized nanocrystalline Al-Cu-Fe-Ni-Cr HEA demonstrated remarkable hydrogen storage properties, absorbing 2.1 wt.% of hydrogen in 3 minutes at 300°C with 50 atm of hydrogen pressure. At the same temperature, it also desorbed about 1.6 wt.% of hydrogen in 6 minutes. These quick rates of absorption and desorption demonstrate how well the alloy absorbs and releases hydrogen. Additionally, the alloy showed outstanding cyclic stability, retaining almost all of its hydrogen capacity across 25 cycles with only a slight 0.2 wt.% loss. The nanocrystalline Al-Cu-Fe-Ni-Cr HEA is a potential option for hydrogen storage applications due to its outstanding cycle stability and fast kinetics of hydrogen storage and release.
Materials Science (cond-mat.mtrl-sci)
22 pages, 9 Figures
Two-Body Contact Dynamics in a Bose Gas near a Fano-Feshbach Resonance
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-09-05 20:00 EDT
Alexandre Journeaux, Julie Veschambre, Maxime Lecomte, Ethan Uzan, Jean Dalibard, Félix Werner, Dmitry S. Petrov, Raphael Lopes
We investigate the real-time buildup of short-range correlations in a nondegenerate ultracold Bose gas near a narrow Fano-Feshbach resonance. Using rapid optical control, we quench the closed-channel molecular energy to resonance on sub-microsecond timescales and track the evolution of the two-body contact through photo-dissociation losses. Repeated pulse sequences enhance sensitivity to early-time two-body losses and reveal long-lived coherence between atom pairs and molecular states. The observed dynamics are accurately reproduced by our dynamical two-channel zero-range theory, which explicitly accounts for the resonance’s narrow width and finite closed-channel decay, establishing a predictive framework for correlation dynamics in quantum gases near Fano-Feshbach resonances.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
12 pages, 10 figures
Exchange tensors, generalized RKKY interactions, and magnetization dynamics in heterostructures of ferromagnets and topological insulators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Christian Svingen Johnsen, Asle Sudbø
We present a comprehensive theoretical analysis of magnetic heterostructures composed of ferromagnetic (FM) layers interfaced with three-dimensional topological insulators (TIs). Integrating out the topological surface states and computing the spin determinant to second order in spins, we derive the effective generalized Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange interactions mediated by topological surface states. These interactions inherently incorporate spin-momentum locking and anisotropic spin susceptibilities stemming from the Dirac-like dispersion of the TI surface electrons. The analysis reveals that the interplay between the spin-orbit coupling intrinsic to the TI and the magnetization texture in the FM layer induces highly nonlocal and retarded, chiral, and Dzyaloshinskii-Moriya (DM)-like contributions to the effective spin Hamiltonian. Furthermore, the spin dynamics is studied through a derivation of the LLG equation for this problem. The induced interactions renormalize many of the FM’s intrinsic properties, but a term in the LLG equation is induced that is related to the rate of change of the magnetization’s curl, which is relevant to skyrmion dynamics. The magnon dispersion exhibits modifications due to the TI-mediated interactions, including tunable magnon gaps, sensitive to a tunable chemical potential and interfacial exchange coupling strength. The results also apply to finite temperatures. They elucidate topologically induced magnetic phenomena and pave the way for engineering exotic spin textures, such as skyrmions and chiral domain walls, in TI/FM hybrid systems with tunable interactions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
19 pages, 2 figures
A new rung on the ladder: exploring topological frustration towards two dimensions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Alberto Giuseppe Catalano, Nora Reinić, Gianpaolo Torre, Sven Benjamin Kožić, Karlo Delić, Simone Montangero, Fabio Franchini, Salvatore Marco Gianpaolo
Topological frustration arises when boundary conditions impose geometric frustration in a quantum system, creating delocalized defects in the ground states and profoundly altering the low-energy properties. While previous studies have been concerned with one-dimensional systems, showing that the ground state structure can be described in terms of quasiparticle excitations, the two-dimensional setting remains unexplored. We address this gap by studying a three-legged antiferromagnetic quantum Ising ladder on a torus using tensor network methods, where topological frustration is induced by an odd number of spins along both spatial directions. Our results reveal the first instance in which topological frustration shifts the position of the quantum critical point. By studying the entanglement structure, we find that the ground state can be characterized as hosting three delocalized quasiparticles. This work builds the quasiparticle picture of topological frustration toward higher dimensions and more complex systems than those considered so far.
Strongly Correlated Electrons (cond-mat.str-el)
Ferromagnetism vs. Antiferromagnetism in Narrow-Band Systems: Competition Between Quantum Geometry and Band Dispersion
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Haoyu Hu, Oskar Vafek, Kristjan Haule, B. Andrei Bernevig
Magnetism in narrow-band systems arises from the interplay between electronic correlations, quantum geometry, and band dispersion. In particular, both ferro and anti-ferro magnets are known to occur as ground states of (different) models featuring narrow bands. This poses the question of which is favored and under what conditions. In this work, we present a unified theoretical framework to investigate spin physics within narrow bands. By deriving an effective spin model, we show that the non-atomic wavefunction of the narrow bands generally favors ferromagnetic ordering, while band dispersion promotes antiferromagnetic correlations. We find that the competition between these effects gives rise to a tunable magnetic phase and rich spin phenomena. Our approach offers a systematic way to study the magnetic properties of narrow-band systems, integrating the roles of wave function, band structure, and correlation effects.
Strongly Correlated Electrons (cond-mat.str-el)
36 pages, 2 figures
Magic continuum in multi-moiré twisted trilayer graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Li-Qiao Xia, Aviram Uri, Jiaojie Yan, Aaron Sharpe, Filippo Gaggioli, Nicole S. Ticea, Julian May-Mann, Kenji Watanabe, Takashi Taniguchi, Liang Fu, Trithep Devakul, Jurgen H. Smet, Pablo Jarillo-Herrero
Moiré lattices provide a highly tunable platform for exploring the interplay between electronic correlations and band topology. Introducing a second moiré pattern extends this paradigm: interference between the two moiré patterns produces a supermoiré modulation, opening a route to further tailor electronic properties. Twisted trilayer graphene generally exemplifies such a system: two distinct moiré patterns arise from the relative twists between adjacent graphene layers. Here, we report the observation of correlated phenomena across a wide range of twisted trilayer graphene devices whose twist angles lie along two continuous lines in the twist-angle parameter space. Depending on the degree of lattice relaxation, twisted trilayer graphene falls into two classes: moiré polycrystals, composed of periodic domains with locally commensurate moiré order, and moiré quasicrystals, characterized by smoothly varying local moiré configurations. In helically twisted moiré polycrystals, we observe an anomalous Hall effect, consistent with topological bands arising from domains with broken $ xy$ -inversion symmetry. In contrast, superconductivity appears generically in our moiré quasicrystals. A subset of these systems exhibits signatures of spatially modulated superconductivity, which we attribute to the supermoiré structure. Our findings uncover the organizing principles of the observed correlated phases in twisted trilayer graphene, highlight the critical roles of the supermoiré modulation and lattice relaxation, and suggest a broader framework in which magic conditions arise not as isolated points but as extended manifolds within the multi-dimensional twist-angle space of complex moiré materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
Dissociation of bulk and entanglement phase transitions in the Haldane phase
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
We revisit the momentum-resolved entanglement spectrum (ES) of the spin-1/2 ladder in the Haldane phase, long believed to exhibit a des Cloizeaux-Pearson (dCP)-type $ \sin|k|$ dispersion. Using exact diagonalization up to 40 spins, we resolve two distinct branches at $ k=0$ and $ k=\pi$ , which were previously interpreted as a single smooth mode due to SU(2) degeneracy and limited resolution. Breaking SU(2) symmetry via XXZ anisotropy opens a spin or neutral gap at $ k=\pi$ , depending on the anisotropy direction, triggering an entanglement quantum phase transition that is disconnected from the bulk critical point. In the easy-plane regime, the entanglement ground state is unique in the $ S_A^z=0$ sector but becomes quasi-degenerate across $ S_A^z$ sectors in the thermodynamic limit, consistent with spontaneous U(1) symmetry breaking. This separation between bulk and entanglement transitions demonstrates that the Li-Haldane correspondence can fail in topological ladders, even at the level of low-energy dispersions. These results revise the prevailing picture of ES in spin ladders under extensive bipartitioning, and suggest that the entanglement Hamiltonian, being nonlocal, can circumvent conventional constraints such as the Lieb-Schultz-Mattis and Mermin-Wagner theorems.
Strongly Correlated Electrons (cond-mat.str-el)
Weak-link to tunneling regime in a 3D atomic Josephson junction
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-09-05 20:00 EDT
Vijay Pal Singh, Erik Bernhart, Marvin Röhrle, Herwig Ott, Ludwig Mathey, Luigi Amico
We investigate the transition from weak-link transport to the tunneling Josephson regime in a three-dimensional (3D) Bose-Einstein condensate confined in a cylindrical, tube-like trap. By varying the height of a localized barrier, we map out the smooth crossover between these regimes through measurements of the critical current and Josephson oscillations. In the weak-link regime of the Josephson junction, dissipative transport is mediated by solitonic excitations in the form of vortex rings, which drive phase slips and generate a finite chemical potential difference across the junction. Increasing the barrier height suppresses these hydrodynamics excitations, yielding a tunneling-dominated Josephson regime characterized by phononic excitations. These findings elucidate the interplay between geometry, excitations, and dissipation in atomtronic weak links, and provide a quantitative framework for engineering coherent matter-wave circuits. Our results show excellent agreement with numerical simulations and analytical models.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
6+2 pages, 5+3 figures
Optical selection rules of topological excitons in flat bands
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Mara Lozano, Hong-Yi Xie, Bruno Uchoa
Topological excitons are superpositions of electron-hole pair states with an envelope wavefunction that has finite vorticity in momentum space, dictated by the topology of the electronic bands. We derive the optical selection rules for topological excitons in flat bands, considering different topological two-band models: a family of Hamiltonians with skyrmion pseudo-spin textures, the flattened BHZ model for a single spin, which can have a net Chern number, and the flattened Haldane model. We derive the selection rules for these three models accounting for short-range interactions. We also consider the non-hydrogenic spectrum of excitons in the single-spin flattened BHZ model with Coulomb interactions. We show that for the case of two flat bands with skyrmion pseudo-spin textures, all excitons are bright, and the handedness of the light that couples to them is fixed by the vorticity of the pseudo-spin texture. For the single-spin flattened BHZ model, we show that bright excitons couple to circularly polarized light, regardless the range of the interactions. In the flattened Haldane model, we find that topological excitons couple to elliptically polarized light. We obtain the phase diagram for the polarization of light in this model as a function of the microscopic parameters of the Hamiltonian.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 5 figures
Mott Glass and Criticality in a S=1/2 Bilayer Heisenberg Model with Interlayer Bond Dilution
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Kunpeng Li, Han-Qing Wu, Dao-Xin Yao
We employ the stochastic series expansion quantum Monte Carlo (SSE-QMC) method to investigate the $ S = 1/2$ antiferromagnetic Heisenberg model on a bilayer square lattice with diluted interlayer couplings. Both regular and random dilution patterns are considered. In systems with regular dilution, tuning the interlayer interaction drives a quantum phase transition from a Néel-ordered phase to a quantum disordered phase, consistent with the $ O(3)$ universality class. In contrast, random dilution gives rise to a two-step transition: from the Néel phase to an intermediate Mott glass (MG) phase, followed by a transition to the quantum disordered phase. Within the MG phase, the uniform magnetic susceptibility exhibits a stretched-exponential temperature dependence $ \chi_u \sim \exp(-b/T^\alpha)$ , $ 0 < \alpha < 1$ . At the Néel-to-glass transition, quenched disorder modifies the critical exponents in a manner consistent with the Harris criterion. These findings provide new insights into disorder-driven quantum phase transitions and the emergence of glassy phases in diluted bilayer quantum magnets.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech)
Coherent control of thermoelectric performance via engineered transmission functions in multi-dot Aharonov-Bohm heat engine
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Sridhar, Salil Bedkihal, Malay Bandyopadhyay
We theoretically investigate strategies for harnessing quantum interference to optimize the figure of merit $ ZT$ , power output, and thermodynamic efficiency in multi-quantum-dot Aharonov-Bohm (AB) thermoelectric heat engines. Using the non-equilibrium Green function formalism, we show that interference effects such as Fano-type asymmetries, Dicke-like superradiant and subradiant modes, and multi-peaked transmission spectra can be tailored through device geometry, magnetic flux, and dot-lead coupling to produce hybrid transmission profiles that combine Lorentzian, boxcar, and Fano lineshapes. Such engineered profiles enable configurations that balance the high efficiency of sharp Lorentzian resonances with the high power output of boxcar-like spectra, yielding near-optimal power-efficiency trade-offs. For symmetric quantum-dot arrays in square, pentagonal, and hexagonal configurations, we identify an optimal regime, $ t/\gamma \approx 2$ , where the interdot tunneling amplitude $ t$ and the dot-lead coupling $ \gamma$ yield the best balance of power and efficiency. A hexagonal six-dot configuration achieves $ ZT \sim 30$ at dilution temperatures, while the four-dot geometry reaches about $ 76%$ of Carnot efficiency with output power $ 4.74$ fW. We also find a direct correspondence between the high-$ ZT$ regime and maximal violation of the Wiedemann-Franz law. Introducing source-drain coupling asymmetry further enhances both efficiency and power. A scaling analysis reveals that efficiency systematically increases with the number of quantum dots, whereas power output is maximized at intermediate system sizes. These findings establish coherent control in multi-dot nanostructures as a promising pathway toward high-performance quantum thermoelectric heat engines for ultralow-power electronics applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
19 pages, 8 figures
Three-channel charge Kondo model at high transparency
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Nicolas Paris, Nicolas Dupuis, Christophe Mora
Quantum impurity models involving a localized charge that is weakly coupled to electronic leads usually map to Kondo-like Hamiltonians that exhibit various quantum critical behaviors. Here, we address the opposite regime of high contact transparency by solving the model of a quantum island coupled to three quantum Hall edge channels. Using a functional renormalization group (FRG) approach, we demonstrate that the low-energy physics is controlled by a nonperturbative fixed point. The universal energy crossover in both the linear conductance and the impurity entropy is obtained. We reproduce the zero-frequency conductance and the leading low-energy exponent of the three-channel Kondo model, confirming their universality across all transparencies. For interacting leads – a model that continuously connects to the pseudo-gap Kondo model at low transparency – we find a line of fixed points as the Luttinger parameter $ K$ , which encodes the strength of the interactions, changes. Our work demonstrates that FRG methods are an efficient tool for solving quantum impurity problems in regimes where standard approaches fail.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
7+15 pages, 4+6 figures
Topological edge states in a double isomeric Class-II oligo(indenoindene)
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
I report the theoretical prediction of non-trivial physics in a one dimensional multiradical system consisting in fused six and five membered $ {\pi}$ -conjugated carbon rings, known as oligo(indenoindene) (OInIn). Topologically protected electronic states may emerge in fermionic chains if there is an alternation in the coupling of adjacent unpaired electrons, being described effectively by the Su-Schrieffer-Heeger (SSH) model. Class-II OInIn isomers act as tight-binding chains in the non-interacting regime, thus we can expect the emergence of SSH physics in an OInIn produced by the combination of two isomers that belong to this class. That is the case of the system studied in this manuscript, whose calculated non-interacting band structure shows a gap opening compared to the gapless pure isomeric forms, hosting ingap localized states at the chain termini depending on the termination, and a non-zero Zak phase that confirms the non-trivial topology. These results were consistent with spin unrestricted mean-field Hubbard and density functional theory calculations, showing antiferromagnetic unquenched local magnetic moments at the pentagons, and strong edge localization depending on the termination. This work advances in the understanding of the physics of non-alternant multiradical $ {\pi}$ -conjugated hydrocarbons.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Emergent Rashba spin-orbit coupling in bulk gold with buried network of nanoscale interfaces
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Shreya Kumbhakar, Banashree Debnath, Tuhin Kumar Maji, Binita Tongbram, Shinjan Mandal, T. Phanindra Sai, T.V. Ramakrishnan, Manish Jain, H. R. Krishnamurthy, Anshu Pandey, Arindam Ghosh
The Rashba effect, which plays a crucial role in fundamental materials physics and potential spintronics applications, has been engineered in diverse systems, including semiconductor quantum wells, oxide heterostructures, metallic surfaces, topological insulators, ferroelectrics, etc. However, generating it in systems that preserve bulk inversion symmetry (BIS), for example, in bulk metals, has not been possible so far. We demonstrate a unique strategy to introduce and tune Rashba spin-orbit interaction (SOI) to unprecedented magnitudes in inversion-symmetric solids, by incorporating ultra-small silver nanoparticles in bulk gold. The near-identical lattice constants of Ag and Au allowed dense packing of the Ag/Au hetero-interfaces without compromising the global BIS. By varying the density of embedded nanoparticles, we generate Rashba SOI in a bulk metal with a coupling strength of ~15 this http URL, higher than any known system preserving BIS globally, and up to ~20 times increase in the spin-orbit scattering rate. We argue that the combined effect of charge-transfer at the interfaces and polaronic localization enhances the SOI.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages,5 figures
A One-Particle Density Matrix Framework for Mode-Shell Correspondence: Characterizing Topology in Higher-Order Topological Insulators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Miguel F. Martínez, Lucien Jezequel, Jens H. Bardarson, Thomas Klein Kvorning, Julia D. Hannukainen
We present a framework for characterizing higher-order topological phases directly from the one-particle density matrix, without any reference to an underlying Hamiltonian. Our approach extends the mode-shell correspondence, originally formulated for single-particle Hamiltonians, to Gaussian states subject to chiral constraints. In this correspondence, the mode index counts topological boundary modes, while the shell index quantifies the bulk topology in a surrounding region, providing a bulk-boundary diagnostic. In one-dimensional topological insulators, the shell index reduces to the local chiral marker, recovering the winding number in the translation-invariant limit. We apply the mode-shell correspondence to a $ C_4$ -symmetric higher-order topological insulator with a chiral constraint and show that a fractional shell index implies that the higher-order phase is intrinsic. The one-particle density matrix is formulated in real space, so the mode-shell correspondence applies to models without translation invariance. By introducing structural disorder into the $ C_4$ -symmetric higher-order insulator, we show that the mode-shell correspondence remains a meaningful diagnostic in the amorphous limit. The mode-shell correspondence generalizes to interacting states with a gapped bulk spectrum in the one-particle density matrix, providing a practical and diverse route to characterize higher-order topology from the quantum state itself.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Disordered Systems and Neural Networks (cond-mat.dis-nn)
9 pages, 2 figures
Applying a Gaussian networking theory to model motor-driven transport along cytoskeletal filaments
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Nadine du Toit (1), Kristian K. Müller-Nedebock (1,2) ((1) Department of Physics, Stellenbosch University, Stellenbosch, South Africa, (2) National Institute for Theoretical and Computational Sciences, Stellenbosch, South Africa)
This paper builds on a recently introduced dynamical networking framework, applying it to model motor-driven transport along cytoskeletal filament networks. Within this approach, the networking functional describes the periodic binding and unbinding of motors to available filament sites,whilst accounting for all possible pairing, enabling a field-theoretic treatment of constrained motion in complex networks. In this application, the dynamical networking theory is introduced into a Martin-Siggia-Rose representation of the Langevin dynamics describing the motion of a motor protein and its cargo. Results are presented in a collective description of motors on a network, for two different scenarios, namely homogeneous and non-homogeneous networks. A diffusion coefficient is presented for homogeneous networks, whilst it is shown that various possibilities remain for disordered averaging over network densities for non-homogeneous networks.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
10 pages, 3 figures
Geometric Effects on Tunneling in Driven Quantum Systems
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Shintaro Takayoshi, Takashi Oka
We review quantum tunneling provoked by external field driving, focusing on the role of geometric effects. The discussion begins with an overview of tunneling phenomena, including the Landau-Zener model and the Schwinger effect, both of which are essential frameworks to describe the generation of elementary excitation of the system. We also refer to the relation between the modern theory of polarization and the geometry of the system, and introduce the shift vector via adiabatic perturbation theory. Then we introduce the twisted Landau-Zener model and shown how the shift vector modulates tunneling probability, followed by several illustrative applications of this model. We also explain the Keldysh crossover, which is the crossover from a quantum tunneling regime to photon absorption regime in driven systems.
Strongly Correlated Electrons (cond-mat.str-el)
9 pages, 4 figures
Attention is all you need to solve chiral superconductivity
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-05 20:00 EDT
Chun-Tse Li, Tzen Ong, Max Geier, Hsin Lin, Liang Fu
Recent advances on neural quantum states have shown that correlations between quantum particles can be efficiently captured by {\it attention} – a foundation of modern neural architectures that enables neural networks to learn the relation between objects. In this work, we show that a general-purpose self-attention Fermi neural network is able to find chiral $ p_x \pm i p_y$ superconductivity in an attractive Fermi gas by energy minimization, {\it without prior knowledge or bias towards pairing}. The superconducting state is identified from the optimized wavefunction by measuring various physical observables: the pair binding energy, the total angular momentum of the ground state, and off-diagonal long-range order in the two-body reduced density matrix. Our work paves the way for AI-driven discovery of unconventional and topological superconductivity in strongly correlated quantum materials.
Superconductivity (cond-mat.supr-con)
15 pages, 9 figures, 1 table
Double quantum dots with quenched charging energy in PbTe nanowires
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Seth Byard, Maksim Gomanko, Adam Raynolds, Susheng Tan, Tongxie Zhang, Shixiong Zhang, Sergey M. Frolov
We investigate double quantum dots defined by electrostatic gating in semiconductor PbTe nanowire devices. We perform transport measurements to obtain charge stability diagrams distinguished by negligible separation between paired triple points and by the spin degeneracy of all transport resonances at zero magnetic field. We show a fourfold splitting of high-bias stability diagram triangles in an applied magnetic field to illustrate the lifting of this spin degeneracy. We also identify patterns of narrow transport resonances in these high-bias triangles and discuss their possible physical origins. Our results represent a step towards the realization of PbTe-based spin qubits.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Full data available at DOI:https://doi.org/10.5281/zenodo.17031945
Twisted quantum doubles are sign problem-free
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
The sign problem is one of the central obstacles to efficiently simulating quantum many-body systems. It is commonly believed that some phases of matter, such as the double semion model, have an intrinsic sign problem and can never be realized in a local sign problem-free Hamiltonian due to the non-positivity of the wavefunction. We show that this is not the case. Despite failing to be stoquastic - the standard criteria for the existence of a sign problem - the double semion model as well as all twisted quantum double phases of matter for finite groups $ \mathcal{G}$ can be realized in local sign problem-free Hamiltonians. The lack of a sign problem is not fine-tuned and does not require the Hamiltonian to be exactly solvable, with sign problem-free perturbations allowing access to a variety of topological phase transitions.
Strongly Correlated Electrons (cond-mat.str-el)
10 pages, feedback or references are welcome
Surface Passivation for Halide Optoelectronics: Comparing Optimization and Reactivity of Amino-Silanes with Formamidinium
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Zixu Huang, Farhad Akrami, Junxiang Zhang, Stephen Barlow, Seth R. Marder, David S. Ginger
Amino-silane-based surface passivation schemes are gaining attention in halide perovskite optoelectronics, with varying levels of success. We compare surface treatments using (3-aminopropyl)trimethoxysilane (APTMS) and [3-(2-aminoethylamino)propyl]trimethoxysilane (AEAPTMS), applied via room-temperature vacuum deposition, to the perovskite FA0.78Cs0.22Pb(I0.85Br0.15)3 (FA = formamidinium). Both molecules improve thin-film photoluminescence properties and photovoltaic device performance, although their effectiveness depends strongly on deposition time. We show AEAPTMS has a wider, more robust processing window and yields higher performance under optimized conditions. In contrast, over-exposure, particularly with APTMS, reduces performance, with notable reductions in photoluminescence lifetime and absorbance. To probe the underlying chemistry, we employ nuclear magnetic resonance (NMR) spectroscopy and depth-resolved time-of-flight secondary ion mass spectrometry (ToF-SIMS), demonstrating that both amino-silanes react with formamidinium (FA+) cations in solution and in the solid state. This work underscores the importance of optimizing deposition conditions to balance effective passivation with potential performance loss and elucidates previously unrecognized reactive chemistry between amino-silane passivating agents and halide perovskites.
Materials Science (cond-mat.mtrl-sci)
Link Statistics of Dislocation Network during Strain Hardening
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Sh. Akhondzadeh, Hanfeng Zhai, Wurong Jian, Ryan B. Sills, Nicolas Bertin, Wei Cai
Dislocations are line defects in crystals that multiply and self-organize into a complex network during strain hardening. The length of dislocation links, connecting neighboring nodes within this network, contains crucial information about the evolving dislocation microstructure. By analyzing data from Discrete Dislocation Dynamics (DDD) simulations in face-centered cubic (fcc) Cu, we characterize the statistical distribution of link lengths of dislocation networks during strain hardening on individual slip systems. Our analysis reveals that link lengths on active slip systems follow a double-exponential distribution, while those on inactive slip systems conform to a single-exponential distribution. The distinctive long tail observed in the double-exponential distribution is attributed to the stress-induced bowing out of long links on active slip systems, a feature that disappears upon removal of the applied stress. We further demonstrate that both observed link length distributions can be explained by extending a one-dimensional Poisson process to include different growth functions. Specifically, the double-exponential distribution emerges when the growth rate for links exceeding a critical length becomes super-linear, which aligns with the physical phenomenon of long links bowing out under stress. This work advances our understanding of dislocation microstructure evolution during strain hardening and elucidates the underlying physical mechanisms governing its formation.
Materials Science (cond-mat.mtrl-sci), Data Analysis, Statistics and Probability (physics.data-an)
17 pages, 11 figures
Lattice dynamics of the infinite-layer nickelate LaNiO$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Shohei Hayashida, Vignesh Sundaramurthy, Wenfeng Wu, Pascal Puphal, Thomas Keller, Björn Fåk, Masahiko Isobe, Bernhard Keimer, Karsten Held, Liang Si, Matthias Hepting
Infinite-layer (IL) nickelates have rapidly emerged as a new class of superconductors. However, due to the technical challenges of their topotactic synthesis, they have so far been realized primarily as thin films or polycrystalline powder samples, limiting comprehensive investigations of fundamental physical properties such as the lattice dynamics. Here, we present a time-of-flight inelastic neutron scattering study on a sample composed of a large number of co-aligned bulk crystals of the IL nickelate LaNiO$ _2$ . We observe several dispersive phonon branches, which are in good agreement with lattice dynamical calculations based on density-functional perturbation theory. In addition, we compare the characteristics of selected LaNiO$ _2$ phonon modes to those of isostructural cuprate superconductors. Our findings provide a reference point for future experimental and theoretical efforts aimed at understanding the interplay between lattice dynamics and electronic properties in IL nickelates.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
Proximitizing altermagnets with conventional superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-05 20:00 EDT
Niclas Heinsdorf, Marcel Franz
Recent theoretical work highlighted unique properties of superconducting altermagnets, including the wealth of topologically non-trivial phases as well as their potential uses in spintronic applications. Given that no intrinsically superconducting altermagnets have yet been discovered, we study here the possibility of superconducting order induced by proximity effect from a conventional s-wave superconductor. Through symmetry analysis and microscopic modeling we find that interesting superconducting phases can indeed be proximity-induced in a thin altermagnetic film provided that weak Rashba spin-orbit coupling is present at the interface. Surprisingly, the resulting superconductor is generically nodal with a mixed singlet/triplet order parameter and, importantly for applications, capable of generating spin-polarized persistent current. We propose a set of candidate heterostructures with low lattice mismatch suitable to probe these effects experimentally.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Plasmons in a network of topological states in twisted bilayer graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Brian S. Vermilyea, Michael M. Fogler
We study surface plasmons in minimally-twisted bilayer graphene that contains a triangular network of partial dislocations (or AB-BA domain walls) hosting one-dimensional electronic states. We calculate plasmon dispersion by solving classical equations of motion for charge dynamics on the network links with impedance boundary conditions at the network nodes. The plasmon band structure is shown to be quasi-periodic in frequency and damped everywhere except at high-symmetry points of the moiré Brillouin zone. We compare our network-based formalism with the conventional random phase approximation and discuss when each approach is valid. Calculations of plasmon waves launched by local scatterers are presented to simulate terahertz nano-imaging experiments.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Controllable Josephson diode effect, $0$-$π$ transition and switch effect in the superconductor/two-dimensional Weyl nodal line semimetal/superconductor junctions
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-05 20:00 EDT
Wen-Ting Liu, Shu-Chang Zhao, Qiang Cheng, Qing-Feng Sun
We study the Josephson effects in the superconductor/two-dimensional Weyl nodal line semimetal/superconductor junctions using the Green’s function method. When the Rashba spin-orbit coupling and an external magnetic field coexist in the semimetal, the symmetries protecting the reciprocity of supercurrent can be broken and the Josephson diode effect with the nonreciprocity of supercurrent can be realized. A high efficiency exceeding $ 40%$ can be achieved with the experimentally accessible values of the magnetic field and the Rashba spin-orbit coupling. The diode efficiency can be easily controlled by the direction and magnitude of the field and the strength of the spin-orbit coupling. When the spin-orbit coupling is absent or the external field is absent, the Josephson diode effect vanishes but the current-phase difference relations still show strong dependence on the field or the coupling. The tunable $ 0$ -$ \pi$ transition and the switch effect of supercurrent in the junctions can be formed if the direction of the field is rotated or the magnitude of the field and the strength of the coupling are changed. The obtained Josephson diode effect, the $ 0$ -$ \pi$ transition and the switch effect of supercurrent are helpful in the design of the quantum devices based on nodal line semimetals.
Superconductivity (cond-mat.supr-con)
10pages,7figures
Physical Review B 112 (2025) 054509
Spin Splitting Nernst Effect in Altermagnet
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Xing-Jian Yi, Yue Mao, Xiancong Lu, Qing-Feng Sun
Altermagnet is a distinctive magnet phase, which has spin-split energy band but with zero net magnetic moment. In this paper, we propose that altermagnet behaves spin splitting Nernst effect: Under a longitudinal temperature gradient, the electrons with opposite spins tend to split oppositely in the transverse direction, thus generating a transverse spin current. The spin splitting Nernst effect is understood from the contribution of the longitudinal wave vector to the transverse group velocity. Using the nonequilibrium Green’s function method, we calculate the spin-dependent transmission coefficient in the four-terminal altermagnet device. From the spin-dependent transmission coefficient, the nonzero transverse spin current from longitudinal temperature gradient is obtained, and the spin splitting Nernst effect is verified. We systematically study the parameter dependence of the spin splitting Nernst effect, while also performing symmetry analysis. The spin splitting Nernst effect can be easily regulated by Fermi surface energy, temperature, transport direction, and system size. Furthermore, in altermagnet, the $ xy$ -response and $ yx$ -response spin splitting Nernst coefficients are equal with $ N_{s,xy}=N_{s,yx}$ , different from the conventional spin Nernst effect where they are opposite. Meanwhile, the spin splitting Nernst effect require neither spin-orbit coupling nor net magnetism.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Merons and Meroniums in Spin-Orbit Coupled Bose Gases
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-09-05 20:00 EDT
Bo Chen, Xiaojing Jin, Jiatao Tan, Boyang Liu
In this work we demonstrate the existence of new types of topological states in a two-component Bose gas with Rashba spin-orbit couplings. We find four types of topological structures exist in this system. First, the half vortex (HV), which have been found and discussed in similar systems. Second, the spherical wave half vortex (SWHV), which is different from the HV by a factor of $ e^{ikr}$ in the wave function. The spin configurations show that HV and SWHV are both merons. Of particular interests are the third and fourth types, which are called double peak (DP) and spin spiral (SS) phases. They are both combinations of meron and antimeron, and hence named as meroniums. These two phases demonstrate intriguing spin density patterns. Finally, the phase diagram is obtained and the stability of the meronium state is discussed.
Quantum Gases (cond-mat.quant-gas)
5 pages, 4 figures
Switching topological states via uniaxial strain in 2D materials
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Joshua J. Sanchez, Raagya Aurora, Daniel Bennett, Daniel T. Larson, Efthimios Kaxiras, Riccardo Comin
In topological materials, dissipationless edge currents are protected against local defect scattering by the bulk inverted band structure and band gap. We propose that large uniaxial strain can effectively switch a 2D Chern insulator to a topologically trivial state. Further, we suggest that the boundary between strained and unstrained regions of a sample can act as a new edge for dissipationless current flow. Using density functional theory (DFT) calculations we demonstrate the strain-tunability of the monolayer MnBi2S2T2 band structure and the switching of the Chern number. We combine uniaxial and biaxial strain results to map out the strain-tuned topological phase diagram.
Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 4 figures
Unconventional superconductivity in monolayer transition metal dichalcogenides
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-05 20:00 EDT
Subhojit Roy, Andreas Kreisel, Brian M. Andersen, Shantanu Mukherjee
A variety of experimental observations in monolayer transition metal dichalcogenide superconductors with Ising spin-orbit coupling suggest the presence of an unconventional superconducting pairing mechanism. Some of these experiments include observation of Leggett modes and a nodal superconducting gap in STM experiments, a large in-plane upper critical field compared to the Pauli limit, and the observation of a two-fold gap anisotropy in magnetoresistance measurements. Here, we propose a superconducting pairing mechanism mediated by spin and charge fluctuations and identify the dominant superconducting instability relevant to monolayer TaS$ _2$ . We then explore the effect of an additional electron-phonon pairing contribution, and compare our results with recent experimental findings. In particular, our theory stabilizes a superconducting ground state with nodal-like density of states that agrees with STM experiments. The theory obtains a large in-plane upper critical field due to a combination of Ising spin-orbit coupling and even-odd parity mixing in the superconducting state. Further, we find that an in-plane magnetic field splits the degeneracy of the superconducting ground state, and the resulting two-fold symmetric superconducting order parameter could explain the gap anisotropy observed in magnetoresistance experiments. Overall, the proposed theoretical pairing model can reconcile diverse experimental observations and remains consistent with observations on other dichalcogenide superconductors such as monolayer NbSe$ _2$ .
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
15 pages, 14 figures
Strongly correlated electrons in superconducting islands with fluctuating Cooper pairs
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Tie-Feng Fang, Ai-Min Guo, Qing-Feng Sun
We present a particle-number conserving theory for many-body effects in mesoscopic superconducting islands connected to normal electrodes, which explicitly includes quantum fluctuations of Cooper pairs in the condensate. Beyond previous BCS mean-field descriptions, our theory can precisely treat the pairing and Coulomb interactions over an unprecedentedly broad range of parameters by using the numerical renormalization group method. On increasing the ratio of pairing to Coulomb interactions, the low-energy physics of the system evolves from the spin Kondo to mixed valence regimes and eventually reaches an anisotropic charge Kondo phase, while a crossover from $ 1e$ - to $ 2e$ -periodic Coulomb blockade of transport is revealed at high temperatures. For weak pairing, the superconducting condensate is frozen in the local spin-flip processes but fluctuates in the virtual excitations, yielding an enhanced spin Kondo temperature. For strong pairing, massive fluctuations of Cooper pairs are crucial for establishing charge Kondo correlations whose Kondo temperature rapidly decreases with the pairing interaction. Surprisingly, a charge-exchange induced local field may occur even at the charge degenerate point, thereby destroying the charge Kondo effect. These are demonstrated in the spectral and transport properties of the island.
Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 3 figures
Phys. Rev. B 106, 075117 (2022)
Superconducting lens and Josephson effect in AA-stacked bilayer graphene
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-05 20:00 EDT
Wei-Tao Lu, Tie-Feng Fang, Qing-Feng Sun
We study the superconducting transport phenomena, involving lensing effect and supercurrent in AA-stacked bilayer graphene, which is characterized by a linear gapless band with two shifted Dirac cones. Our findings indicate that cross Andreev reflection and Josephson current occur exclusively within the intracone process, while intercone scatterings are strictly prohibited. The normal/superconductor/normal junction can act as a superconducting lens for the upper and lower cones. Depending on cone index, the transmitted electrons and holes can be focused, collimated or diverged by adjusting the gate voltages. In superconductor/normal/superconductor junction, due to interlayer coupling, the critical currents of the two cones exhibit distinct oscillation periods with junction width, leading to an irregular oscillation of the total critical current. Furthermore, the oscillations of critical currents with exchange field maintain a stable phase difference of one quarter period between the two cones. Consequently, a cone-dependent 0-\pi transition is achieved in this Josephson junction.
Superconductivity (cond-mat.supr-con)
Physical Review B 111, 165411 (2025)
Atomic collapse of high-order singular potentials in graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Yu-Chen Zhuang, Yue Mao, Qing-Feng Sun
Artificial atoms in graphene hosting a series of quasi-bound states can serve as an excellent platform to explore atomic collapse and become a basis to design novel graphene nanodevices. We theoretically study behaviors of massless Dirac fermions in singular potentials with a general form of 1/r^{\gamma}. Different from the Coulomb potential that demands a supercritical charge Z > Zc, a high-order singular potential ({\gamma} > 1) is found to in principle induce atomic collapse with an infinitesimal charge Z. The energies of atomic collapse states (ACSs) within these potentials are arranged roughly as a power sequence. We also show that some special ACSs can exist even above the bulk Dirac point, which cannot appear in the Coulomb potential. These findings uncover the anomalies of massless Dirac fermions in diverse charge potentials and provide guidance for further experiments and graphene nanodevice applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
16 pages, 11 figures
Physical Review B Vol. 111, Iss. 24, L241407 June 2025
Antiferromagnetic superlattices: anisotropic band and spin-valley valve in buckled two-dimensional materials
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Wei-Tao Lu, Tie-Feng Fang, Qing-Feng Sun
Antiferromagnetic superlattices (AFSL) are proposed based on the buckled hexagonal two-dimensional materials, which can be realized by the proximity effect of the periodically deposited antiferromagnets. It is found that the AF proximity effect can give rise to valley-polarized minibands and conductance, which are not held under ferromagnetic proximity. The spin degeneracy and valley degeneracy are lifted simultaneously in the presence of AF proximity and electric field. In consequence, both minibands and conductance could be spin-valley polarized completely in AFSL. The symmetry of spin-valley polarization is analysed by considering the pseudospin rotation operations and spatial inversion operations. Furthermore, AFSL also induce a highly anisotropic band structure due to the spin-orbit coupling (SOC). In particular, the group velocity parallel to the periodic direction of AFSL is greatly renormalized, while the velocity perpendicular to the periodic direction remains unaffected, contrary to that observed in graphene superlattices. With the increase of SOC, the anisotropy becomes more prominent, leading to flattened band and electron supercollimation. The direction of anisotropy can be regulated by adjusting the potential and SOC. These findings offer an alternative approach to engineering anisotropic two-dimensional materials. As an application, the AFSL may well work as a symmetry-protected spin-valley valve easily controlled by the gate voltages.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Physical Review B 110, 035426 (2024)
Frustration-enhanced persistent currents in correlated trimer nanorings
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Tie-Feng Fang, Wei-Tao Lu, Ai-Min Guo, Qing-Feng Sun
We investigate the persistent current in a correlated trimer nanoring comprising of three magnetic atoms, which sits on a metallic host and encloses a magnetic flux. In the molecular-orbital regime, charge fluctuations can reverse the aromaticity of the trimer molecule by driving quantum phase transitions between many-body states. It is shown that in frustrated trimers the superexchange-induced current as a function of interatom hopping is enhanced by the competition of conflicting magnetic orders, with an asymmetric peak at the quantum criticality separating the ferromagnetic and antiferromagnetic Kondo regimes. Interestingly, the critical current undergoes an anomalous rise with temperature before decaying, signaling the suppression of Kondo bound state at finite temperature. Our results demonstrate that the coherent current response to external flux indeed conveys important information on the states of strongly correlated systems.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 4 figures
Phys. Rev. B 111, L081117 (2025)
Topologically protected magnetoresistance by quantum anomalous Hall effect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Recently, antiferromagnetic (AF) materials have attracted rapid attention, because they are considered as outstanding candidates to replace the widely used ferromagnets in the next generation of spintronics. We propose a magnetoresistance model based on the quantum anomalous Hall effect in an AF system, which is protected by the topological Chern number. By regulating the AF exchange field and an electric field, the system can be controlled between the quantum spin Hall insulator (QSHI) phases and the quantum anomalous Hall insulator (QAHI) phases. As a result, a QAHI/QSHI/QAHI junction can be formed. In the QAHI region, the spin orientation of chiral edge state can be manipulated by tuning the AF exchange field and the electric field. Therefore, the spin directions of two QAHIs in the junction can have parallel and antiparallel configurations. The conductances of two configurations offered by chiral edge states are significantly different, and this is a magnetoresistance effect that can be electrically controlled. Because of the topological invariance, the magnetoresistance plateaus are robust to the size effect and the disorder.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Physical Review B 108, 075422 (2023)
Two-dimensional coherent spectroscopy of disordered superconductors in the narrow-band and broad-band limits
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-05 20:00 EDT
We theoretically analyze two-dimensional coherent spectroscopy (2DCS) signals for disordered superconductors in two limits: One is the narrow-band limit with sinusoidal pulse waves, and the other is the broad-band limit with delta-function pulses. While the 2DCS signal in the narrow-band limit is related to the third-order nonlinear susceptibilities $ \chi^{(3)}(3\Omega; \Omega, \Omega, \Omega)$ (third harmonic generation) and $ \chi^{(3)}(\Omega; \Omega, \Omega, -\Omega)$ (ac Kerr effect), we find that in the broad-band limit the signal along the diagonal and horizontal lines in the two-dimensional frequency space is related to another nonlinear susceptibility $ \chi^{(3)}(\Omega; \Omega, 0, 0)$ (dc Kerr effect). We numerically evaluate those susceptibilities for a lattice model of superconductors based on the BCS mean-field theory and self-consistent Born approximation for impurities. The 2DCS signals in the narrow-band and broad-band limits show threshold and resonance behaviors at the superconducting-gap frequency, respectively, whose physical origin is discussed in light of quasiparticle and Higgs-mode excitations.
Superconductivity (cond-mat.supr-con)
22 pages, 14 figures
Thickness-dependent magnon spin transport in antiferromagnetic insulators: Crossover from quasi-three-dimensional to quasi-two-dimensional regimes
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Mathias Åsan Myhre, Verena Brehm, Thomas Delvaux, Arne Brataas, Alireza Qaiumzadeh
Motivated by the recent observation of giant room-temperature magnon spin conductivity in an ultrathin ferromagnetic insulator [X.-Y. Wei et al., Nat. Mater. 21, 1352 (2022)], we investigate thickness-dependent magnon spin transport in thin antiferromagnetic insulators (AFIs). We study the prototypical AFI hematite, known for its exceptionally low magnetic damping and two distinct magnetic phases: a low-temperature uniaxial easy-axis phase and a high-temperature biaxial easy-plane phase. Using stochastic micromagnetic simulations, we investigate thickness-dependent magnon spin transport across both magnetic phases. Our results uncover a crossover from quasi-three-dimensional to quasi-two-dimensional magnon spin transport at a critical thickness, determined by the frequency or energy of the excited magnons. Below this critical thickness, we observe a pronounced enhancement in the magnon diffusion length in both magnetic phases. This rise is attributed to a change in the effective magnon density of states, reflecting the reduced phase space available for scattering in the thinner, quasi-two-dimensional regime. Understanding and controlling long-distance magnon spin transport in AFIs is crucial for developing next-generation spintronic nanodevices, especially as materials approach the two-dimensional limit.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Two-dimensional Dirac semimetals with tunable edge states
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Lizhou Liu, Cheng-Ming Miao, Qing-Feng Sun, Ying-Tao Zhang
We theoretically propose a design for two-dimensional Dirac semimetals using a bilayer-modified Bernevig-Hughes-Zhang (BHZ) model. By introducing new sites into the BHZ model, we engineer flat bands at the Fermi energy. In the bilayer system, interlayer coupling separates these flat bands, resulting in two Dirac points that preserve time-reversal and inversion symmetries. Two Dirac points are connected by a one-dimensional Fermi arc edge state, whose bound nature is confirmed by quantized transmission resonance peaks. Notably, the position of the Dirac points can be precisely tuned by adjusting interlayer coupling strengths and symmetries.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Two-Dimensional Higher-Order Topological Metals
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Lizhou Liu, Cheng-Ming Miao, Qing-Feng Sun, Ying-Tao Zhang
We investigate the energy band structure and energy levels of graphene with staggered intrinsic spin-orbit coupling and in-plane Zeeman fields. Our study demonstrates that staggered intrinsic spin-orbit coupling induces bulk band crossover at the the ( K ) and ( K’ ) valleys and generates antihelical edge states at the zigzag boundaries, resulting in topological metallic phases. Quantized transport coefficients confirm the existence of these antihelical edge states. Furthermore, an in-plane Zeeman field, regardless of orientation, opens a gap in the antihelical edge states while preserving bulk band closure, leading to higher-order topological metals with corner states. We also validate the presence of these corner states in nanoflakes with zigzag boundaries and confirm the metallic phases with crossed bands through a continuum low-energy model analysis.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Tunable Majorana corner states driven by superconducting phase bias in a vertical Josephson junction
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-05 20:00 EDT
Cheng-Ming Miao, Yu-Hao Wan, Ying-Tao Zhang, Qing-Feng Sun
The realization and manipulation of Majorana zero modes is a key step in achieving topological quantum computation. In this paper, we demonstrate the existence of Majorana corner states in a superconductor-insulators-superconductor vertical Josephson junction. The position of these Majorana corner states can be precisely and easily controlled by the superconducting phase bias, which be confirmed through both numerical and edge state theoretical analysis. In addition, we propose a protocol for achieving topological braiding of the Majorana corner states in a system of three circular vertical Josephson junctions. Our findings advance the field of topological quantum computation by providing new insights into the efficient and precise manipulation of Majorana corner states.
Superconductivity (cond-mat.supr-con)
11 pages, 7 figures
Altermagnetism-Induced Parity Anomaly in Weak Topological Insulators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
We demonstrate that introducing altermagnetism on the surface of a weak topological insulator (TI) results in the emergence of a single massless Dirac fermion, exhibiting a parity anomaly. To explore the transport properties induced by this parity anomaly, we propose an effective two-dimensional (2D) lattice model to describe the weak TI surface. This model captures both the energy spectrum and spin texture of the weak TI surface while reducing computational complexity. We show that the weak TI surface hosts a half-integer chiral edge current under the influence of altermagnetism. Additionally, in the presence of decoherence, the Hall conductance attains a half-quantized value. Layer-resolved calculations from a 3D slab model further confirm that surface altermagnetism drives the surface Hall conductance to transition to $ e^{2}/2h$ , aligning with calculation from the 2D effective lattice model. Our findings establish a link between altermagnetism and quantum anomalies, positioning weak TIs as a potential platform for investigating the parity anomaly without a net magnetic moment.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Interplay of Altermagnetic Order and Wilson Mass in the Dirac Equation: Helical Edge States without Time-Reversal Symmetry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Yu-Hao Wan, Peng-Yi Liu, Qing-Feng Sun
We investigate topological phases in three-dimensional topological insulator (3DTI) thin films interfaced with altermagnetic (AM) orders. Starting from a modified Dirac equation, we elucidate the interplay between the Wilson mass, arising from lattice regularization, and the altermagnetic mass, and show how this interplay fundamentally alters the band topology and boundary modes. In particular, we demonstrate that coupling a 3DTI thin film to AM order induces a topological phase transition: although the total Chern number remains zero across the transition, topological helical edge states emerge after the transition. These helical edge states arise from opposite Chern numbers at different high-symmetry points, and are distinct from both the chiral edge states of the quantum anomalous Hall phase and the helical edge states of the conventional quantum spin Hall states. The quantum transport simulations reveal robust, quantized nonlocal resistance plateaus associated with these helical edge states, which persist even under strong potential and magnetic disorder. Our results establish 3DTI/AM heterostructures as a feasible material platform for engineering and detecting helical topological edge transport without time-reversal symmetry, thus expanding the landscape of topological matter and providing new opportunities for quantum devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Orientational phase transitions induced by two-patch interactions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Lingyao Kong, Hua Tong, Hao Hu
For two-patch particles in two dimensions, we find that the coupling of anisotropic patchy interactions and the triangular lattice leads to novel phase behaviors. For asymmetric patch-patch (PP) and nonpatch-nonpatch (NN) interactions, the system has dual orientationally ordered phases of the same symmetry, intermediated by a nematic phase. Both phase transitions from the nematic phase to dual ordered phases are continuous and belong to the same universality class, and they lead to highly nonmonotonic variations of the nematic order parameter. The system becomes disordered at high temperature through another continuous transition. When the PP and NN interactions become symmetric, the system has subextensive ground-state entropy, and with increasing temperature it undergoes two Berezinskii-Kosterlitz-Thouless phase transitions, with a critical phase connecting a nematic phase and a disordered phase. These results open up new opportunities for designing patchy interactions to study orientational phase transitions and critical phenomena.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
7 pages, 6 figures
Design of a Josephson diode based on double magnetic impurities
New Submission | Superconductivity (cond-mat.supr-con) | 2025-09-05 20:00 EDT
Yu-Fei Sun, Yue Mao, Qing-Feng Sun
We theoretically propose a universal superconducting diode device based on double magnetic impurities which are coupled to the connection region of the Josephson junction. The positive and negative currents flowing across the junction can generate opposite magnetic fields, flipping the magnetic moment of the side magnetic impurity to the opposite directions, and in turn, the two impurities will have different impacts on the opposite currents. This results in the phenomenon that the positive and negative critical currents are unequal, referred to as the superconducting diode effect (SDE). Using the nonequilibrium Green’s function method (NEGF), we obtain the direction-dependent critical currents. We confirm the emergency of the SDE and demonstrate the dependence of the superconducting diode efficiency on a range of parameters including the magnitude, the direction, and the position of the magnetic moment. Besides, we systematically analyze the symmetry relations of the nonreciprocity in our system. Our proposal has high practicability by avoiding the demand on the external magnetic field, the Cooper pair momentum, and the spin-orbit coupling. Our approach opens up new possibilities for the development of nonreciprocal electronic circuits and provides an alternate perspective on the advancement of superconducting devices.
Superconductivity (cond-mat.supr-con)
11 pages, 6 figures
Phys. Rev. B 111, 054515 (2025)
Hubbard dimer physics and the magnetostructural transition in the correlated cluster material Nb$_3$Cl$_8$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Alberto Carta, Peter Mlkvik, Fabian Grahlow, Markus Ströbele, H.-Jürgen Meyer, Carl P. Romao, Nicola A. Spaldin, Claude Ederer
We present a combined computational and experimental study of Nb$ _3$ Cl$ _8$ , a correlated layered material containing Nb trimers, through the lens of competing intra- and intercluster interactions. Different proposed explanations for its magnetostructural transition such as charge disproportionation, antiferromagnetic quenching, and interlayer singlet formation are investigated in light of the various reported low-temperature structures. Our findings rule out the previously proposed charge-disproportionation, suggest an intricate interplay between Mott physics and the formation of interlayer singlets, and also hint at a possible explanation of the observed intratrimer scissoring distortion. We suggest that the physics of Nb$ _3$ Cl$ _8$ should be understood in the context of weakly coupled Hubbard dimers.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Band bending and zero-conductance resonances controlled by edge electric fields in zigzag silicene nanoribbons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Wei-Tao Lu, Qing-Feng Sun, Hong-Yu Tian, Ben-Hu Zhou, Hong-Mei Liu
We study the band structure and transport property of a zigzag silicene nanoribbon when the electric fields are applied to the edges. It is found that a band bending could be induced and controlled by the antisymmetric edge fields, which can be understood based on the wave functions of the edge states. The highest valence band and the lowest conduction band coexist in the band bending region. With the narrowing of edge potentials, the bending increases gradually. When the edge fields become symmetric, an asymmetric band gap at the Dirac points can be obtained due to the intrinsic spin-orbit interaction, suggesting a valley polarized quantum spin Hall state. The gap could reach a maximum value rapidly and then decrease slowly as the electric fields increase. Due to the combining effect of the band bending, band selective rule, and resonant states, many zero-conductance resonances and resonance peaks appear in different regions, which could be described by the Fano resonance effect. Furthermore, the band bending and zero-conductance resonances are robust against the Hubbard interaction. The Hubbard interaction could work as a spin-dependent edge field, together with the edge electric fields, leading to a spin-dependent band gap and various quantum phases such as metal and half-metal.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 10 figures
Phys. Rev. B 102, 125426 (2020)
Directed evolution effectively selects for DNA based physical reservoir computing networks capable of multiple tasks
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Tanmay Pandey, Petro Feketa, Jan Steinkühler
DNA and other biopolymers are being investigated as new computing substrates and alternative to silicon-based digital computers. However, the established top-down design of biomolecular interaction networks remains challenging and does not fully exploit biomolecular self-assembly capabilities. Outside of the field of computation directed evolution has been used as a tool for goal directed optimization of DNA sequences. Here, we propose integrating directed evolution with DNA-based reservoir computing to enable in-material optimization and adaptation. Simulations of colloidal beads networks connected via DNA strands demonstrate a physical reservoir capable of non-linear time-series prediction tasks, including Volterra series and Mackey-Glass chaotic dynamics. Reservoir computing performance, quantified by normalized mean squared error (NMSE), strongly depends on network topology, suggesting task-specific optimal network configurations. Implementing genetic algorithms to evolve DNA-encoded network connectivity effectively identified well-performing reservoir networks. Directed evolution improved reservoir performance across multiple tasks, outperforming random network selection. Remarkably, sequential training on distinct tasks resulted in reservoir populations maintaining performance on prior tasks. Our findings indicate DNA-bead networks offer sufficient complexity for reservoir computing, and that directed evolution robustly optimizes performance.
Soft Condensed Matter (cond-mat.soft), Disordered Systems and Neural Networks (cond-mat.dis-nn)
10 pages, 9 figures
Phase transitions in quantum dot-Majorana zero mode coupling systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
The magnetic doublet ground state (GS) of a quantum dot (QD) could be changed to a spin-singlet GS by coupling to a superconductor. In analogy, here we study the GS phase transitions in QD-Majorana zero mode (MZM) coupling systems: GS behaves phase transition versus intra-dot energy level and QD-MZM coupling strength. The phase diagrams of GS are obtained, for cases with and without Zeeman term. Along with the phase transition, we also study the change of spin feature and density of states. The properties of the phase transition are understood via a mean-field picture. Our study not only serves as an analogue to QD-superconductor phase transitions, but also gives alternative explanations on MZM-relevant experiments.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con)
18 pages, 7 figures
SciPost Phys. Core 8, 031 (2025)
Electrical control of crossed Andreev reflection and spin-valley switch in antiferromagnet/superconductor junctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
We study the subgap transport through the antiferromagnet/superconductor (AF/S) and antiferromagnet/superconductor/antiferromagnet (AF/S/AF) junctions controlled by electric field in a generic buckled honeycomb system, such as silicene, germanene, and stanene. In the present of electric field and antiferromagnetic exchange field, the spin-valley polarized half metallic phase can be achieved in the honeycomb system due to the spin-orbit coupling, which affords an opportunity to generate the pure crossed Andreev reflection (CAR). It is found that the pure CAR can be generated without local Andreev reflection (AR) and elastic cotunneling (EC) over a wide range of electric field. A spin-valley switch effect can be realized between the pure CAR and the pure EC by adjusting the electric field. The properties of AR process and CAR process strongly depend on the spin-valley polarized states. Our results suggest that the device can implement an electrical measurement of the CAR process and spin-valley switch.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con)
9 pages, 8 figures
Phys. Rev. B 104, 045418 (2021)
Orbital hybridization in graphene-based artificial atoms
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Yue Mao, Hui-Ying Ren, Xiao-Feng Zhou, Hao Sheng, Yun-Hao Xiao, Yu-Chen Zhuang, Ya-Ning Ren, Lin He, Qing-Feng Sun
Intraatomic orbital hybridization and interatomic bond formation are the two fundamental processes when real atoms are condensed to form matter. Artificial atoms mimic real atoms by demonstrating discrete energy levels attributable to quantum confinement. As such, they offer a solid-state analogue for simulating intraatomic orbital hybridization and interatomic bond formation. Signatures of interatomic bond formation has been extensively observed in various artificial atoms. However, direct evidence of the intraatomic orbital hybridization in the artificial atoms remains to be experimentally demonstrated. Here we, for the first time, realize the orbital hybridization in artificial atoms by altering the shape of the artificial atoms. The anisotropy of the confining potential gives rise to the hybridization between quasibound states with different orbital quantum numbers within the artificial atom. These hybridized orbits are directly visualized in real space in our experiment and are well reproduced by both numerical calculations and analytical derivations. Our study opens an avenue for designing artificial matter that cannot be accessed on real atoms through experiments. Moreover, the results obtained inspire the progressive control of quantum states in diverse systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
23 pages, 13 figures (+ supplementary materials 23 pages, 11 figures)
Nature 639, 73 (2025)
Tunneling Magnetoresistance Effect in Altermagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Yu-Fei Sun, Yue Mao, Yu-Chen Zhuang, Qing-Feng Sun
As an unconventional magnet, altermagnetism attracts great interest in condensed matter physics and applies a new research platform for the spintronics. Since the tunneling magnetoresistance (TMR) effect is an important research aspect in spintronics, we theoretically propose a universal altermagnetic sandwich device to achieve the TMR effect and investigate its transport properties. Using the nonequilibrium Green’s function method and the Landauer-Büttiker formula, we obtain the conductance and the TMR ratio. By systematically rotating the orientations of the altermagnet and spin, we investigate how the altermagnetic orientations affect the conductance and the TMR ratio, and comprehensively demonstrate the dependence of the conductance and the TMR ratio on a range of parameters in the system. By tuning the altermagnetism strength and the Fermi energy, as well as rotating the orientations in the altermagnet, the TMR ratio can reach a value of over 1000%. In addition, we analyze the detailed symmetry relations of the conductance and the TMR ratio in our system. Our approach provides a new design concept for the next-generation information technologies based on the altermagnetic platform, paving the way for the development of spintronics applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 7 figures
Spin-valley polarized edge states and quantum anomalous Hall states controlled by side potential in 2D honeycomb lattices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Wei-Tao Lu, Qing-Feng Sun, Yun-Fang Li, Hong-Yu Tian
Based on the tight-binding formalism, we study the effect of side potential on the spin and valley related electronic property of $ 2$ D honeycomb lattices with intrinsic spin-orbit coupling, such as silicene and germanene. The side potential is composed of potential field and exchange field applied on the boundaries of the zigzag nanoribbon. It is found that the side potential could greatly affect the helical edge states with different spin indices and the spin and valley are locked to each other. By adjusting the side potential and ribbon width, the system shows quantum spin-valley Hall effect, valley polarized quantum spin Hall effect, and spin polarized quantum anomalous Hall effect. Due to the side potential and the coupling of edge states in narrow ribbon, a band gap could be opened for specific spin and the time-reversal symmetry could be broken, leading to a spin polarized quantum anomalous Hall phase. Various kinds of spin-valley polarized edge states are formed at the two boundaries. Furthermore, the spin-valley polarized insulating states can be used to realize a perfect spin-valley switch.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
8 pages, 9 figures
Phys. Rev. B 104, 195419 (2021)
Physically Interpretable Descriptors Drive the Materials Design of Metal Hydrides for Hydrogen Storage
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Seong-Hoon Jang, Di Zhang, Hung Ba Tran, Xue Jia, Kiyoe Konno, Ryuhei Sato, Shin-ichi Orimo, and Hao Li
Designing metal hydrides for hydrogen storage remains a longstanding challenge due to the vast compositional space and complex structure-property relationships. Herein, for the first time, we present physically interpretable models for predicting two key performance metrics, gravimetric hydrogen density $ w$ and equilibrium pressure $ P_{\rm eq,RT}$ at room temperature, based on a minimal set of chemically meaningful descriptors. Using a rigorously curated dataset of $ 5,089$ metal hydride compositions from our recently developed Digital Hydrogen Platform (\it{DigHyd}) based on large-scale data mining from available experimental literature of solid-state hydrogen storage materials, we systematically constructed over $ 1.6$ million candidate models using combinations of scalar transformations and nonlinear link functions. The final closed-form models, derived from $ 2$ -$ 3$ descriptors each, achieve predictive accuracies on par with state-of-the-art machine learning methods, while maintaining full physical transparency. Strikingly, descriptor-based design maps generated from these models reveal a fundamental trade-off between $ w$ and $ P_{\rm eq,RT}$ : saline-type hydrides, composed of light electropositive elements, offer high $ w$ but low $ P_{\rm eq,RT}$ , whereas interstitial-type hydrides based on heavier electronegative transition metals show the opposite trend. Notably, Be-based systems, such as Be-Na alloys, emerge as rare candidates that simultaneously satisfy both performance metrics, attributed to the unique combination of light mass and high molar density for Be. Our models indicate that Be-based systems may offer renewed prospects for approaching these benchmarks. These results provide chemically intuitive guidelines for materials design and establish a scalable framework for the rational discovery of materials in complex chemical spaces.
Materials Science (cond-mat.mtrl-sci)
Thickness-Induced Topological Phase Transition Investigated by Helicity Dependent Photocurrent in $α$-Sn/CdTe(110)
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Tengfei Liu, Xiyu Hong, Zhe Li, Shenzhong Chen, Leyi Li, Xin-Yi Tang, Shuying Cheng, Yunfeng Lai, Yonghai Chen, Zhu Diao, Ke He, Qi-kun Xue, Jinling Yu
$ \alpha$ -Sn exhibits a rich topological phase diagram, yet experimental methods to tune and distinguish these phases remain limited. Here, we investigated the helicity-dependent photocurrent (HDPC) in $ \alpha$ -Sn films of varying thickness grown on CdTe(110) by molecular beam epitaxy. The HDPC of the 5 nm $ \alpha$ -Sn film shows an odd-function dependence on incident angle, whereas that of the 10 and 30 nm films exhibit an even-function dependence. Combined with high-resolution transmission electron microscopy (HR-TEM), point-group symmetry analysis, and first-principles calculations, it is revealed that a thickness-driven topological phase transition from a two dimensional (2D) to a three dimensional (3D) topological insulator occurs between 5 and 10 nm. These results demonstrate that HDPC serves as a sensitive diagnostic tool for topological phase transitions. The tunable electronic properties of $ \alpha$ -Sn(110) films enable thickness- and strain-mediated control of topological states, establishing a versatile platform for exploring emerging topological phenomena and developing spin-based devices.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
Moiré spintronics: Emergent phenomena, material realization and machine learning accelerating discovery
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Fengjun Zhuo, Zhenyu Dai, Hongxin Yang, Zhenxiang Cheng
Twisted van der Waals (vdW) materials have emerged as a promising platform for exploring the exotic quantum phenomena and engineering the novel material properties in two dimensions, which could bring revolutionary developments in spintronics. This Review aims at providing an overview of recent progress on emerging moiré spintronics in twisted vdW materials, with a particular focus on two-dimensional magnetic materials. After a brief introduction to the general features of twisted vdW materials, we discuss recent theoretical and experimental studies on stacking-dependent interlayer magnetism, non-collinear spin textures, moiré magnetic exchange interactions, moiré skyrmions and moiré magnons. We further highlight the ability to accelerate the discovery and design multifunctional materials for moiré spintronics with the assistance of machine learning. We conclude with the most pressing challenges and potential opportunities in this rapidly expanding field.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Magnetic behavior of $5d^1$ Re-based double perovskite Sr$_2$ZnReO$_6$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Muhammad Maikudi Isah, Biswajit Dalal, Xun Kang, Dario Fiore Mosca, Ifeanyi John Onuorah, Valerio Scagnoli, Pietro Bonfà, Roberto De Renzi, Alexei A. Belik, Cesare Franchini, Kazunari Yamaura, Samuele Sanna
The subtle interplay between spin-orbit coupling, exchange interactions, and cation ordering can lead to exotic magnetic states in transition-metal ions. We report a comprehensive study of the Re-based (5$ d^1$ ) ordered double perovskite oxide Sr$ _2$ ZnReO$ _6$ combining synchrotron x-ray diffraction (XRD), magnetic susceptibility, muon spin relaxation ($ \mu$ SR) measurements, and density functional theory (DFT) calculations. XRD reveals that Sr$ _2$ ZnReO$ _6$ crystallizes in the monoclinic structure (space group $ P2_1/n$ ) at low temperature. Magnetic susceptibility data indicate a transition below $ \sim$ 13 K, with $ M$ –$ H$ loops showing ferromagnetic-like hysteresis and an unusually high coercive field of 23 kOe at 2 K. Zero-field $ \mu$ SR measurements detect static and spatially disordered internal fields below $ T_M \simeq $ 12 K, consistent with a canted antiferromagnetic ground state determined by detailed DFT and force-theorem in Hubbard-I calculations. The reduced high-temperature effective moment ($ \sim0.76\mu_B$ ) and very small static moment ($ \lesssim 0.222\mu_B$ ) derived from $ \mu$ SR analysis and local-field simulations indicate a decisive role of spin-orbit coupling. Through a combined experimental and computational approach we unambiguously determine the canted antiferromagnetic order in Sr$ _2$ ZnReO$ _6$ , showing that a very small ordered moment coexists with an exceptionally large coercivity. These results underscore the crucial role of spin-orbit coupling and orbital ordering, providing new insights into magnetism in 5$ d^1$ double perovskites.
Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 5 figures, and 1 Table
Simulation of Lateral Impulse Induced Inertial Dilation at the Surface of a Vacuum-Exposed Granular Assembly
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Eric Frizzell, Christine Hartzell
We demonstrate for the first time that a lateral impulse experienced by a granular channel can induce an inertial bulk dilation over long distances across a granular medium with a mechanically free surface. The surface dilation requires zero overburden pressure (exposure to vacuum) and is precipitated by the passing of waves traveling barely above the sound speed (> Mach 1.05). We simulate this phenomenon using open source Soft Sphere Discrete Element Method (SSDEM) software. We prepare channels of monodisperse, cohesive spherical particles exposed to vacuum and modeled as Hertzian springs. We validate our model by recreating acoustic wave, strong shock, and shear dilation behavior. We then create shocks within the channel to determine the sensitivity of surface dilation to wave speed, wave type, initial packing fraction, and boundary effects. The shocks we create undergo a rapid decay in strength and appear to propagate as solitary waves that can be sustained across the channel. We find that an inertial surface dilation is induced by compressive solitary waves, is insensitive to channel length, increases with bed height, and increases substantially with initial packing fraction. A hard subsurface floor is required to maintain this wave over the entire channel. Free surface dilation induced by laterally propagating impulse loading could be implicated in the formation of Lunar Cold Spots, distal regions of low thermal inertia surrounding young craters on the Moon.
Soft Condensed Matter (cond-mat.soft), Space Physics (physics.space-ph)
Published in Granular Matter
Frizzell, Eric S., and Christine M. Hartzell. “Simulation of lateral impulse induced inertial dilation at the surface of a vacuum-exposed granular assembly.” Granular Matter 25.4 (2023): 75
Depletion-Induced Interactions Modulate Nanoscale Protein Diffusion in Polymeric Crowder Solutions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Michelle Dargasz, Nimmi Das Anthuparambil, Sebastian Retzbach, Anita Girelli, Sonja Timmermann, Johannes Möller, Wonhyuk Jo, Aliaksandr Lenonau, Agha Mohammad Raza, Maddalena Bin, Jaqueline Savelkouls, Iason Andronis, Frederik Unger, Felix Brausse, Jörg Hallmann, Ulrike Boesenberg, Jan-Etienne Pudell, Angel Rodriguez-Fernandez, James Wrigley, Roman Shayduk, Mohamed Youssef, Alexey Zozulya, Anders Madsen, Felix Lehmkühler, Fivos Perakis, Fajun Zhang, Frank Schreiber, Michael Paulus, Christian Gutt
Macromolecular crowding plays a crucial role in modulating protein dynamics in cellular and in vitro environments. Polymeric crowders such as dextran and Ficoll are known to induce entropic forces, including depletion interactions, that promote structural organization, but the nanoscale consequences for protein dynamics remain less well understood. Here, we employ megahertz X-ray photon correlation spectroscopy (MHz-XPCS) at the European XFEL to probe the dynamics of the protein ferritin in solutions containing sucrose, dextran, and Ficoll. We find that depletion-driven short-range attractions combined with long-range repulsions give rise to intermediate-range order (IRO) once the polysaccharide overlap concentration $ c^\ast$ is exceeded. These IRO features fluctuate on microsecond to millisecond timescales, strongly modulating the collective dynamics of ferritin. The magnitude of these effects depends sensitively on crowder type, concentration, and molecular weight. Normalizing the crowder concentration by $ c^\ast$ reveals scaling behavior in ferritin self-diffusion with a crossover near 2$ c^\ast$ , marking a transition from depletion-enhanced mobility to viscosity-dominated slowing. Our results demonstrate that bulk properties alone cannot account for protein dynamics in crowded solutions, underscoring the need to include polymer-specific interactions and depletion theory in models of crowded environments.
Soft Condensed Matter (cond-mat.soft)
Ergodicity and hydrodynamics: from quantum to classical spin systems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-05 20:00 EDT
Jiaozi Wang, Luca Capizzi, Dario Poletti, Leonardo Mazza
We show that in classical spin systems the precise nature of the late-time hydrodynamic tails of the autocorrelation functions of a generic observable is determined by (i) the dynamical critical exponent and (ii) the equilibrium thermodynamic properties of the corresponding observable. We provide numerical results for one- and two-dimensional systems and present theoretical considerations that only rely on the notion of ergodicity. Our result extends to the classical framework the relaxation-overlap inequality, first introduced in Capizzi et al. Phys. Rev. X 15, 011059 (2025)] for quantum many-body systems satisfying the eigenstate thermalization hypothesis.
Statistical Mechanics (cond-mat.stat-mech), Quantum Gases (cond-mat.quant-gas), Chaotic Dynamics (nlin.CD), Quantum Physics (quant-ph)
13 pages, 9 figures
Grain boundary energy models and boundary splitting
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Models of grain boundary energy are essential for predicting the behavior of polycrystalline materials. Typical models represent the minimum boundary energy as a function of macroscopic boundary parameters. An energy model may allow for boundary dissociation, i.e., for a further reduction of the overall energy by splitting a boundary into two boundaries parallel to the original one. Such splitting is prevented by constraining the energy model with inequalities opposite to the boundary wetting condition. The inequalities are applicable only to triplets of boundaries that match the assumed geometric configuration. Relationships connecting the parameters of such boundaries are derived, implications of the inequalities that prevent boundary splitting are considered, and an example energy model is shown to allow boundary decomposition. Knowing whether a given energy model permits boundary dissociation and which boundaries can be affected is important for evaluating its performance in polycrystal simulations.
Materials Science (cond-mat.mtrl-sci)
12 pages, 4 figures, 28 references
Shape spectra of elastic shells with surface-adsorbed semiflexible polymers
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Hadiya Abdul Hameed, Jaroslaw Paturej, Aykut Erbas
The shape of biological shells, such as cell nuclei, membranes, and vesicles, often deviates from a perfect sphere due to an interplay of complex interactions with a myriad of molecular structures. In particular, semiflexible biopolymers adsorbed to the surfaces of such shells seem to affect their morphological properties. While the effect of a single, long, semiflexible chain is relatively well characterized, the mechanisms by which a high density of such surface-adsorbed polymers can alter the morphology of a spherical, soft confinement, akin to biological shells, remain relatively poorly understood. Here, we use coarse-grained molecular dynamics simulations to investigate how surface adsorption of many semiflexible polymers affects the morphology of a pressurized bead-spring shell, which is spherical in the absence of these chains. By varying the attraction strength between the chains and the shell surface, chain concentration, and the polymerization degree of chains, we demonstrate that strong surface localization of the chains can induce severe shape distortions and shrinkage, depending on the chain length and concentration. Conversely, weak localization does not induce significant shape fluctuations, yet nematically ordered phases appear on the surface. Notably, these ordered phases lead to elliptic shell shapes for chains with sizes comparable to or longer than the radius of the confinement when the elastic shell is composed of extensible, harmonic bonds. Overall, our findings offer a strategy to control the shape of synthetic shells by manipulating peripheral localization and length of semiflexible polymers while suggesting a mechanism for non-spherical shapes appearing in some biological systems.
Soft Condensed Matter (cond-mat.soft), Computational Physics (physics.comp-ph)
11 pages, 5 figures Supplementary information, 10 pages, 10 figures
Emergence of quantum spin liquid and spin-flop phase in Kitaev antiferromagnets in a [111] magnetic field
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Shuai Liu, Hao Wu, Jinbin Li, Xiaoqun Wang, Qiang Luo
Kitaev magnets have emerged as pivotal systems for investigating frustrated magnetism, providing a unique platform to explore quantum phases governed by the interplay between bond-dependent anisotropy and external magnetic fields. However, the quantum phase diagrams, particularly near the dominant antiferromagnetic Kitaev regime, remain puzzling despite extensive studies. In this work, we perform unbiased exact diagonalization calculations of the Kitaev-$ \Gamma$ model in a [111] magnetic field on a $ C_{6}$ -symmetric 24-site cluster. By calculating the $ \mathbb{Z}_2$ flux density and the topological entanglement entropy, we reveal multiple phase transitions and identify signatures of both scalar and vector chiral orders in the intermediate-field regime between the Kitaev spin liquid and the polarized phase. As the negative $ \Gamma$ interaction increases, we discover a proximate quantum spin liquid featured by a three-peak specific heat and a spin-flop phase at a moderate magnetic field. Our findings provide insight into the field-induced intermediate phases in the antiferromagnetic Kitaev model and pave the way for the hunt for emergent phases in real materials.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
12 pages, 11 figures
Goos-Hanchen Shift with a rotating atomic superfluid in a ring
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-09-05 20:00 EDT
Ghaisud Din, Muqaddar Abbas, Pei Zhang
We investigate the Goos Hanchen shift of the transmitted probe and show that optomechanical interference in a ring Bose Einstein condensate provides a sensitive, rotation tunable beam shift response at ultralow optical powers. Without quantized circulation, conventional optomechanically induced transparency produces a strictly positive and bounded shift whose magnitude is governed primarily by cooperativity; small detuning offsets can introduce a weak, transient sign change consistent with a Fano type asymmetry, but the overall response remains limited. With circulation, the Bragg scattered mechanical side modes split, yielding a double transparency dispersion with steep dispersive flanks that strongly amplify the phase derivative and bias its sign. In this regime, the peak shift grows monotonically with control field strength, reflecting enhanced linearized coupling and increased transmission across the angular scan. At fixed power, the detuning dependence is decisive: the shift is maximized at the red sideband condition and diminishes away from resonance, tracking how effectively the scan samples the rotation split dispersive flanks. Increasing the winding number broadens the central absorption and steepens accessible phase gradients, further boosting the attainable shift. The protocol remains minimally invasive under experimentally realistic conditions, and interatomic interactions have a negligible influence on the transmission features that set the phase slope. These results identify circulation, control power, and cavity detuning as practical knobs for in situ control of the Goos Hanchen shift, enabling interferometric beam steering and phase gradient metrology in hybrid atom optomechanical platforms.
Quantum Gases (cond-mat.quant-gas)
14,11
Classical density functional theory for nanoparticle-laden droplets
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Melih Gül, Andrew J Archer, Benjamin D Goddard, Roland Roth
Droplets of a pure fluid, such as water, in an open container surrounded by gas, are thermodynamically unstable and evaporate quickly. In a recent paper [Archer et al. J. Chem. Phys. {\bf 159}, 194403 (2023)] we employed lattice density functional theory (DFT) to demonstrate that nanoparticles or solutes dissolved in a liquid droplet can make it thermodynamically stable against evaporation. In this study, we extend our model by using continuum DFT, which allows for a more accurate description of the fluid and nanoparticle density distributions within the droplet and enables us to consider size ratios between nanoparticles and solvent particles up to 10:1. While the results of the continuum DFT agrees well with those of our earlier lattice DFT findings, our approach here allows us to refine our understanding of the stability and structure of nanoparticle laden droplets. This is particularly relevant in light of the recent global COVID-19 pandemic, which has underscored the critical role of aerosol particles in virus transmission. Understanding the stability and lifetime of these viron-laden aerosols is crucial for assessing their impact on airborne disease spread.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
24 pages, 8 figures
Kinetic Random-Field Nonreciprocal Ising Model
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-05 20:00 EDT
We introduce and analyse the kinetic random-field nonreciprocal Ising model, which incorporates bimodal disorder along with pairwise nonreciprocal interactions between two different species. Using mean-field and effective-field theory, in combination with kinetic Monte Carlo simulations (3D Glauber dynamics), we identify a nonequilibrium tricritical (Bautin) point separating Hopf-type transitions (continuous) from saddle-node-of-limit-cycle (SNLC) transitions (discontinuous). For a weak random field which is less than a critical value, the onset of collective oscillations (the “swap” phase) occurs via a supercritical Hopf bifurcation, whereas for fields greater than the critical value, the transition is first-order (SNLC), exhibiting hysteresis and Binder-cumulant signatures. The finite-size scaling of the susceptibility is consistent with the distinct critical and discontinuous behaviour shown in the Hopf and SNLC regimes, respectively (effective exponents $ \approx1.96$ in the Hopf regime and $ \approx3.0$ in the SNLC regime). Additionally, in the first-order regime, the swap phase is sustained only above a threshold nonreciprocity, and this threshold increases monotonically with the disorder strength. We further identify a new droplet-induced swap phase in the larger field-strength region, which cycles eight different metastable states. A dynamical free-energy picture rationalises droplet nucleation as the mechanism for these cyclic jumps. Together, these results demonstrate how disorder and nonreciprocity combined generate rich nonequilibrium criticality, with implications for driven and active systems.
Statistical Mechanics (cond-mat.stat-mech)
Local structural disorder in crystalline materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Local positional disorder in soft, anharmonic materials has emerged as a central factor in shaping their electronic, vibrational, optical, and transport properties. Viewed mainly as a source of performance degradation, recent theoretical insights reveal that local disorder profoundly influences the electronic structure and phonon dynamics, without inducing deep electronic traps or non-radiative recombination pathways. In this work, we highlight advances in modeling local disorder using polymorphous and anharmonic frameworks, showing how these methods explain experimental observations and predict new trends. We emphasize the role of disorder in the breakdown of the phonon quasiparticle picture and in modulating electron-phonon and phonon-phonon interactions, particularly in soft, anharmonic phases of matter, with significant effects on electrical and thermal transport. We outline opportunities for integrating these insights into predictive modeling for energy materials and propose combining advanced first-principles methods with machine learning.
Materials Science (cond-mat.mtrl-sci)
Morphology Formation Pathways in Solution-Processed Perovskite Thin Films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
M. Majewski, O.J.J. Ronsin, J. Harting
The active layer in a perovskite solar cell is usually composed of a polycrystalline thin film. Fabrication of this layer by solution processing is a promising candidate for up-scaling to the mass market. However, the evolution of an evaporating and simultaneously crystallizing thin film is not yet fully understood. To contribute to the understanding of the formation of thin films, we develop a geometrical model that deals with the effect of the interplay between solvent evaporation and crystal growth on the dry film morphology. The possible film formation mechanisms are investigated, depending on the processing conditions. We find eleven formation pathways leading to four distinct morphologies. It is shown how these formation pathways can be utilized by adapting the process parameters to the material properties. Pinhole-free and flat films can be fabricated if the evaporation rate is high in comparison to the crystal growth rate. Alternatively, providing a high crystal number density on the substrate can lead to the desired film morphology at low drying rates. The generality of the model makes it applicable to any evaporating and simultaneously crystallizing thin film.
Materials Science (cond-mat.mtrl-sci)
Two-dimensional magnetic tunnel p-n junctions for low-power electronics
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Wenkai Zhu, Ziao Wang, Tiangui Hu, Zakhar R. Kudrynskyi, Tong Zhou, Zakhar D. Kovalyuk, Ce Hu, Hailong Lin, Xiaodong Li, Yongcheng Deng, Quanshan Lv, Lixia Zhao, Amalia Patane, Igor Zutic, Houzhi Zheng, Kaiyou Wang
For decades, semiconductors and their heterostructures have underpinned both fundamental and applied research across all areas of electronics. Two-dimensional, 2D (atomically thin) semiconductors have now the potential to push further the miniaturization of electronic components, enabling the development of more efficient electronics. Here, we report on a giant anomalous zero-bias spin voltage in magnetic tunnel junctions based on 2D materials. The generation, manipulation and detection of electron spin across a nanometer-thick magnetic tunnel junction do not require any applied bias. It is achieved by exploiting high-quality ferromagnetic/semiconductor interfaces and the asymmetric diffusion of spin-up/spin-down electrons across a semiconductor p-n junction. The large spin-voltage signal exceeds 30,000% and is far greater than the highest magnetoresistance signals reported to date. Our findings reveal unexplored opportunities to transform and amplify spin information for low-power electronics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
Quantum Hall Antidot as a Fractional Coulombmeter
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Mario Di Luca, Emily Hajigeorgiou, Zekang Zhou, Tengyan Feng, Kenji Watanabe, Takashi Taniguchi, Mitali Banerjee
The detection of fractionally charged quasiparticles, which arise in the fractional quantum Hall regime, is of fundamental importance for probing their exotic quantum properties. While electronic interferometers have been central to probe their statistical properties, their interpretation is often complicated by bulk-edge interactions. Antidots, potential hills in the quantum Hall regime, are particularly valuable in this context, as they overcome the geometric limitations of conventional designs and act as controlled impurities within a quantum point contact. Furthermore, antidots allow for quasiparticle charge detection through straightforward conductance measurements, replacing the need for more demanding techniques. In this work, we employ a gate-defined bilayer graphene antidot operating in the Coulomb-dominated regime to study quasiparticle tunneling in both integer and fractional quantum Hall states. We show that the gate-voltage period and the oscillation slope directly reveal the charge of tunneling quasiparticles, providing a practical method to measure fractional charge in graphene. Moreover, we report the first measurement of the $ e/3$ fractional charge in a graphene-based device. The simplicity and tunability of this design open a pathway to extend AD-based charge measurements to other van der Waals materials, establishing antidots as a powerful and broadly applicable platform to study the quantum Hall effect.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Nature of magnetic exchange interactions in kagome antiferromagnets FeGe and FeSn
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Magnetic exchange interactions (MEIs) in kagome magnets exhibit rich features due to the interplay of charge, spin, orbital and lattice degrees of freedom, giving rise to a variety of exotic quantum states. Through first-principles calculations, we systematically investigate the MEIs in kagome antiferromagnets FeGe and FeSn. While the antiferromagnetic order originates from the interlayer coupling between neighboring kagome layers, Fe atoms within each kagome layer couple ferromagnetically, driven by the competition between ferromagnetically favorable direct MEIs and antiferromagnetically favorable Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions. The stronger direct MEIs but weaker RKKY interactions in FeGe result in a substantially higher Néel temperature with respect to FeSn. Interestingly, the nearest neighboring exchange energy in both materials approximately linearly depends on the Fe-Fe bond length, so that moderate compressive strain can significantly enhance their Néel temperatures.
Materials Science (cond-mat.mtrl-sci)
18 pages, 9 figures
Interactions in Rare Earth Doped Nanoparticles: A Multi-Transition, Concentration, and Excitation Path Analysis
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-09-05 20:00 EDT
Pauline Perrin, Luiz Fernando Dos Santos, Diana Serrano, Alexey Tiranov, Jocelyn Achard, Alexandre Tallaire, Rogéria R. Gonçalves, Philippe Goldner
Understanding and modeling energy transfer mechanisms in rare-earth-doped nanomaterials is essential for advancing luminescent technologies used in bioimaging, optical thermometry, and solid-state lasers. In this work, we investigate the photoluminescence dynamics of Yb3+ and Er3+ ions in Y2O3 nanoparticles over a wide concentration range (0.5-17%), using both direct and upconversion excitation. Luminescence decays of green, red, and near-infrared transitions were measured and analyzed using a rate-equation model incorporating radiative and non-radiative processes, energy transfer mechanisms, and defect-related quenching. The model successfully reproduces experimental trends across most concentrations and excitation paths. This work provides a reliable and predictive framework for modeling energy transfer in rare-earth doped materials and offers valuable insights for optimizing photoluminescent properties in nanostructured systems.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
Hyperuniformity and conservation laws in non-equilibrium systems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-05 20:00 EDT
We demonstrate that hyperuniformity, the suppression of density fluctuations at large length scales, emerges generically from the interplay between conservation laws and non-equilibrium driving. The underlying mechanism for this emergence is analogous to self-organized criticality. Based on this understanding, we introduce four non-equilibrium models that consistently demonstrate hyperuniformity. Furthermore, we show that systems with an arbitrary number of conserved mass multipole moments exhibit an arbitrary strong tunable hyperuniform scaling, with the structure factor following $ S(k) \sim k^m$ , where $ m$ is set by the number of conserved multipoles. Finally, we find that hyperuniformity arising from a combination of conserved noise and partially conserved average motion is not robust against non-linear perturbations. These results highlight the central role of conservation laws in stabilizing hyperuniformity and reveal a unifying mechanism for its emergence in non-equilibrium systems.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
25 pages, 5 figures
Many-Body Rashba Spin-Orbit Interaction and Exciton Spin Relaxation in Atomically Thin Semiconductor Structures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Henry Mittenzwey, Andreas Knorr
We propose a previously unexplored spin-orbit interaction mechanism by establishing a mesoscopic many-particle Rashba Hamiltonian. In lowest order, this Hamiltonian self-consistently describes exciton spin relaxation in monolayer transition metal dichalcogenides (TMDC) due to local electric fields caused by spatial asymmetries in the dielectric environment. For a monolayer MoSe$ _2$ on a SiO$ _2$ substrate above 77,K showing a meV bright-dark splitting, the local electric field causes fast intravalley spin relaxation on a sub-picosecond timescale, whereas it is negligible for other TMDCs with larger bright-dark splitting.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Thermodynamic Basis of Sugar-Dependent Polymer Stabilization: Informing Biologic Formulation Design
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Praveen Muralikrishnan, Jonathan W. P. Zajac, Caryn L. Heldt, Sarah L. Perry, Sapna Sarupria
The stabilization of macromolecules is fundamental to developing biological formulations, such as vaccines and protein therapeutics. In this study, we employ coarse grained polymer models to investigate the impact of four sugars: {\alpha}-glucose, {\beta}-fructose, trehalose, and sucrose on macromolecule stability. Free energy decomposition and preferential interaction analysis indicate that polymer-sugar interactions favor folding at low concentrations while driving unfolding at higher concentrations. In contrast, the polymer-solvent soft interaction entropy consistently favors unfolding across all sugar concentrations under study. At low sugar concentrations, polymer-solvent interactions predominantly govern stabilization, whereas at higher concentrations, entropic penalties dictate polymer stability. Local mixing entropy demonstrates that binary sugar mixtures introduce entropic contributions that preferentially stabilize the folded state. These findings contribute to a more nuanced understanding of sugar-based excipient stabilization mechanisms, offering guidance for the rational design of stable biological formulations.
Soft Condensed Matter (cond-mat.soft)
Specific features of the $π$-electron spectrum of narrow achiral $(2m,m)$ nanoribbons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
On the basis of the Su-Schrieffer-Heeger-Hückel-type Hamiltonian, we consider the tight-binding eigenvalue problem for a sequence of pyrene molecules forming a narrow $ (2m,m)$ graphene nanoribbon. Specific features of the corresponding dispersion relation are analyzed and illustrated with several examples. It is shown that the $ \pi$ -electron spectrum of the pyrene oligomer includes local states, in contrast to the spectrum of linear acene, which consists only of extended states. We analyze and illustrate the difference in the behavior of
the electron density distribution for extended and local electronic states. Explicit analytic expressions for the Green’s function coefficients of the pyrene molecule are also presented.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
The Non-commutative Spaces of Higher-Order Networks of Bach’s Solo Violin Compositions: Dimension, Curvature, and Distance through the Spectral Triplet
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-05 20:00 EDT
Our work is concerned with simplicial complexes that describe higher-order interactions in real complex systems. This description allows to go beyond the pairwise node-to-node representation that simple networks provide and to capture a hierarchy of interactions of different orders. The prime contribution of this work is the introduction of geometric measures for these simplicial complexes. We do so by noting the non-commutativity of the algebra associated with their matrix representations and consequently we bring to bear the spectral triplet formalism of Connes on these structures and then notions of associated dimensions, curvature, and distance can be computed to serve as characterizing features in addition to known topological metrics.
Statistical Mechanics (cond-mat.stat-mech), Applied Physics (physics.app-ph), Computational Physics (physics.comp-ph), Data Analysis, Statistics and Probability (physics.data-an)
Control of lumen morphology by lateral and basal cell surfaces
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Chandraniva Guha Ray, Markus Mukenhirn, Alf Honigmann, Pierre A. Haas
Across development, the morphology of fluid-filled lumina enclosed by epithelial tissues arises from an interplay of lumen pressure, mechanics of the cell cortex, and cell-cell adhesion. Here, we explore the mechanical basis for the control of this interplay using the shape space of MDCK cysts and the instability of their apical surfaces under tight junction perturbations [Mukenhirn et al., Dev. Cell 59, 2886 (2024)]. We discover that the cysts respond to these perturbations by significantly modulating their lateral and basal tensions, in addition to the known modulations of pressure and apical belt tension. We develop a mean-field three-dimensional vertex model of these cysts that reproduces the experimental shape instability quantitatively. This reveals that the observed increase of lateral contractility is a cellular response that counters the instability. Our work thus shows how regulation of the mechanics of all cell surfaces conspires to control lumen morphology.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph), Tissues and Organs (q-bio.TO)
13 pages, 5 figures
In-situ profiling of pressure-induced exciton traps in suspended MoS$_2$ monolayers
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Leonard Geilen, Lukas Schleicher, Alexander Musta, Benedict Brouwer, Eva M. Weig, Alexander Holleitner, Anne Rodriguez
We demonstrate the in-situ read-out of the spatial profile of suspended MoS$ _2$ monolayers hosted on substrates with nano-structured holes. As the profiles are spatially bent, the suspended MoS$ _2$ monolayers act as exciton traps with tunable luminescence intensity and energy. The tunability is realized by controlling the environmental pressure on the monolayers, which allows to control hundreds of suspended MoS$ _2$ monolayers on a single substrate. The in-situ read-out is based on Fabry-Pérot interferences and a model of the corresponding reflectance contrast maps of the investigated monolayers.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Forced silo discharge: Simulation and theory
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-09-05 20:00 EDT
Luis. A. Pugnaloni, Marcos A. Madrid, J. R. Darias
We study, through discrete element simulations, the discharge of granular materials through a circular orifice on the base of a cylindrical silo forced by a surcharge. At the beginning of the discharge, for a high granular column, the flow rate $ Q_{\rm ini}$ scales as in the Beverloo equation for free discharge. However, we find that the flow rate $ Q_{\rm end}$ attained at the end of the forced discharge scales as $ \sqrt{\rho_b P}D_o^3/D_s$ , with $ \rho_b$ the bulk density, $ P$ the pressure applied by the overweight, $ D_o$ the orifice diameter and $ D_s$ the silo diameter. We use the work$ -$ energy theorem to formulate an equation for the flow rate $ Q_{\rm end}$ that predicts the scalings only in part. We discuss the new challenges offered by the phenomenology of strongly forced granular flows.
Soft Condensed Matter (cond-mat.soft)
14 pages, 12 figures
Chiral Graviton Theory of Fractional Quantum Hall States
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-09-05 20:00 EDT
Recent polarized Raman scattering experiments indicate that fractional quantum Hall systems host a chiral spin-2 neutral collective mode, the long-wavelength limit of the magnetoroton, which behaves as a condensed-matter graviton. We present a nonlinear, gauge-invariant effective theory by gauging area-preserving diffeomorphisms (APDs) with a unimodular spatial metric as the gauge field. A Stueckelberg construction introduces an APD-invariant local potential that aligns the dynamical metric with a reference geometry, opening a tunable gap while preserving gauge redundancy. Together with a geometric Maxwell kinetic sector and the Wen-Zee and gravitational Chern-Simons terms, the theory yields a gapped chiral spin-2 excitation consistent with universal long-wavelength constraints. The tunable gap emerges naturally from symmetry and provides a route to an isotropic-nematic quantum critical point where the spin-2 mode softens. We further establish a linear dictionary to quadrupolar deformations in composite Fermi liquid bosonization, and outline applications to fractional Chern insulators as well as higher-dimensional generalizations. Finally, the approach can be extended to non-Abelian fractional quantum Hall states, capturing both spin-2 and spin-3/2 neutral modes.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), High Energy Physics - Theory (hep-th)
58 pages
Unoccupied bands in the molybdenum dichalcogenides MoS$_2$, MoSe$_2$, and MoTe$_2$
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
J. Jobst, E. E. Krasovskii, R. Ribeiro, T. A. de Jong, C. R. Dean, R. M. Tromp, S. J. van der Molen
We present angle-resolved reflected electron spectroscopy (ARRES) data for the three molybdenum-based transition metal dichalcogenides (TMDs) \mos, \mose, and \mote. To follow the changes as the series moves from S to Se to Te in more detail, we determine accurate IV-spectra for monolayers and bulk TMDs. These experimental data sets are then compared with theoretical predictions for both the unoccupied band structure and the scattering density of states. We find good agreement, especially for lower energies where inelastic effects are relatively unimportant. Furthermore, we identify a series of interlayer resonances for which the dependence of the hybridization effects on the layer count is observed. Although these resonances bear similarity to interlayer resonances in hBN and graphene, they differ in their character, being dominated by unoccupied $ d$ -states of the chalcogen-atoms. The unoccupied states studied and analyzed here play a key role in all processes that require an electron to temporarily reside in a state above the vacuum level, such as in photoemission and secondary electron emission experiments.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
The influence of the Casimir effect on the binding potential for 3D wetting
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-09-05 20:00 EDT
Alessio Squarcini, José M. Romero-Enrique, Andrew O. Parry
We provide comprehensive details of how a previously overlooked entropic, or low temperature Casimir contribution, $ W_C$ , to the total binding potential for 3D short-ranged wetting may be determined from a microscopic Landau-Ginzburg-Wilson Hamiltonian. The entropic contribution comes from the many microscopic configurations corresponding to a given interfacial one, which arise from bulk-like fluctuations about the mean-field (MF) constrained profile, and adds to the usual MF contribution $ W_{MF}$ . We determine the functional dependence of $ W_C$ on the interface (and wall) shape using a boundary integral method which can be cast as a diagrammatic expansion with each diagram corresponding to successively higher-order exponentially decaying contributions. The decay of $ W_C$ is qualitatively different for first-order and critical wetting with the change in form occurring at the MF tricritical point. Including the Casimir contribution to the binding potential preserves the global surface phase diagram but changes, radically, predictions for fluctuation effects at first-order and tricritical wetting, even when capillary-wave fluctuations are not considered.
Statistical Mechanics (cond-mat.stat-mech), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Soft Condensed Matter (cond-mat.soft)
29 pages, 3 figures
Zero and Nonzero Energy Majorana Modes in an Extended Kitaev Chain
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Mohammad Ghuneim, Raditya Weda Bomantara
This paper studies an extended Kitaev chain with three sublattices per unit cell. This extended version is obtained by hybridizing a modified Su-Schrieffer-Heeger model featuring trimerized unit cells with the standard Kitaev chain, resulting in a hexamer structure on the Majorana basis. Due to the interplay between the sublattice configuration and the $ p$ -wave superconducting pairing, a rich structure of edge modes beyond the expected Majorana zero modes is obtained. The various Majorana edge modes are further found to demonstrate considerable robustness against some generic perturbations and disorder. The presence of robust Majorana edge modes beyond their zero energy variations potentially offers a step forward in the ongoing efforts to unambiguously detect Majorana modes in experiments.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Comments are welcome
Zero modes and index theorems for non-Hermitian Dirac fermions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-09-05 20:00 EDT
Dirac fermions, subject to external magnetic fields and in the presence of mass orders that assume topologically nontrivial spatial textures such as domain-wall and vortices, for example, bind robust mid-gap states at zero-energy, the number of which is governed by the Aharonov-Casher and Jackiw-Rebbi or Jackiw-Rossi index theorems, respectively. Here I extend the jurisdiction of these prominent index theorems to Lorentz invariant non-Hermitian (NH) Dirac operators, constructed by augmenting the celebrated Dirac Hamiltonian by a masslike anti-Hermitian operator that also scales linearly with momentum. The resulting NH Dirac operator manifests real eigenvalues over an extended NH parameter regime, characterized by a real effective Fermi velocity for NH Dirac fermions. From the explicit solutions of the zero-energy bound states, I show that in the presence of external magnetic fields of arbitrary shape such modes always exist when the system encloses a finite number of magnetic flux quanta, while in the presence of spatially non-trivial textures of the mass orders localized zero-energy modes can only be found in the spectrum when the effective Fermi velocity for NH Dirac fermions is real. These findings pave a concrete route to realize nucleation of competing orders from the topologically robust zero-energy manifold in NH or open Dirac systems. Possible experimental setups to test these predictions are discussed.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th)
11 Pages, No figures