CMP Journal 2025-04-17
Statistics
Nature Materials: 2
Nature Nanotechnology: 3
Physical Review Letters: 3
Physical Review X: 2
arXiv: 58
Nature Materials
Bioinstructive scaffolds enhance stem cell engraftment for functional tissue regeneration
Original Paper | Biomaterials - cells | 2025-04-16 20:00 EDT
Di Wu, Ioannis Eugenis, Caroline Hu, Soochi Kim, Abhijnya Kanugovi, Shouzheng Yue, Joshua R. Wheeler, Iman Fathali, Sonali Feeley, Joseph B. Shrager, Ngan F. Huang, Thomas A. Rando
Stem cell therapy is a promising approach for tissue regeneration after traumatic injury, yet current applications are limited by inadequate control over the fate of stem cells after transplantation. Here we introduce a bioconstruct engineered for the staged release of growth factors, tailored to direct different phases of muscle regeneration. The bioconstruct is composed of a decellularized extracellular matrix containing polymeric nanocapsules sequentially releasing basic fibroblast growth factor and insulin-like growth factor 1, which promote the proliferation and differentiation of muscle stem cells, respectively. When applied to a volumetric muscle loss defect in an animal model, the bioconstruct enhances myofibre formation, angiogenesis, innervation and functional restoration. Further, it promotes functional muscle formation with human or aged murine muscle stem cells, highlighting the translational potential of this bioconstruct. Overall, these results highlight the potential of bioconstructs with orchestrated growth factor release for stem cell therapies in traumatic injury.
Biomaterials - cells, Nanoparticles, Protein delivery, Tissue engineering
Immune-compatible designs of semiconducting polymers for bioelectronics with suppressed foreign-body response
Original Paper | Biomedical engineering | 2025-04-16 20:00 EDT
Nan Li, Seounghun Kang, Zhichang Liu, Shinya Wai, Zhe Cheng, Yahao Dai, Ani Solanki, Songsong Li, Yang Li, Joseph Strzalka, Michael J. V. White, Yun-Hi Kim, Bozhi Tian, Jeffrey A. Hubbell, Sihong Wang
One of the greatest obstacles to achieving implantable electronics with long-term functionality and minimized inflammatory reactions is the immune-mediated foreign-body response (FBR). Recently, semiconducting polymers with mixed electron-ion conductivity have been demonstrated as promising candidates to achieve direct electrical interfacing on bio-tissues. However, there is limited understanding of their immune compatibility in vivo, and strategies for minimizing the FBR through molecular design remain underexplored. Here we introduce a set of molecular design strategies for enhancing the immune compatibility of semiconducting polymers. Specifically, we show that selenophene, when incorporated in the backbone, can mitigate the FBR by suppressing macrophage activation. In addition, side-chain functionalization with immunomodulatory groups decreases the FBR further by downregulating the expression of inflammatory biomarkers. Together, our synthesized polymers achieve suppression of the FBR by as much as 68% (as indicated by the collagen density). In the meantime, these immune-compatible designs still provide a high charge-carrier mobility of around 1 cm2 V-1 s-1. We anticipate that such immune-compatible design principles can be translated to a variety of conjugated polymers to suppress the FBR for implantable applications.
Biomedical engineering, Electronic devices, Implants, Polymers
Nature Nanotechnology
Piracetam shapes wide-bandgap perovskite crystals for scalable perovskite tandems
Original Paper | Devices for energy harvesting | 2025-04-16 20:00 EDT
Shiqiang Fu, Shun Zhou, Weiwei Meng, Guang Li, Kailian Dong, Dexin Pu, Jin Zhou, Chen Wang, Hongling Guan, Wenlong Shao, Lishuai Huang, Zhenhuang Su, Cheng Wang, Guoyi Chen, Peng Jia, Jiahao Wang, Zuxiong Xu, Xingyu Gao, Hengjiang Cong, Ti Wang, Chuanxiao Xiao, Guojia Fang, Weijun Ke
All-perovskite tandem solar cells (TSCs) offer exceptional performance and versatile applicability. However, a significant challenge persists in bridging the power conversion efficiency (PCE) gap between small- and large-area (>1 cm2) devices, which presents a formidable barrier to the commercialization of all-perovskite TSCs. Here we introduce a specialized crystal-modifying agent, piracetam, tailored for wide-bandgap perovskites, homogenizing top wide-bandgap subcells and enabling the construction of efficient large-area TSCs. Piracetam, featuring amide and pyrrolidone moieties, initially modulates perovskite nucleation, resulting in large-sized grains, preferred (110) orientation, enhanced crystallinity and uniform optoelectronic properties. During the subsequent annealing process, it further eliminates residual PbI2 and facilitates the formation of one-dimensional (Pi)PbI3 (Pi = piracetam) perovskite nanoneedles at the grain boundaries and surfaces. Consequently, single-junction 1.77 eV-bandgap solar cells achieve a certified open-circuit voltage of 1.36 V and a PCE of 20.35%. Furthermore, our monolithic two-terminal all-perovskite TSCs, with aperture areas of 0.07 cm2 and 1.02 cm2, yield PCEs of 28.71% (stabilized 28.55%, certified 28.13%) and 28.20% (stabilized 28.05%, certified 27.30%), respectively, demonstrating a minimal PCE loss of 0.51% when transitioning from small-area to large-area devices. In addition, piracetam demonstrates broad applicability across different perovskite compositions, increasing the PCE from 23.56% to 25.71% for single-junction 1.56 eV-bandgap counterparts. This method thus provides an effective pathway for scalable and efficient all-perovskite TSCs.
Devices for energy harvesting, Materials for devices
Electrosynthesis of pure urea from pretreated flue gas in a proton-limited environment established in a porous solid-state electrolyte electrolyser
Original Paper | Electrocatalysis | 2025-04-16 20:00 EDT
Yan-Chen Liu, Jia-Run Huang, Hao-Lin Zhu, Xiao-Feng Qiu, Can Yu, Xiao-Ming Chen, Pei-Qin Liao
The electrosynthesis of pure urea via the co-reduction of CO2 and N2 remains challenging. Here we show that a proton-limited environment established in an electrolyser equipped with porous solid-state electrolyte, devoid of an aqueous electrolyte, can suppress the hydrogen evolution reaction and excessive hydrogenation of N2 to ammonia. This can instead be conducive to the C-N coupling of *CO2 with *NHNH (the intermediate from the semi-hydrogenation of N2), thereby facilitating the production of urea. By using nanosheets of an ultrathin two-dimensional metal-azolate framework with cyclic heterotrimetal clusters as catalyst, the Faradaic efficiency of urea production from pretreated flue gas (which contains mainly 85% N2 and 15% CO2) is as high as 65.5%, and no ammonia and other liquid products were generated. At a low cell voltage of 2.0 V, the current can reach 100 mA, and the urea production rate is as high as 5.07 g gcat-1 h-1 or 84.4 mmol gcat-1 h-1. Notably, it can continuously produce 6.2 wt% pure urea aqueous solution for at least 30 h, and about 1.24 g pure urea solid was obtained. The use of pretreated flue gas as a direct feedstock significantly reduces input costs, and the high reaction rate and selectivity contribute to a reduction in system scale and operational costs.
Electrocatalysis, Organometallic chemistry
On-demand formation of Lewis bases for efficient and stable perovskite solar cells
Original Paper | Devices for energy harvesting | 2025-04-16 20:00 EDT
Sheng Fu, Nannan Sun, Hao Chen, Cheng Liu, Xiaoming Wang, You Li, Abasi Abudulimu, Yuanze Xu, Shipathi Ramakrishnan, Chongwen Li, Yi Yang, Haoyue Wan, Zixu Huang, Yeming Xian, Yifan Yin, Tingting Zhu, Haoran Chen, Amirhossein Rahimi, Muhammad Mohsin Saeed, Yugang Zhang, Qiuming Yu, David S. Ginger, Randy J. Ellingson, Bin Chen, Zhaoning Song, Mercouri G. Kanatzidis, Edward H. Sargent, Yanfa Yan
In the fabrication of FAPbI3-based perovskite solar cells, Lewis bases play a crucial role in facilitating the formation of the desired photovoltaic α-phase. However, an inherent contradiction exists in their role: they must strongly bind to stabilize the intermediate δ-phase, yet weakly bind for rapid removal to enable phase transition and grain growth. To resolve this conflict, we introduced an on-demand Lewis base molecule formation strategy. This approach utilized Lewis-acid-containing organic salts as synthesis additives, which deprotonated to generate Lewis bases precisely when needed and could be reprotonated back to salts for rapid removal once their role is fulfilled. This method promoted the optimal crystallization of α-phase FAPbI3 perovskite films, ensuring the uniform vertical distribution of A-site cations, larger grain sizes and fewer voids at buried interfaces. Perovskite solar cells incorporating semicarbazide hydrochloride achieved an efficiency of 26.1%, with a National Renewable Energy Laboratory-certified quasi-steady-state efficiency of 25.33%. These cells retained 96% of their initial efficiency after 1,000 h of operation at 85 °C under maximum power point tracking. Additionally, mini-modules with an aperture area of 11.52 cm2 reached an efficiency of 21.47%. This strategy is broadly applicable to all Lewis-acid-containing organic salts with low acid dissociation constants and offers a universal approach to enhance the performance of perovskite solar cells and modules.
Devices for energy harvesting, Electronic devices
Physical Review Letters
Editorial: Celebrating the First Century of Quantum Physics and Preparing for the Next One
| 2025-04-16 06:00 EDT
Dagmar Bruß
Phys. Rev. Lett. 134, 150001 (2025)
Cooling the Shock: New Supernova Constraints on Dark Photons
Research article | Novae & supernovae | 2025-04-16 06:00 EDT
Andrea Caputo, Hans-Thomas Janka, Georg Raffelt, and Seokhoon Yun
During the accretion phase of a core-collapse supernova (SN), dark-photon (DP) cooling can be largest in the gain layer below the stalled shock wave. In this way, it could counteract the usual shock rejuvenation by neutrino energy deposition and thus prevent the explosion. This peculiar energy-loss profile derives from the resonant nature of DP production. The largest cooling and thus strongest constraints obtain for DP masses of 0.1–0.4 MeV, a range corresponding to the photon plasma mass in the gain region. Electron-capture supernovae, once observationally unambiguously identified, could provide strong bounds even down to nearly 0.01 MeV. For a coupling strength so small that neutrino-driven explosions are expected to survive, the DP cooling of the core is too small to modify the neutrino signal, i.e., our new argument supersedes the traditional SN1987A cooling bound.
Phys. Rev. Lett. 134, 151002 (2025)
Novae & supernovae, Particle astrophysics, Particle mixing & oscillations, Hypothetical gauge bosons
Laminar-Turbulent Patterns in Shear Flows: Evasion of Tipping, Saddle-Loop Bifurcation, and Log Scaling of the Turbulent Fraction
Research article | Bifurcations | 2025-04-16 06:00 EDT
Pavan V. Kashyap, Juan F. Marín, Yohann Duguet, and Olivier Dauchot
Spatial pattern formation can be a signal for tipping points and abrupt transitions in complex systems. In wall shear flows, the homogeneous turbulent state is disconnected from the laminar one and disappears in a tipping catastrophe scenario. It, however, linearly destabilizes before tipping, giving rise to laminar-turbulent banded patterns. The subcritical transition to turbulence is thus a promising candidate for investigating the evasion of tipping and its consequences in a well-controlled setting. To do so, we analyze a one-dimensional two-scalar fields advection diffusion reaction model of the transition. We characterize the multistability of the nonlinear solutions emerging from the instability and show that the pattern wavelength is selected by turbulent fluctuations. At lower Reynolds numbers, the pattern follows a cascade of destabilizations toward larger and larger, eventually infinite wavelengths. In that limit, the periodic limit cycle associated with the spatial pattern hits the laminar fixed point, resulting in a saddle loop, also called homoclinic, global bifurcation and the emergence of solitary pulse solutions. This saddle-loop scenario predicts a logarithmic divergence of the wavelength, which captures available experimental and numerical data.
Phys. Rev. Lett. 134, 154001 (2025)
Bifurcations, Pattern formation, Shear flows, Transition to turbulence
Physical Review X
Accuracy Guarantees and Quantum Advantage in Analog Open Quantum Simulation with and without Noise
Research article | Open quantum systems & decoherence | 2025-04-16 06:00 EDT
Vikram Kashyap, Georgios Styliaris, Sara Mouradian, J. Ignacio Cirac, and Rahul Trivedi
Quantum simulators can efficiently solve dissipative many-body problems that are intractable for classical computers, even with noise, thus establishing a robust quantum advantage for studying open quantum systems.
Phys. Rev. X 15, 021017 (2025)
Open quantum systems & decoherence, Quantum computing models, Quantum simulation
Electronic Nematicity in Interface Superconducting $\mathrm{LAO}/\mathrm{KTO}(111)$
Research article | Pair density wave | 2025-04-16 06:00 EDT
X. B. Cheng, M. Zhang, Y. Q. Sun, G. F. Chen, M. Qin, T. S. Ren, X. S. Cao, Y. W. Xie, and J. Wu
The discovery of nematic superconductivity in a lanthanum aluminate/potassium tantalate heterostructure suggests a deep connection between electronic nematicity and unconventional superconductivity.
Phys. Rev. X 15, 021018 (2025)
Pair density wave, Pairing mechanisms, Superconducting fluctuations, Superconductivity, Strongly correlated systems
arXiv
Transmission of low energy electrons through a polyethylene terephthalate 800-nm diameter nanocapillary
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Li Pengfei (1 and 2), Liu Wanqi (1), Ha Shuai (2), Pan Yuzhou (2), Fan Xuhong (2), Du Zhanhui (2), Wan Chengliang (2), Cui Ying (2), Yao Ke (3 and 4), Ma Yue (5), Yang Zhihu (6), Shao Caojie (6), Reinhold Schuch (7), Lu Di (8), Song Yushou (1), Zhang Hongqiang (2), Chen Ximeng (2), ((1) College of Nuclear Science and Technology, Harbin Engineering University, Harbin, China, (2) School of Nuclear Science and Technology, Lanzhou University, Lanzhou, China, (3) Institute of Modern Physics, Fudan University, Shanghai, China, (4) Key Laboratory of Nuclear Physics and Ion-Beam Application (MOE), Fudan University, Shanghai, China, (5) RIKEN Nishina Center, RIKEN, Wako, Japan, (6) Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China, (7) Physics Department, Stockholm University, Stockholm, Sweden, (8) Department of Physics, University of Gothenburg, Gothenburg, Sweden)
The transmission of 2-keV electrons through a polyethylene terephthalate (PET) nanocapillary with a diameter of 800 nm and a length of 10 {\mu}m is studied. The transmitted electrons are detected using a microchannel plate (MCP) with a phosphor screen. It is found that the transmission rate for the transmitted electrons at the incident energy can reach up to 10% for an aligned capillary in the beam direction, but drops to less than 1% when the tilt angle exceeds the geometrically allowable angle. The transmitted electrons with the incident energy do not move with changes in the tilt angle, so the incident electrons are not guided in the insulating capillary, which is different from the behavior of positive ions. In the final stage of transmission, the angular distribution of the transmitted electrons within the geometrically allowable angle splits into two peaks along the observation angle perpendicular to the tilt angle. The time evolution of the transmitted complete angular distribution shows that when the beam is turned on, the transmission profile forms a single peak. As the incident charge and time accumulate, the transmission profile begins to stretch in the plane perpendicular to the tilt angle and gradually splits into two peaks. When the tilt angle of the nanocapillary exceeds the geometrically allowable angle, this splitting tends to disappear. Simulation of charge deposition in the capillary directly exposed to the beam indicates the formation of positive charge patches, which are not conducive to guiding, unlike positive ions. Based on the simulation results, we can explain our data and discuss the possible reasons for the splitting of the transmission angular profiles.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Instability of the critical Ngai’s coupling and two-boson mechanism in metals
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
We study the properties of a Fermi liquid coupled to a quantum critical boson via the two-boson interaction known as Ngai’s coupling. We find that the original quantum critical point is generally unstable, resulting in a finite-momentum spatially modulated state unless two conditions are satisfied: (i) the critical boson is polar and transverse, and (ii) the ratio of the Fermi velocity to the transverse-boson velocity is sufficiently large. If these conditions hold and the uniform state remains stable, we demonstrate that the system enters a strong-coupling regime below a certain energy scale. In this regime, we discuss a self-consistent solution at criticality in two-dimensional systems and show that the critical boson field develops a nontrivial anomalous dimension, $ \eta=1/2$ . Our findings highlight the significant role of two-boson coupling in critical theories, challenging the conventional view that its effects are subdominant to linear coupling.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), High Energy Physics - Theory (hep-th)
4 pages + 14 pages of extensive supplemental materials are attached
Probing Quantum Anomalous Hall States in Twisted Bilayer WSe2 via Attractive Polaron Spectroscopy
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
Beini Gao, Mahdi Ghafariasl, Mahmoud Jalali Mehrabad, Tsung-Sheng Huang, Lifu Zhang, Deric Session, Pranshoo Upadhyay, Rundong Ma, Ghadah Alshalan, Daniel Gustavo Suárez Forero, Supratik Sarkar, Suji Park, Houk Jang, Kenji Watanabe, Takashi Taniguchi, Ming Xie, You Zhou, Mohammad Hafezi
Moiré superlattices in semiconductors are predicted to exhibit a rich variety of interaction-induced topological states. However, experimental demonstrations of such topological states, apart from MoTe2 superlattices, have remained scarce. Here, we report the first optical detection of quantum anomalous Hall (QAH) states in twisted WSe2 homobilayer (tWSe2). Specifically, we employ polarization-resolved attractive polaron spectroscopy on a dual-gated, 2 degree tWSe2 and observe direct signatures of spontaneous time-reversal symmetry breaking at hole filling {\nu} = 1. Together with a Chern number (C) measurement via Streda formula analysis, we identify this magnetized state as a topological state, characterized by C = 1. Furthermore, we demonstrate that these topological and magnetic properties are tunable via a finite displacement field, between a QAH ferromagnetic state and an antiferromagnetic state. Our findings position tWSe2 as a highly versatile, stable, and optically addressable platform for investigating topological order and strong correlations in two-dimensional landscapes.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
Reconstructions and Dynamics of $β$-Lithium Thiophosphate Surfaces
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Hanna Türk, Davide Tisi, Michele Ceriotti
Lithium thiophosphate (LPS) is a promising solid electrolyte for next-generation lithium-ion batteries due to its superior energy storage, high ionic conductivity, and low-flammability components. Despite its potential, the high reactivity of LPS with common contaminants such as atmospheric water, preparation solvents, and electrode materials poses significant challenges for commercialization. The lack of understanding regarding the structure, morphology, and chemical behavior of LPS’s surface slows down the search for solutions to these issues. Here, we utilize a machine learning interatomic potential to achieve a fundamental, atomistic understanding of the mechanical and chemical properties of the $ \beta$ -Li$ _3$ PS$ _4$ surfaces. Employing molecular dynamics simulations, we identify relevant surface complexions formed by surface reconstructions, determine their surface energies and compute the Wulff shape of $ \beta$ -LPS. The most stable complexions exhibit properties distinctly different from the bulk, including amorphization, increased density, decreased conductivity and large deformation of the structure building blocks. We demonstrate that these surfaces are not static, but undergo significant dynamical activity which is clearly identified by an analysis featuring a time-averaged structural descriptor. Finally, we examine the changes of the electronic structure induced by the surface complexions, which provides us with details on changes in surface reactivity and active sites, underlining the importance to investigate surface complexions under realistic conditions.
Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn)
Dynamical electronic correlation and chiral magnetism in van der Waals magnet Fe4GeTe2
New Submission | Other Condensed Matter (cond-mat.other) | 2025-04-17 20:00 EDT
Md. Nur Hasan, Nastaran Salehi, Felix Sorgenfrei, Anna Delin, Igor Di Marco, Anders Bergman, Manuel Pereiro, Patrik Thunström, Olle Eriksson, Debjani Karmakar
Among the quasi-2D van der Waals magnetic systems, Fe4GeTe2 imprints a profound impact due to its near-room temperature ferromagnetic behaviour and the complex magnetothermal phase diagram exhibiting multiple phase transformations, as observed from magnetization and magnetotransport measurements. A complete analysis of these phase transformations in the light of electronic correlation and its impact on the underlying magnetic interactions remain unattended in the existing literature. Using first-principles methodologies, incorporating the dynamical nature of electron correlation, we have analysed the interplay of the direction of magnetization in the easy-plane and easy-axis manner with the underlying crystal symmetry, which reveals the opening of a pseudogap feature beyond the spin-reorientation transition (SRT) temperature. The impact of dynamical correlation on the calculated magnetic circular dichroism and x-ray absorption spectrum of the L-edge of the Fe atoms compared well with the existing experimental observations. The calculated intersite Heisenberg exchange interactions display a complicated nature, depending upon the pairwise interactions among the two inequivalent Fe sites, indicating a RKKY-like behaviour of the magnetic interactions. We noted the existence of significant anisotropic and antisymmetric exchanges interactions, resulting into a chirality in the magnetic behaviour of the system. Subsequent investigation of the dynamical aspects of magnetism in Fe4GeTe2 and the respective magnetothermal phase diagram reveal that the dynamical nature of spins and the decoupling of the magnetic properties for both sites of Fe is crucial to explain all the experimentally observed phase transformations.
Other Condensed Matter (cond-mat.other), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el), Computational Physics (physics.comp-ph), Quantum Physics (quant-ph)
Accepted for publication as a Regular Article in Physical Review B
X-ray scattering investigation of hydride surface segregation in epitaxial Nb films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
David A. Garcia-Wetten, Philip J. Ryan, Jong Woo Kim, Dominic P Goronzy, Roger J. Reinertsen, Mark C. Hersam, Michael J. Bedzyk
Hydride precipitation in niobium-based, superconducting circuits is a damaging side-effect of hydrofluoric acid treatments used to clean and thin the Nb surface oxides and Si oxides. The precipitate microstructure is difficult to probe because of the high hydrogen mobility in the niobium matrix. In particular, destructive techniques used to prepare samples for elemental depth profiling can change the hydride structure. Here, we use X-ray surface scattering to non-destructively probe the depth distribution of precipitates in hydrided, epitaxial, niobium thin films. We find that the niobium hydride is confined within the top ten nm of the surface.
Materials Science (cond-mat.mtrl-sci)
11 pages, 5 figures
A statistical understanding of oxygen vacancies in distorted high-entropy oxides
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Adam Potter, Yifan Wang, Dongjae Kong, Yuzhe Li, Jian Qin, Xiaolin Zheng
High entropy perovskite oxides (HEPOs) have emerged as a promising family of stable electrode materials for high-temperature water splitting. The concentration of oxygen vacancies in HEPOs significantly influences critical properties, such as the ionic conductivity and thermal expansion coefficient. However, predicting their concentration in HEPOs remains a challenge due to the complex and high-entropic arrangements of metal cations. Here, we employ a combined experimental, computational, and theoretical approach to quantify the oxygen vacancy concentration and understand its dependence on the A-site cation compositions of HEPOs. While we found that the concentration of the A-site 2+ cation influences the oxygen vacancy concentration, as expected, this factor alone is insufficient. Our findings reveal that variations in A-site cation size constitute another crucial factor in affecting the oxygen vacancy concentration. We investigated this dependence through atomistic simulations using a machine-learned universal interatomic potential, demonstrating that the lattice distortions from A-site size variations result in a broadened distribution of oxygen vacancy formation energies. Our theoretical analysis, grounded in statistical thermodynamics, further provides formulations for the enthalpy and entropy of oxygen vacancy formation as functions of variance in oxygen bonding energy. Overall, our experimental, computational, and theoretical findings consistently highlight the significant impact of A-site cation site variations on the oxygen vacancy concentration in perovskites, providing a new approach to adjusting the oxygen vacancy concentrations in these materials.
Materials Science (cond-mat.mtrl-sci)
On the microplasticity and dynamic strain aging in an FeAlCrMo complex-concentrated alloy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Tomáš Tayari, Michal Knapek, Eliška Jača, Peter Minárik, Josef Pešička
We show by acoustic emission analysis that FeAlCrMo complex-concentrated alloy (CCA) exhibits signatures of self-organization of deformation processes during both microplasticity and serrated flow (dynamic strain aging). Due to complex microstructures of CCAs and scarcity of literature data, these novel alloys are a prominent subject of future research efforts.
Materials Science (cond-mat.mtrl-sci)
Preprint article; contains 12 pages, 4 figures
Relation of Continuous Chirality Measure to Spin and Orbital Polarization, and Chiroptical Properties in Solids
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Andrew Grieder, Shihao Tu, Yuan Ping
Chirality introduces intriguing topological, electronic, and optical properties to molecules and solids. In this work, we investigate the influence of structural chirality on spin and orbital polarization as well as optical activity through first-principles calculations and continuous chirality measure (CCM). By using chiral selenium (Se) and 2D hybrid perovskites as examples, we demonstrate that chirality continuously modifies spin-orbit splitting and orbital angular momentum (OAM) polarization. We establish a direct relation between chirality transfer across organic-inorganic interfaces and inversion symmetry breaking, which induces Rashba-Dresselhaus spin splitting in hybrid perovskites. Additionally, we examine the effects of chirality on circular dichroism (CD) and the circular photogalvanic effect (CPGE), demonstrating how the continuous tuning of chirality dictates their magnitude and anisotropy. Our findings highlight that applying hydrostatic pressure can effectively tune the CCM, thereby enhancing the chirality-induced effects such as spin selectivity. By integrating CCM with electronic structure calculations, we present a predictive strategy for designing chiral materials with tailored optical and spintronic functionalities.
Materials Science (cond-mat.mtrl-sci)
Identifying high performance spectrally-stable quantum defects in diamond
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Yihuang Xiong, Yizhi Zhu, Shay McBride, Sinéad M. Griffin, Geoffroy Hautier
Point defects in semiconductors are becoming central to quantum technologies. They can be used as spin qubits interfacing with photons, which are fundamental for building quantum networks. Currently, the most prominent quantum defect in diamond is the nitrogen-vacancy (NV) center. However, it suffers from spectral diffusion that negatively impacts optical coherence and is due to the coupling of the emission energy with uncontrolled electric fields. The group IV vacancy complexes on the other hand have shown to be significantly more spectrally-stable as they are centrosymmetric and thus immune to the linear Stark shift. They however suffer from several issues ranging from low operation temperature to low optical efficiency due to dark states and difficulty in stabilizing the right defect charge state. Here we search for alternative to the group IV vacancy complex in diamond by systematically evaluating all possible vacancy complex using high-throughput first-principles computational screening. We identify the defects that combine centrosymmetry, emission in the visible range, as well as favorable and achievable electronic structure promoting higher operation temperature and defect levels well within the band gap. We find Zn$ V^{-2}$ to be especially appealing.
Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
Practical considerations for crystallographic and microstructure mapping with direct electron detector-based electron backscatter diffraction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Tianbi Zhang, Ruth Birch, Graeme Francolini, Ebru Karakurt Uluscu, Ben Britton
Compact direct electron detectors are becoming increasingly popular in electron microscopy applications including electron backscatter diffraction, as they offer an opportunity for low cost and accessible microstructural analysis. In this work, we explore how one of these commercial devices based on the Timepix chip can be optimized to obtain high quality data quickly and easily, through careful systematic analysis of a variety of samples, including: semiconductor silicon, commercially pure nickel, a dual phase titanium-molybdenum alloy, and a silicon carbide ceramic matrix composite. Our findings provide strategies for very fast collection of orientation maps, including at low voltage (5-10 keV) and low beam current conditions. Additionally, strategies for collection of very high quality EBSD patterns are demonstrated that have significant potential for advanced EBSD applications (e.g. elastic strain mapping).
Materials Science (cond-mat.mtrl-sci)
as submitted
Uncertainty Quantification in Multiscale Modeling of Polymer Composite Materials Using Physically Recurrent Neural Networks
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-17 20:00 EDT
N. Kovács (1, 2), I.B.C.M. Rocha (2), F.P. van der Meer (2), C. Furtado (1), P.P. Camanho (1) ((1) INEGI, Faculdade de Engenharia, Universidade do Porto, (2) Delft University of Technology, Department of Civil Engineering and Geosciences)
This study investigates whether Physically Recurrent Neural Networks (PRNNs), a recent surrogate model for heterogeneous materials, trained on a micromodel with fixed material parameters, can maintain accuracy for varying material properties without retraining, and propagate uncertainty in a multiscale framework. Unlike conventional RNNs, where parameter changes require training or explicit inclusion of material properties as extra input features, PRNNs embeds material models in their material layer that allow for modification of material parameters after training. When adjusting material properties dynamically according to the input during testing, PRNN shows high accuracy across a wide range of parameters. Therefore the surrogate can be applied to multiscale uncertainty quantification (UQ). Compared to the full-order simulations on an overly coarse mesh, the PRNN-driven model reduces simulation time by over 7000 times while accurately capturing highly nonlinear evolution of the probability density for the macroscopic response as a result of a given distribution for microscale material parameters. A PRNN-driven UQ is demonstrated on a more accurate finer mesh that would be computationally infeasible with the full-order model.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Materials Science (cond-mat.mtrl-sci), Numerical Analysis (math.NA)
Magnetoresistivity in the Antiferromagnetic Hubbard Model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
Joel Bobadilla, Marcelo J. Rozenberg, Alberto Camjayi
We investigate the magnetotransport properties of the half-filled antiferromagnetic (AF) one-band Hubbard model under an external magnetic field using the single-site dynamical mean-field approximation (DMFT). Particular attention is paid to the mechanisms driving the magnetoresistivity behavior. We analyze the dependence of magnetoresistivity on temperature and the strength of the applied magnetic field, providing insights into the interplay between magnetic fluctuations and transport properties in AF systems.
Strongly Correlated Electrons (cond-mat.str-el)
Towards High-Voltage Cathodes for Zinc-Ion Batteries: Discovery Pipeline and Material Design Rules
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Roberta Pascazio (1 and 2), Qian Chen (1,2 and 3), Haoming Howard Li (1 and 2), Aaron D. Kaplan (2), Kristin A. Persson (1 and 2) ((1) University of California, Berkeley, (2) Lawrence Berkeley National Laboratory (3), Toyota Research Institute of North America)
Efficient energy storage systems are crucial to address the intermittency of renewable energy sources. As multivalent batteries, Zn-ion batteries (ZIBs), while inherently low voltage, offer a promising low cost alternative to Li-ion batteries due to viable use of zinc as the anode. However, to maximize the potential impact of ZIBs, rechargable cathodes with improved Zn diffusion are needed. To better understand the chemical and structural factors influencing Zn-ion mobility within battery electrode materials, we employ a high-throughput computational screening approach to systematically evaluate candidate intercalation hosts for ZIB cathodes, expanding the chemical search space on empty intercalation hosts that do not contain Zn. We leverage a high-throughput screening funnel to identify promising cathodes in ZIBs, integrating screening criteria with DFT-based calculations of Zn$ ^{2+}$ intercalation and diffusion inside the host materials. Using this data, we identify the design principles that favor Zn-ion mobility in candidate cathode materials. Building on previous work on divalent ion cathodes, this study broadens the chemical space for next-generation multivalent energy storage systems.
Materials Science (cond-mat.mtrl-sci)
Predominant Electronic Order Parameter for Structural Chirality – Role of Spinless Electronic Toroidal Multipoles
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
We discuss predominant order parameters for structural chirality, and demonstrate that time-reversal-even axial-quadrupole plays a key role in stabilizing a chiral structure. Using the symmetry-adapted closest Wannier model of the trigonal Te and Se, we quantify the evolution of the spin-independent (spinless) and spin-dependent (spinful) electric toroidal (ET) (axial) multipole moments across the transition from an achiral to a chiral structure. Our results clearly identify that a spin-independent off-diagonal real hopping between $ p$ orbitals, which corresponds to the bond-cluster spinless ET quadrupole of $ (3z^{2}-r^{2})$ type $ G_{u}$ , is the predominant order parameter in stabilizing helical structures. We further elucidate that the above itinerant spinless ET quadrupole induces a monopole-like orbital angular momentum texture in the momentum space, which can be observed via circular-dichroism in soft x-ray photoemission spectroscopy measurement. Our findings highlight a critical role of the orbital angular momentum in chiral materials rather than less dominant spin angular momentum arising from the relativistic spin-orbit coupling.
Materials Science (cond-mat.mtrl-sci)
Velocity Distribution and Diffusion of an Athermal Inertial Run-and-Tumble Particle in a Shear-Thinning Medium
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-17 20:00 EDT
Sayantan Mondal, Prasenjit Das
We study the dynamics of an athermal inertial active particle moving in a shear-thinning medium in $ d=1$ . The viscosity of the medium is modeled using a Coulomb-tanh function, while the activity is represented by an asymmetric dichotomous noise with strengths $ -\Delta$ and $ \mu\Delta$ , transitioning between these states at a rate $ \lambda$ . Starting from the Fokker-Planck(FP) equation for the time-dependent probability distributions $ P(v,-\Delta,t)$ and $ P(v,\mu\Delta,t)$ of the particle’s velocity $ v$ at time $ t$ , moving under the influence of active forces $ -\Delta$ and $ \mu\Delta$ respectively, we analytically derive the steady-state velocity distribution function $ P_s(v)$ , explicitly dependent on $ \mu$ . Also, we obtain a quadrature expression for the effective diffusion coefficient $ D_e$ for the symmetric active force case($ \mu=1$ ). For a given $ \Delta$ and $ \mu$ , we show that $ P_s(v)$ exhibits multiple transitions as $ \lambda$ is varied. Subsequently, we numerically compute $ P_s(v)$ , the mean-squared velocity $ \langle v^2\rangle(t)$ , and the diffusion coefficient $ D_e$ by solving the particle’s equation of motion, all of which show excellent agreement with the analytical results in the steady-state. Finally, we examine the universal nature of the transitions in $ P_s(v)$ by considering an alternative functional form of medium’s viscosity that also capture the shear-thinning behavior.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
20 Pages, 7 Figures, Accepted to Physics of Fluids
Epitaxial formation of ultrathin HfO2 on graphene by sequential oxidation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Zhenjing Liu, Qian Mao, Varun Kamboj, Rishabh Kothari, Paul Miller, Kate Reidy, Adri C. T. van Duin, R. Jaramillo, Frances M. Ross
We demonstrate the formation of epitaxial, ultrathin hafnia (HfO2) on graphene. Monoclinic hafnia (m-HfO2) forms as the end of a series of sequential oxidation reactions. Starting from Hf metal grown epitaxially on graphene, oxidation leads first to an amorphous suboxide (a-HfOx), then to a crystalline, hexagonal suboxide (h-HfOx) in epitaxial relationship with the substrate, and finally to m-HfO2 that is also epitaxial. We use scanning transmission electron microscopy to characterize the epitaxial relationships and to investigate the structure of h-HfOx. We propose a series of displacive transformations that relate the different crystalline phases and are consistent with the observed epitaxial relationships with the graphene substrate. ReaxFF based reactive molecular dynamics simulations confirm our model of the oxide phase sequencing, and illustrate the role of graphene in promoting oxide crystallization. Our results suggest a way to achieve heteroepitaxial integration of high-performance, crystalline dielectrics with two dimensional (2D) semiconductors with an atomically sharp interface, which is also relevant to hafnia phase engineering.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Ideal antiferroelectricity with large digital electrostrain in PbZrO3 epitaxial thin films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Yangyang Si, Ningbo Fan, Yongqi Dong, Zhen Ye, Shiqing Deng, Yijie Li, Chao Zhou, Qibin Zeng, Lu You, Yimei Zhu, Zhenlin Luo, Sujit Das, Laurent Bellaiche, Bin Xu, Huajun Liu, Zuhuang Chen
Antiferroelectrics exhibit reversible antipolar-polar phase transitions under electric fields, yielding large electrostrain suitable for electromechanical devices. Nevertheless, in thin-film form, the antiferroelectric behavior is often obscured by competing ferroic orders, resulting in slanted hysteresis loops with undesired remnant polarization, subsequently posing challenges in obtaining ideal antiferroelectricity and understanding their intrinsic electrical behavior. Here, atomistic models for controllable antiferroelectric-ferroelectric phase transition pathways are unveiled along specific crystallographic directions. Guided by the anisotropic phase transition and orientation design, we achieved ideal antiferroelectricity with square double hysteresis loop, large saturated polarization (60 {\mu}C/cm2), near-zero remnant polarization, fast response time (75 ns), and near-fatigue-free performance (10^10 cycles) in (111)P-oriented PbZrO3 epitaxial thin films. Moreover, a bipolar and frequency-independent digital electrostrain (0.83%) were demonstrated in this architype antiferroelectric system. In-situ X-ray diffraction studies further reveal that the large digital electrostrain results from intrinsic field-induced antiferroelectric-ferroelectric structural transition. This work demonstrates the anisotropic phase transition mechanism and ideal antiferroelectricity with large digital electrostrain in antiferroelectric thin films, offering a new avenue for applications of antiferroelectricity in nanoelectromechanical systems.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
22pages, 5 figures
Spectroscopic evidence for possible quantum spin liquid behavior in a two-dimensional Mott insulator
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
Haiyang Chen, Fo-Hong Wang, Qiang Gao, Xue-Jian Gao, Zhenhua Chen, Yaobo Huang, Kam Tuen Law, Xiao Yan Xu, Peng Chen
Mott insulators with localized magnetic moments will exhibit a quantum spin liquid (QSL) state when the quantum fluctuations are strong enough to suppress the ordering of the spins. Such an entangled state will give rise to collective excitations, in which spin and charge information are carried separately. Our angle-resolved photoemission spectroscopy (ARPES) measurements on single-layer 1T-TaS2 show a flat band around the zone center and a gap opening of about 200 meV in the low temperature, indicating 2D Mott insulating nature in the system. This flat band is dispersionless in momentum space but shows anomalously broad width around the zone center and the spectral weight decays rapidly as momentum increases. The observation is described as a spectral continuum from electron fractionalization, corroborated by a low energy effective this http URL intensity of the flat band is reduced by surface doping with magnetic adatoms and the gap is closing, a result from the interaction between spin impurities coupled with spinons and the chargons, which gives rise to a charge redistribution. Doping with nonmagnetic impurities behaves differently as the chemical potential shift dominates. These findings provide insight into the QSL states of strongly correlated electrons on 2D triangular lattices.
Strongly Correlated Electrons (cond-mat.str-el)
Phys. Rev. Lett. 134, 066402 (2025)
Efficient spin-orbit torque driven magnetization switching of GdFe using phosphorus-implanted platinum layers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Kazuki Shintaku, Arun Jacob Mathew, Akihisa Iwamoto, Mojtaba Mohammadi, Hiroyuki Awano, Hironori Asada, Yasuhiro Fukuma
The capability of the spin-orbit torque (SOT) generated via phenomena such as the spin Hall effect in heavy metals, in switching the magnetization of an adjacent magnetic material, has been studied extensively over the last decade. The efficiency of SOT generation is commonly quantified in terms of the spin Hall angle {\theta}_SH. In this work, we demonstrate experimentally that implanting platinum (Pt) with phosphorus (P), resulting in Pt (P) d, where d denotes the implantation dose, increases {\theta}_SH by a factor of 7, from 0.06 (d = 0) to 0.43 (d = 10\ast10^16 ions/cm^2). The enhanced {\theta}_SH, along with factors such as perpendicular magnetic anisotropy and resistivity, lead to reduction of the critical current density for switching the perpendicular magnetization of ferrimagnetic rare earth-transition metal alloy Gd26Fe74, by a factor of nearly 27, from 4.0\ast1011 A/m^2 (d = 0) to 1.5\ast10^10 A/m^2 (d = 10\ast10^16 ions/cm^2). Further, the switching current density at zero thermal fluctuations and thermal stability factor were evaluated and found to be 2.0\ast10^10 A/m^2 and 61.4 (d = 10\ast10^16 ions/cm^2), with the latter being sufficiently above the required threshold for commercial memory applications. Our results suggest that Pt (P) could be a strong candidate in realizing efficient SOT driven magnetization switching leading to the development of improved memory and logic devices in the future.
Materials Science (cond-mat.mtrl-sci)
Phase Separation in Active Binary Mixtures With Chemical Reaction
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-17 20:00 EDT
Sayantan Mondal, Prasenjit Das
We study motility-induced phase separation~(MIPS) in active AB binary mixtures undergoing the chemical reaction $ A \rightleftharpoons B$ . Starting from the evolution equations for the density fields $ \rho_i(\vec r, t)$ describing MIPS, we phenomenologically incorporate the effects of the reaction through the reaction rate $ \Gamma$ into the equations. The steady-state domain morphologies depend on $ \Gamma$ and the relative activity of the species, $ \Delta$ . For a sufficiently large $ \Gamma$ and $ \Delta\ne 1$ , the more active component of the mixture forms a droplet morphology. We characterize the morphology of domains by calculating the equal-time correlation function $ C(r, t)$ and the structure factor $ S(k, t)$ , exhibiting scaling violation. The average domain size, $ L(t)$ , follows a diffusive growth as $ L(t)\sim t^{1/3}$ before reaching the steady state domain size, $ L_{\rm ss}$ . Additionally, $ L_{\rm ss}$ shows the scaling relation $ L_{\rm ss}\sim\Gamma^{-1/4}$ , independent of $ \Delta$ .
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
16 Pages, 7 Figures, Accepted to Soft Matter
Density-field structures in a few systems undergoing velocity ordering
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-17 20:00 EDT
Subir K. Das, Sohini Chatterjee, Wasim Akram, Subhajit Paul, Saikat Chakraborty, Arabinda Bera
We consider two (off-lattice) varieties of out-of-equilibrium systems, viz., granular and active matter systems, that, in addition to displaying velocity ordering, exhibit fascinating pattern formation in the density field, similar to those during vapor-liquid phase transitions. In the granular system, velocity ordering occurs due to reduction in the normal components of velocities, arising from inelastic collisions. In the active matter case, on the other hand, velocity alignment occurs because of the inherent tendency of the active particles to follow each other. Inspite of this difference, the patterns, even during density-field evolutions, in these systems can be remarkably similar. This we have quantified via the calculations of the two-point equal time correlation functions and the structure factors. These results have been compared with the well studied case of kinetics of phase separation within the framework of the Ising model. Despite the order-parameter conservation constraint in all the cases, in the density field, the quantitative structural features in the Ising case is quite different from those for the granular and active matters. Interestingly, the correlation function for the latter varieties, particularly for an active matter model, quite accurately describes the structure in a real assembly of biologically active particles.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Thermodynamic Uncertainty Relation for $f$-divergence Entropy Production
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-17 20:00 EDT
We propose an $ f$ -divergence extension of the Hasegawa-Nishiyama thermodynamic uncertainty relation. More precisely, we introduce the stochastic thermodynamic entropy production based on generalised $ f$ -divergences and derive corresponding uncertainty relations in connection with the symmetry entropy.
Statistical Mechanics (cond-mat.stat-mech)
Stability of Highly Hydrogenated Monolayer Graphene in Ultra-High Vacuum and in Air
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Alice Apponi (1,2), Orlando Castellano (1,2), Daniele Paoloni (1,2), Domenica Convertino (3), Neeraj Mishra (3), Camilla Coletti (3,4), Andrea Casale (5), Luca Cecchini (8), Alfredo G. Cocco (6), Benedetta Corcione (7,8), Nicola D’Ambrosio (6), Angelo Esposito (7,8), Marcello Messina (6), Francesco Pandolfi (8), Francesca Pofi (6,9), Ilaria Rago (8), Nicola Rossi (6), Sammar Tayyab (7,8), Ravi Prakash Yadav (7,8), Federico Virzi (6,10), Carlo Mariani (7,8), Gianluca Cavoto (7,8), Alessandro Ruocco (1,2) ((1) Dipartimento di Scienze, Università degli Studi di Roma Tre, (2) INFN Sezione di Roma Tre, (3) Center for Nanotechnology Innovation @NEST, (4) Graphene Labs, Istituto italiano di tecnologia, (5) Department of Physics, Columbia University, (6) INFN-LNGS, (7) Sapienza Università di Roma, (8) INFN Sezione di Roma, (9) Gran Sasso Science Institute, (10) Università degli Studi dell’Aquila)
The stability of hydrogenated monolayer graphene was investigated via X-ray photoemission spectroscopy (XPS) for two different environmental conditions: ultra-high vacuum (UHV) and ambient pressure. The study is carried out by measuring the C 1s line shape evolution for two hydrogenated samples one kept in the UHV chamber and the other progressively exposed to air. In particular, the $ sp^3$ relative intensity in the C 1s core-level spectrum, represented by the area ratio $ \frac{sp^3}{sp^2+sp^3}$ , was used as a marker for the hydrogenation-level and it resulted to vary by (4 $ \pm$ 2)$ %$ in UHV after four months. Thus, a long-term stability of hydrogenated monolayer graphene was found, that indicates this material as a good candidate for hydrogen (or tritium) storage as long as it is kept in vacuum. On the other hand, the C 1s spectrum of the sample exposed to air shows a significant oxidation. A rapid growth up to saturation of the carbon oxides was observed with a time constant $ \tau$ = 1.8 $ \pm$ 0.2 hours. Finally, the re-exposure of the oxidised sample to atomic hydrogen was found to be an effective method for the recovery of hydrogenated graphene. This process was studied by carrying out both XPS and electron energy loss spectroscopy, the latter exploited to observe the CH stretching mode as a direct footprint of re-hydrogenation.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Visualization Analysis and Impedance Analysis for the Aging Behavior Assessment of 18650 Cells
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Yihan Shi, Qingrui Pan, Jitao Li, Xiaoze Shi, Youchang Wang, Peng Xiao
This work presents a comprehensive study on the aging behavior of 18650-type lithium-ion batteries, focusing on the uneven intercalation of lithium ions during fast charging processes. It introduces a novel approach using color visual recognition technology to analyze color changes in the graphite anode, indicative of lithiation levels. The study employs X-ray diffraction (XRD) and Distribution of Relaxation Time (DRT) techniques to validate and analyze the observations. The study emphasizes the significance of electrode impedance, the positioning of battery tabs, and electrolyte distribution in influencing the aging dynamics of lithium-ion batteries. Furthermore, the paper presents an innovative impedance Transport-Line Model, specifically developed to capture the evolution of polarization impedance over time. This model offers a deeper understanding of the internal mechanisms driving battery aging, providing valuable insights for the design and optimization of lithium-ion batteries. The research represents a significant contribution to the field, shedding light on the complex aging processes in lithium-ion batteries, particularly under the conditions of fast charging. This could lead to improved battery performance, longevity, and safety, which are critical for the wide range of applications that depend on these energy storage systems.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Twist Grain Boundary phases in proper ferroelectric liquid crystals realm
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-17 20:00 EDT
Damian Pociecha, Jadwiga Szydlowska, Katarzyna Kwiatkowska, Marijus Juodka, Julian Spiess, John MD Storey, Corrie T Imrie, Rebecca Walker, Ewa Gorecka
The twist-grain-boundary (TGB) phases, characterized by a periodic, helical arrangement of blocks made of polar smectic phases, SmAF and SmCF, have been discovered. They have been observed for rod-like molecules with a strong longitudinal dipole moment, featuring an (S)-2-methylbutyl end group having only weak twisting power, and emerge below the antiferroelectric SmAAF phase, where the lamellar structure is already well established. It is suggested that the structure is governed by electrostatic interactions amplified by weak chiral forces, in striking contrast to the mechanism of TGB phase formation found in non-polar materials. The TGB phases exhibit light selective reflection in the visible range, while the value of electric polarization confirms an almost perfectly ordered dipole alignment.
Soft Condensed Matter (cond-mat.soft)
Understanding the evolution of the magnetic ground state in Ba$_4$NaRu$3$O${12}$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
Shruti Chakravarty, Pascal Manuel, Antonio Cervellino, Sunil Nair
We report a comprehensive investigation of the quadruple perovskite Ba$ _4$ NaRu$ _3$ O$ _{12}$ , in which we discover a robust spin-lattice coupled ground state characterized by a long-range antiferromagnetic ordering at $ T_N \sim$ 257 K. The system’s unique structural motif of three symmetrically distinct magnetic ions, including Ru dimers separated by non-magnetic layers, is intimately correlated with its magnetic behavior, as evidenced by temperature-dependent diffraction measurements and specific heat data. The powder neutron diffraction patterns at 13 K showed that the spins within the dimers are antiparallel, leading to a net zero moment contribution and a staggered arrangement of the triangular layers formed by the Ru moments within the corner-shared octahedra along the $ c$ -axis. The low-temperature specific heat revealed an extra boson peak contribution from optical modes with a maximum vibrational energy of $ \sim$ 55cm$ ^{-1}$ . The charge transport exhibited variable-range hopping (VRH) behaviour below $ T_N$ , with a stronger energy-dependence than expected from the Efros-Shklovskii model, suggesting the presence of multiparticle correlation effects.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Quantum Optical Spanner: Twisting Superconductors with Vortex Beam via Higgs Mode
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
Daemo Kang, Sota Kitamura, Takahiro Morimoto
Light carrying orbital angular momentum (OAM)–known as vortex beams–has broadened the scope of understanding and applications of light’s angular momentum. Optical tweezers using OAM, often referred to as optical spanners, have significantly expanded the tunability of optical manipulation. A key frontier now lies in understanding how vortex beams interact with quantum states of matter. In this work, we numerically investigate the dynamics of a superconductor under vortex beam illumination and demonstrate the transfer of angular momentum from light to the superconducting collective mode, resulting in mechanical rotation. Our findings open a pathway for optical manipulation in the quantum regime, which we term the quantum optical spanner.
Strongly Correlated Electrons (cond-mat.str-el), Optics (physics.optics)
5 pages, 4 figures
Training and synchronizing oscillator networks with Equilibrium Propagation
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-17 20:00 EDT
Théophile Rageau, Julie Grollier
Oscillator networks represent a promising technology for unconventional computing and artificial intelligence. Thus far, these systems have primarily been demonstrated in small-scale implementations, such as Ising Machines for solving combinatorial problems and associative memories for image recognition, typically trained without state-of-the-art gradient-based algorithms. Scaling up oscillator-based systems requires advanced gradient-based training methods that also ensure robustness against frequency dispersion between individual oscillators. Here, we demonstrate through simulations that the Equilibrium Propagation algorithm enables effective gradient-based training of oscillator networks, facilitating synchronization even when initial oscillator frequencies are significantly dispersed. We specifically investigate two oscillator models: purely phase-coupled oscillators and oscillators coupled via both amplitude and phase interactions. Our results show that these oscillator networks can scale successfully to standard image recognition benchmarks, such as achieving nearly 98% test accuracy on the MNIST dataset, despite noise introduced by imperfect synchronization. This work thus paves the way for practical hardware implementations of large-scale oscillator networks, such as those based on spintronic devices.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Emerging Technologies (cs.ET)
16 pages text with 4 figures and 16 pages of Appendix with 6 figures
Dirac Representation for Lattice Spin Operators: Spin-$1/2$ and Spin-$1$ cases
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-17 20:00 EDT
A novel quantum representation of lattice spin operators (LSOs) is achieved by mapping quantum spins onto their classical analogues for spin size $ S=1/2$ and $ S=1$ . The “braket” representations of LSOs are attained thanks to a profound inspection into the binary/ternary distribution of classical bits/trits in non-negative integers. We claim the possility of getting the $ j$ th digit of a positive integer without performing any binary/ternary decomposition. Analytical formulas returning the $ j$ th bits/trits of an integer are presented. Impacts of our achievements in Physics are highlighted by revisiting the $ 1D$ spin-$ 1/2$ {XXZ} Heisenberg model with open boundaries in a magnetic field in both absence (uniform magnetic field) and presence of disorder (random magnetic field). In the absence of disorder (clean system), we demonstrate that the corresponding eigenvalues problem can be reduced to a tight-binding problem on a graph and solved without resorting to any spinless transformation nor the Bethe Anzath. In the presence of disorder, a convergent perturbation theory is elaborated. Our analytical results are compared with data from exact diagonalization for relatively large spin systems ($ K\leq 18$ spins with $ K$ denoting the total number of spins) obtained by implementing both the global $ U(1)$ symmetry to block-diagonalize the Hamiltonian and the spin-inversion symmetry for two-fold block-diagonalization in the sector with total magnetization $ \mathcal{J}^z=0$ . We observe a good agreement between both results.
Soft Condensed Matter (cond-mat.soft)
Dissecting coupled orders in a terahertz-driven electron-doped cuprate
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-17 20:00 EDT
Liwen Feng, Haotian Zhang, Tim Priessnitz, Jiayuan Cao, Tarapada Sarkar, Thales de Oliveira, Alexey N. Ponomaryov, Igor Ilyakov, Fei Yang, Yongbo Lv, Yuheng Guo, Kilian Srowik, Steffen Danzenbacher, Moritz Niethammer, Sergey Kovalev, Jan-Christoph Deinert, Stefan Kaiser, Richard L. Greene, Hao Chu
The interplay between superconductivity and charge density wave has often been studied from an equilibrium point of view. For example, using static tuning knobs such as doping, magnetic field and pressure, superconductivity can be enhanced or suppressed. The resulting effect on the co-existing charge density wave order, if any, is judged by variations in its ground state properties such as the ordering temperature or the spatial correlation. Such an approach can be understood as coordinated static displacements of two coupled order parameters within a Ginzburg-Landau description, evincing their interplay as either co-operative or competing but does not provide further microscopic information about the interaction. In order to assess such information, we dynamically perturb both orders from equilibrium and observe their coupling directly in the time-domain. We show that high-field multicycle terahertz pulses drive both the Higgs amplitude fluctuations of the superconducting order as well as collective fluctuations of the charge order in an electron-doped cuprate, resulting in characteristic third harmonic generation. A notable time delay is manifested between their respective driven dynamics. We propose that this may signify the important energy scale describing their coupling or imply a terahertz field-depinned charge density wave that destroys macroscopic superconductivity. Our work demonstrates a holistic approach for investigating coupled superconducting and charge density wave orders, which may shed novel light on their intertwined presence and widespread fluctuations in many classes of unconventional superconductors.
Superconductivity (cond-mat.supr-con)
Introduction to Langevin Stochastic Processes
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-17 20:00 EDT
These lecture notes provide an introduction to Langevin processes and briefly discuss some interesting properties and simple applications. They compile material presented at the “School of Physics and Mathematics Without Frontiers” (ZigZag), held at La Havana, Cuba, in March 2024, the School “Information, Noise and Physics of Life” held at Niš, Serbia, in June 2024, both sponsored by ICTP, the PEBBLE summer camp at Westlake University, China, in August 2024, the Barcelona school on “Non-equilibrium Statistical Physics”, in April 2025, and the 2012-2016 course “Out of Equilibrium Dynamics of Complex Systems” for the Master 2 program “Physics of Complex Systems” in the Paris area.
Statistical Mechanics (cond-mat.stat-mech)
Lecture Notes
Unified Multipole Bott Indices for Non-Hermitian Skin Effect in Different Orders
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Non-Hermitian systems exhibit a distinctive phenomenon known as the non-Hermitian skin effect, where an extensive number of eigenstates become localized at the boundaries of a lattice with open boundaries. While the spectral winding number under periodic boundary conditions is a well-established topological indicator for predicting the skin effect in one-dimensional non-Hermitian systems, a suitable topological invariant to diagnose higher-order skin effects remains elusive. In this Letter, we propose a unified non-Hermitian multipole characterization framework that generalizes the concept of spectral winding to higher-order skin effects. Specifically, we develop a set of non-Hermitian multipole Bott indices capable of diagnosing skin effects of different orders. Our approach provides a comprehensive understanding of both first- and higher-order skin effects in non-Hermitian systems, offering new perspectives for exploring topological phenomena in non-Hermitian systems.
Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
published in Phys. Rev. B 111, 155121 (2025)
Phys. Rev. B 111, 155121 (2025)
Giant Exciton Transport in hBN/2D-Perovskite Heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-17 20:00 EDT
Sara Darbari, Paul Bittorf, Leon Multerer, Fatemeh Chahshouri, Parsa Darman, Pavel Ruchka, Harald Giessen, Masoud Taleb, Yaser Abdi, Nahid Talebi
Two-dimensional perovskites, such as Ruddlesden-Popper perovskites, exhibit outstanding optical properties and high exciton binding energies but are highly susceptible to degradation under photo- and electron-beam exposure. To overcome this limitation, we encapsulate the perovskites with mechanically exfoliated hexagonal boron nitride flakes, forming hexagonal boron nitride/perovskite heterostructures. Cathodoluminescence spectroscopy reveals that these heterostructures exhibit significantly reduced electron-beam-induced degradation, enhanced luminescence intensity, a narrower emission bandwidth, and an extended exciton decay time. Moreover, leveraging the scanning capability of our fiber-based cathodoluminescence spectroscopy technique, we demonstrate ultra-long-range exciton transport over distances of approximately 150 micrometers, attributed to exciton-defect coupling. This exciton-defect interaction not only enhances luminescence but also highlights the potential of hexagonal boron nitride/perovskite heterostructures as hybrid van-der-Waals systems with long-range exciton transport and slow radiative decay rates, paving the way for robust and efficient optoelectronic applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Integrating Neural Networks and Tensor Networks for Computing Free Energy
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-17 20:00 EDT
Hanyan Cao, Yijia Wang, Feng Pan, Pan Zhang
Computing free energy is a fundamental problem in statistical physics. Recently, two distinct methods have been developed and have demonstrated remarkable success: the tensor-network-based contraction method and the neural-network-based variational method. Tensor networks are accu?rate, but their application is often limited to low-dimensional systems due to the high computational complexity in high-dimensional systems. The neural network method applies to systems with general topology. However, as a variational method, it is not as accurate as tensor networks. In this work, we propose an integrated approach, tensor-network-based variational autoregressive networks (TNVAN), that leverages the strengths of both tensor networks and neural networks: combining the variational autoregressive neural network’s ability to compute an upper bound on free energy and perform unbiased sampling from the variational distribution with the tensor network’s power to accurately compute the partition function for small sub-systems, resulting in a robust method for precisely estimating free energy. To evaluate the proposed approach, we conducted numerical experiments on spin glass systems with various topologies, including two-dimensional lattices, fully connected graphs, and random graphs. Our numerical results demonstrate the superior accuracy of our method compared to existing approaches. In particular, it effectively handles systems with long-range interactions and leverages GPU efficiency without requiring singular value decomposition, indicating great potential in tackling statistical mechanics problems and simulating high-dimensional complex systems through both tensor networks and neural networks.
Statistical Mechanics (cond-mat.stat-mech)
Communications in Theoretical Physics, 2025
Periodic Potential for Point Defects in a 2D Hexagonal Colloidal Lattice
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-17 20:00 EDT
Huang Xicheng, Liu Zefei, Chen Yong-Cong, Yang Guohong, Ao Ping
We explore the statistical nature of point defects in a two-dimensional hexagonal colloidal crystal from the perspective of stochastic dynamics. Starting from the experimentally recorded trajectories of time series, the underlying drifting forces along with the diffusion matrix from thermal fluctuations are extracted. We then employ a deposition in which the deterministic terms are split into diffusive and transverse components under a stochastic potential with the lattice periodicity to uncover the dynamic landscape as well as the transverse matrix, two key structures from limited ranges of measurements. The analysis elucidates some fundamental dichotomy between mono-point and di-point defects of paired vacancies or interstitials. Having large transverse magnitude, the second class of defects are likely to break the detailed balance, Such a scenario was attributed to the root cause of lattice melting by experimental observations. The constructed potential can in turn facilitate large-scale simulation for the ongoing research.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
No equivalence between hydrodynamic and dispersive mass of the charged polaron
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-17 20:00 EDT
Krzysztof Myśliwy, Piotr Wysocki, Krzysztof Jachymski
We consider the problem of a charged impurity exerting a weak, slowly decaying force on its surroundings, treating the latter as an ideal compressible fluid. In the semiclassical approximation, the ion is described by the Newton equation coupled to the Euler equation for the medium. After linearization, we obtain a simple closed formula for the effective mass of the impurity, depending on the interaction potential, the mean medium density, and sound velocity. Thus, once the interaction and the equation of state of the fluid is known, an estimate of the hydrodynamic effective mass can be quickly provided. Going beyond the classical case, we show that replacing the Newton with Schrödinger equation can drastically change the behavior of the impurity. In particular, the scaling of the Fermi polaron effective mass with the medium density is opposite in quantum and classical scenario. Our results are relevant for experimental systems featuring low energy impurities in Fermi or Bose systems, such as ions immersed in neutral atomic gases.
Quantum Gases (cond-mat.quant-gas), Fluid Dynamics (physics.flu-dyn), Quantum Physics (quant-ph)
8 pages (two–column), 3 figures
Fluctuation induced network patterns in active matter with spatially correlated noise
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-17 20:00 EDT
Sebastian Fehlinger, Kai Cui, Arooj Sajjad, Heinz Koeppl, Benno Liebchen
Fluctuations play a central role in many fields of physics, from quantum electrodynamics to statistical mechanics. In active matter physics, most models focus on thermal fluctuations due to a surrounding solvent. An alternative but much less explored noise source can occur due to fluctuating external fields, which typically feature certain spatial correlations. In this work, we introduce a minimal model to explore the influence of spatially correlated but temporally uncorrelated noise on the collective behavior of active particles. We find that specifically in chiral active particles such fluctuations induce the formation of network patterns, which neither occur for spatially (uncorrelated) thermal noise, nor in the complete absence of fluctuations. These networks show (i) a percolated structure, (ii) local alignment of the contained particles, but no global alignment, and (iii) hardly coarsen. We perform a topological data analysis to systematically characterize the topology of the network patterns. Our work serves as a starting point to explore the role of spatially correlated fluctuations and presents a route towards noise-induced phenomena in active matter.
Soft Condensed Matter (cond-mat.soft)
Effect of pressure, doping and magnetism on electronic structure and phonon dispersion of FeSe
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Abyay Ghosh, Piotr Chudzinski, Myrta Grüning
We present a Density Functional Theory (DFT) based first-principles study on iron chalcogenides superconductor FeSe, systematically investigating pressure and doping induced modifications to its electronic, magnetic, and lattice dynamical properties. Our constrained-DFT calculations in striped antiferromagnetic and staggered dimer phase reveal a non-trivial dependence of the electronic structure on the local magnetic moment at all pressures. Sulpher (S) and tellurium (Te) doping exert opposing effects on the electronic structure, attributable to their contrasting chemical pressure effects (negative for S, positive for Te). Lattice dynamics calculations divulge distinct dependence of different phonon modes on local magnetic moment in different magnetic phases. We identify pressure and magnetic moment-dependent dynamical instability in certain magnetic phases, underscoring the intricate interplay of structural, electronic, and magnetic properties in this system. Investigation of spin-phonon coupling for different phonon modes shows the presence of strong magneto-elastic coupling in FeSe with pressure distinctly affecting prominent optical phonon modes – pure iron derived $ B_{1g}$ and pure selenium derived $ A_{1g}$ . A clear indication of the change in spin-phonon coupling with pressure is visible, especially for the $ B_{1g}$ mode.
Materials Science (cond-mat.mtrl-sci)
References are not showing in the preview
Impact of spin correlations on resistivity and microwave absorption of Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-17 20:00 EDT
Yu.I.Talanov, I.I.Gimazov, D.E.Zhelezniakova
The results of studies of BaFe$ _2$ As$ _2$ single crystals doped with cobalt by means of resistivity and microwave absorption measurement are reported. A theoretical description of the behavior of the microwave absorption amplitude is made taking into account the temperature dependence of resistivity, magnetic susceptibility and the lifetime of spin fluctuations. An assumption has been made that the deviation from the linear dependence of resistivity on temperature at $ T<100$ K is not related to the electron-electron scattering mechanism, but it is due to the appearance of nematic fluctuations. Estimates of the rate of scattering by spin fluctuations indicate their nematic nature at temperatures near the structural transition.
Superconductivity (cond-mat.supr-con)
6 pages, 3 figures
Magn. Reson. Solids 26, 24110 (2024)
Resonant x-ray scattering study of charge-density wave correlations in YBa${2}$Cu${3}$O$_{6+x}$ under uniaxial stress
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-17 20:00 EDT
S. Nakata, D. Betto, E. Schierle, S. Hameed, Y. Liu, H.-H. Kim, S. M. Souliou, T. Lacmann, K. Fürsich, T. Loew, E. Weschke, A. P. Mackenzie, C. W. Hicks, M. Le Tacon, B. Keimer, M. Minola
We report a comprehensive study of the uniaxial stress response of charge-density-wave (CDW) correlations in detwinned single crystals of the high temperature superconductor YBa$ _2$ Cu$ _3$ O$ _{6+x}$ (YBCO$ _{6+x}$ ) with $ 0.40 \leq x \leq 0.93$ (hole-doping levels $ 0.072 \leq p \leq 0.168$ ) by means of Cu $ L_3$ -edge resonant energy-integrated x-ray scattering (REXS). We show that the influence of uniaxial stress is strongly doping dependent: the quasi-two-dimensional CDW is enhanced by in-plane uniaxial stress in a wide hole doping range ($ 0.45 \leq x \leq 0.80$ ), but only barely affected in the most underdoped and optimally doped samples ($ x = 0.40$ and 0.93), where the CDW correlation length is minimal. A stress-induced three-dimensionally long-range ordered (3D) CDW was observed only in YBCO$ _{6.50}$ and YBCO$ _{6.67}$ . The temperature dependence of the 3D CDW clearly indicates a strong competition with superconductivity. Based on the systematic strain-, doping-, and temperature-dependent REXS measurements reported here, we discuss the relationship between charge order and superconductivity in YBCO$ _{6+x}$ and other cuprates.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
11 pages, 10 figures
Phys. Rev. B 111, 115152 (2025)
Vibration-assisted tunneling through single Au adatoms on two-dimensional WSe2
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-17 20:00 EDT
Hitesh Kumar, Yu-Chuan Lin, Joshua A. Robinson, Stefan Fölsch
Scanning tunneling microscopy (STM) at 5 K was used to study individual Au atoms adsorbed on the surface of a WSe2 layer grown on epitaxial graphene. In line with theoretical predictions, scanning tunneling spectroscopy measurements reveal that the weakly bound adatom gives rise to an electronic state within the energy band gap of the WSe2 layer. Adatoms in different surface locations show different gap-state energy values that follow a random distribution around the Fermi level of the sample with a standard deviation of ~50 meV. The location-dependent shift is attributed to spatial variations in disorder potential. Tunneling via the gap state is accompanied by vibrational excitations as apparent from pronounced sideband peaks in the conductance spectra with Poisson-distributed intensities indicating significant electron-phonon coupling with a Huang-Rhys factor of S=2.8. STM tunneling through single Au adatoms on two-dimensional WSe2 constitutes a model case of resonant double-barrier tunneling accompanied by strong coupling to vibrational degrees of freedom.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
17 pages, 8 figures
Pressure-tuned spin chains in brochantite, Cu$_4$SO$_4$(OH)$_6$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
Victoria A. Ginga, Bin Shen, Ece Uykur, Nico Giordano, Philipp Gegenwart, Alexander A. Tsirlin
Using high-pressure single-crystal x-ray diffraction combined with thermodynamic measurements and density-functional calculations, we uncover the microscopic magnetic model of the mineral brochantite, Cu$ _4$ SO$ _4$ (OH)$ _6$ , and its evolution upon compression. The formation of antiferromagnetic spin chains with the effective intrachain coupling of $ J\simeq 100$ ,K is attributed to the occurrence of longer Cu–Cu distances and larger Cu–O–Cu bond angles between the structural chains within the layers of the brochantite structure. These zigzag spin chains are additionally stabilized by ferromagnetic couplings $ J_2$ between second neighbors and moderately frustrated by several antiferromagnetic couplings that manifest themselves in the reduced Néel temperature of the material. Pressure tuning of the brochantite structure keeps its monoclinic symmetry unchanged and leads to the growth of antiferromagnetic $ J$ with the rate of 3.2,K/GPa, although this trend is primarily caused by the enhanced ferromagnetic couplings $ J_2$ . Our results show that the nature of magnetic couplings in brochantite and in other layered Cu$ ^{2+}$ minerals is controlled by the size of the lattice translation along their structural chains and by the extent of the layer buckling.
Strongly Correlated Electrons (cond-mat.str-el), Other Condensed Matter (cond-mat.other)
11 pages, 6 figures
Unconventional and anomalous magnetic field distribution in a bilayer superconductor with geometric constraints
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-17 20:00 EDT
We investigate the magnetic field distribution in multi-component superconductors. We examine a layered superconductor and a two-component one-layer superconductor. We evaluate the field distribution in the presence of a half-flux quantum vortex with a kink structure in the phase space of gap functions. We also examine the magnetic field distribution of a knot soliton which is formulated in a two-component superconductor. We investigate the effect of geometric constraints for multi-component superconductors, where the geometric constraint means that the system is compactified in one direction so that the current in this direction becomes vanishingly small. This corresponds to the gauge fixing in this direction. An unconventional magnetic field distribution takes place; here the unconventional means that the magnetic field is screened incompletely which would be called the anomalous Meissner effect. We argue that this anomalous behavior creates a massless gauge field.
Superconductivity (cond-mat.supr-con)
8 figures
Physics Letters A 525 (2024) 129847
Coincident onset of charge order and pseudogap in a homogeneous high-temperature superconductor
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-17 20:00 EDT
D. Betto, S. Nakata, F. Pisani, Y. Liu, S. Hameed, M. Knauft, C. Lin, R. Sant, K. Kummer, F. Yakhou, N. B. Brookes, B. Keimer, M. Minola
Understanding high-temperature superconductivity in cuprates requires knowledge of the metallic phase it evolves from, particularly the pseudogap profoundly affecting the electronic properties at low carrier densities. A key question is the influence of chemical disorder, which is ubiquitous but exceedingly difficult to model. Using resonant x-ray scattering, we identified two-dimensional charge order in stoichiometric YBa$ _2$ Cu$ _4$ O$ _8$ ($ T_c$ = 80 K), which is nearly free of chemical disorder. The charge order amplitude shows a concave temperature dependence and vanishes sharply at $ T^\ast$ = 200 K, the onset of a prominent pseudogap previously determined by spectroscopy, suggesting a causal link between these phenomena. The gradual onset of charge order in other cuprates is thus likely attributable to an inhomogeneous distribution of charge ordering temperatures due to disorder induced by chemical substitution. The relationship between the pseudogap and the disorder-induced gradual freeze-out of charge carriers remains a central issue in research on high-$ T_c$ superconductors.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
D. Betto and S. Nakata contributed equally. (21 pages, 12 figures)
Nature Communications 16, 3579 (2025)
Max-Cut graph-driven quantum circuit design for planar spin glasses
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-17 20:00 EDT
Seyed Ehsan Ghasempouri, Gerhard W. Dueck, Stijn De Baerdemacker
Finding the ground state of spin glasses is a challenging problem with broad implications. Many hard optimization problems, including NP-complete problems, can be mapped, for instance, to the Ising spin glass model. We present a graph-based approach that allows for accurate state initialization of a frustrated triangular spin-lattice with up to 20 sites that stays away from barren plateaus. To optimize circuit efficiency and trainability, we employ a clustering strategy that organizes qubits into distinct groups based on the maximum cut technique, which divides the lattice into two subsets maximally disconnected. We provide evidence that this Max-Cut-based lattice division offers a robust framework for optimizing circuit design and effectively modeling frustrated systems at polynomial cost. All simulations are performed within the variational quantum eigensolver (VQE) formalism, the current paradigm for noisy intermediate-scale quantum (NISQ), but can be extended beyond. Our results underscore the potential of hybrid quantum-classical methods in addressing complex optimization problems.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Chemical Physics (physics.chem-ph), Quantum Physics (quant-ph)
Magnetic Pair Distribution Function and Half Polarized Neutron Powder Diffraction at the HB-2A Powder Diffractometer
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
Raju Baral, Danielle R. Yahne, Malcolm J. Cochran, Matthew Powell, Joseph W. Kolis, Haidong Zhou, Stuart Calder
Local magnetic order and anisotropy are often central for understanding fundamental behavior and emergent functional properties in quantum materials and beyond. Advances in neutron powder diffraction experiments and analysis tools now allow for quantitative determination. We demonstrate this here with complementary total neutron scattering and polarized neutron measurements on the HB-2A neutron powder diffractometer at the High Flux Isotope Reactor (HFIR). In recent years, magnetic pair distribution function (mPDF) analysis has emerged as a powerful technique for probing local magnetic spin ordering of magnetic materials. This method can be broadly applied to any magnetic material but is particularly effective for studying systems with short-range magnetic order, such as materials with reduced dimensionality, geometrically frustrated magnets, thermoelectrics, multiferroics, and correlated paramagnets. Magnetic anisotropy often underpins the short-range order adopted. Half-polarized neutron powder diffraction (pNPD) can be used to determine the local susceptibility tensor on the magnetic sites to quantify the magnetic anisotropy. Combining the techniques of mPDF and pNPD can therefore provide valuable insights into local magnetic behavior. A series of measurements optimized for these techniques are presented as exemplar cases focused on frustrated materials where short-range order dominates, these include measurements to ultra-low temperature (<100 mK) not typically accessible for such experiments.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Interface, bulk and surface structure of heteroepitaxial altermagnetic α-MnTe films grown on GaAs(111)
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Sara Bey, Maksym Zhukovskyi, Tatyana Orlova, Shelby Fields, Valeria Lauter, Haile Ambaye, Anton Ievlev, Steven P. Bennett, Xinyu Liu, Badih A. Assaf
Epitaxial MnTe films have recently seen a spur of research into their altermagnetic semiconducting properties. However, those properties may be extremely sensitive to structural and chemical modifications. We report a detailed investigation of the synthesis of the altermagnet {\alpha}-MnTe on GaAs(111) which reveals the bulk defect structure of this material, the mechanism by which it releases strain from the underlying substrate and the impact of oxidation on its surface. X-ray diffraction measurements show that {\alpha}-MnTe layers with thicknesses spanning 45nm to 640nm acquire lattice parameters different from bulk mostly due to thermal strain caused by the substrate rather than strain from the lattice mismatch. Through high resolution transmission electron microscopy (TEM) measurement, we then unveil a misfit dislocation array at the interface, revealing the mechanism by which lattice strain is relaxed. TEM also reveals a stacking fault in the bulk, occurring along a glide plane parallel to the interface. The combination of TEM with polarized neutron reflectometry measurements finally reveals the impact of oxidation on the chemistry of the surface of uncapped MnTe. Our findings highlight the subtle role of epitaxy in altering the structure of {\alpha}-MnTe providing potential opportunities to tune the altermagnetic properties of this material.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
A Strong-Coupling-Limit Study on the Pairing Mechanism in the Pressurized La$_3$Ni$_2$O$_7$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-17 20:00 EDT
Jia-Heng Ji, Chen Lu, Zhi-Yan Shao, Zhiming Pan, Fan Yang, Congjun Wu
Recently, the bilayer perovskite nickelate La$ _3$ Ni$ _2$ O$ 7$ has been reported to exhibit high-temperature superconductivity (SC) near $ 80$ K under a moderate pressure of about $ 14$ GPa. To investigate the underlying pairing mechanism and symmetry in this complex system, we propose and analyze a mixed spin-$ 1$ and spin-$ \frac{1}{2}$ bilayer $ t$ -$ J$ model in the strong coupling regime. This model explicitly incorporates the crucial role of strong Hund’s coupling, which favors the formation of local spin-triplet states from the two onsite $ E_g$ orbital electrons at half-filling. We further investigate the model using both slave-particle mean-field theory and the density matrix renormalization group method. Our simulation results reveal that the dominate pairing channel is the interlayer one in the $ 3d{x^2-y^2}$ orbital. The Hund’s coupling is shown to enhance SC within a reasonable physical range. Moreover, electron doping strengthens SC by increasing carrier density; in contrast, hole doping weakens SC. These findings offer critical insights into the unconventional SC of pressurized La$ _3$ Ni$ _2$ O$ _7$ and underline the important role of orbital-selective behavior and Hund’s rule.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 9 figures
Energy Cascades in Driven Granular Liquids : A new Universality Class? I : Model and Symmetries
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-17 20:00 EDT
This article deals with the existence and scaling of an energy cascade in steady granular liquid flows between the scale at which the system is forced and the scale at which it dissipates energy. In particular, we examine the possible origins of a breaking of the Kolmogorov Universality class that applies to Newtonian liquids under similar conditions. In order to answer these questions, we build a generic field theory of granular liquid flows and, through a study of its symmetries, show that indeed the Kolmogorov scaling can be broken, although most of the symmetries of the Newtonian flows are preserved.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Fluid Dynamics (physics.flu-dyn)
15 pages, 0 figure
Elastic wave propagation in magneto-active fibre composites
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-17 20:00 EDT
Harold Berjamin, Stephan Rudykh
Fibre-reinforced elastomers are lightweight and strong materials that can sustain large deformations. When filled with magnetic particles, their effective mechanical response can be modified by an external magnetic field. In the present study, we propose an effective theory of fibre-reinforced composite, based on a neo-Hookean elastic response and a linear magnetic law in each phase. The theory is shown suitable to describe the motion of composite cylinders. Furthermore, it is found appropriate for the modelling of fibre-reinforced composites subjected to a permanent magnetic field aligned with the fibres. To reach this result, we use the incremental theory (‘small on large’), in combination with homogenisation theory and the Bloch-Floquet method. This way, we show that wave directivity is sensitive to the application of a permanent magnetic field, whereas the frequency range in which wave propagation is forbidden is not modified by such a load (the band gaps are invariant). In passing, we describe a method to deduce the total stress in the material based on the measurement of two wave speeds. Furthermore, we propose an effective energy function for the description of nonlinear composites made of Yeoh-type generalised neo-Hookean fibres within a neo-Hookean matrix.
Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph)
Spin stiffnesses and stability of magnetic order in the lightly doped two-dimensional Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
Demetrio Vilardi, Pietro M. Bonetti, Walter Metzner
We analyze the density dependence of the spin stiffnesses and the stability of magnetic order with respect to quantum fluctuations in the two-dimensional Hubbard model close to half-filling. The stiffnesses are computed from the spin susceptibility obtained from a random phase approximation in a magnetically ordered state. For a sizable next-to-nearest neighbor hopping amplitude and a moderate Hubbard interaction, the mean-field ground state is a Néel antiferromagnet in the electron doped regime at and above half-filling, and a planar circular spiral state in the hole doped regime below half-filling. Upon electron doping, the Néel stiffness decreases smoothly and not very steeply. By contrast, the in-plane and out-of-plane stiffnesses in the spiral state drop abruptly at half-filling. The out-of-plane stiffness even drops to zero, and then increases again very slowly upon increasing hole doping. At finite temperatures, the Néel-to-spiral transition is shifted into the hole doped regime, the stiffnesses are continuous functions of the density, and they vanish at the transition. For small hole doping, the spin stiffnesses describe the quantum fluctuations only in a small momentum range, which shrinks to zero upon approaching half-filling. Using the above results, we show that the quantum ground state of the lightly electron doped Hubbard model remains Néel ordered, while quantum fluctuations probably destroy the spiral long-range order in the hole doped regime, giving rise to a quantum disordered state with a spin gap.
Strongly Correlated Electrons (cond-mat.str-el)
Dzyaloshinskii-Moriya Interaction and Dipole-Exchange Curvature Effects on the Spin-Wave Spectra of Magnetic Nanotubes
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-17 20:00 EDT
B. Mimica-Figari, P. Landeros, R. A. Gallardo
This work explores spin-wave dynamics in magnetic nanotubes, focusing on the influence of the Dzyaloshinskii-Moriya interaction and curvature. The study uses analytical methods to examine how these factors influence the emergence of nonreciprocity and azimuthal standing waves in nanotubes with longitudinal magnetization along the axis or with a vortex-like magnetization. The interplay between exchange, Dzyaloshinskii-Moriya, and dipolar couplings in determining the chirality of spin waves is discussed. When the magnetization is saturated along an axis, the spin waves propagating along it are symmetric under the inversion of the wave vector. However, magnetochirality, mainly driven by exchange and Dzyaloshinskii-Moriya couplings, is observed in the azimuthal standing modes. In the vortex state, frequency nonreciprocity occurs for waves propagating along the tube, while the azimuthal modes remain reciprocal. For positive Dzyaloshinskii-Moriya interaction, and depending on the helicity of the vortex, the asymmetry induced by the dipolar interaction is reinforced, whereas a negative coupling opposes this asymmetry. The influence of radial anisotropy is also examined. It is found that radial anisotropy reduces the frequency of the modes and shifts the dispersion minimum to a finite wave vector in the vortex state. The properties of modes near zero frequency offer insight into the emergence of chiral magnetic textures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft)
Exotic Quantum States in Spin-1 Bose-Einstein Condensate with Spin-Orbit Coupling in Concentric Annular Traps
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-17 20:00 EDT
We explore the exotic quantum states emerging in the ground state (GS) of a strongly-correlated spin-1 Bose-Einstein condensate confined in two-dimensional concentric annular traps with a spin-orbit coupling (SOC). In the antiferromagnetic case, the GS density manifests various patterns of distributions, including facial-makeup states, petal states, topological fissure states, multiple-half-ring states and property-distinguished vertical and horizonal stripe states. We notice a peculiar phenomenon of density-phase separation in the sense that the variations of density and phase tend to be independent. In ferromagnetic case, the GS exhibits a semi-circular or half-disk status of density embedded with vortices and anti-vortices. The spin distribution can self-arrange into an array of half-skyrmions and we also find a half-antiskyrmion fence separating vortex-antivortex pairs. Our study indicates that one can manipulate the emergence of exotic quantum states via the interplay of the SOC, interaction and potential geometry and the abundant state variations might also provide potential resources for quantum metrology.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
9 pages, 6 figures
Electric field tunable spin-orbit gap in a bilayer graphene/WSe$_{2}$ quantum dot
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-17 20:00 EDT
Hubert Dulisch, David Emmerich, Eike Icking, Katrin Hecker, Samuel Möller, Leonie Müller, Kenji Watanabe, Takashi Taniguchi, Christian Volk, Christoph Stampfer
We report on the investigation of proximity-induced spin-orbit coupling (SOC) in a heterostructure of bilayer graphene (BLG) and tungsten diselenide (WSe$ _2$ ). A BLG quantum dot (QD) in the few-particle regime acts as a sensitive probe for induced SOC. Finite bias and magnetotransport spectroscopy measurements reveal a significantly enhanced SOC that decreases with the applied displacement field, distinguishing it from pristine BLG. We attribute this tunability to an increased layer localization of the QD states on the BLG layer distant to the WSe$ _2$ . Furthermore, our measurements demonstrate a reduced valley $ g$ -factor at larger displacement fields, consistent with a weaker lateral confinement of the QD. Our findings show evidence of the influence of WSe$ _2$ across BLG layers, driven by reduced real-space confinement and increased layer localization at higher displacement fields. This study demonstrates the electrostatic tunability of spin-orbit gap in BLG/WSe$ _2$ heterostructures, which is especially relevant for the field of spintronics and future spin qubit control in BLG QDs.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
7 pages, 5 figures
On the effective magnetostrictive properties of anisotropic magneto-active elastomers in the small-deformation limit
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-17 20:00 EDT
Connor D. Pierce, Kathryn H. Matlack
Magneto-active elastomers (MAEs) are composite materials comprising an elastomer matrix with embedded magnetic particles, endowing the composite with coupled effective magneto-mechanical responses. It is widely reported that anisotropic MAEs exhibit much stronger magneto-mechanical coupling than isotropic MAEs. However, most efforts to model effective magneto-mechanical properties of MAEs via homogenization focused on isotropic microstructures or those with large separations between particles, to use analytical solutions. In this work, we introduce a periodic homogenization approach to compute effective magneto-mechanical properties of anisotropic MAEs, and analyze microstructural features that enhance the magneto-mechanical coupling. Using the finite element method, we numerically determine the effect of particle shape, gap, and voids on the effective stiffness, permeability, and magneto-mechanical coupling tensors for chain-like periodic microstructures. Using insights gained from the full-field simulations, we derive an analytical expression for the magneto-mechanical coupling in the chain direction, in terms of the volume fraction, gap size, and properties of the matrix and particles. Results show that the overall magnetostriction of anisotropic MAEs is most sensitive to the gap between particles and the waviness of the particle chains, with smaller gap sizes and straighter chains yielding higher overall magnetostriction. Simulations also show that while isotropic MAEs elongate in a uniform magnetic field, anisotropic MAEs contract with much larger strain amplitudes, a result of the attractive forces between particles being much stronger in anisotropic MAEs than in isotropic MAEs. Results provide fundamental insights into the mechanisms that govern magneto-mechanical coupling in anisotropic MAEs, and constitute a toolbox of homogenized MAE material properties.
Materials Science (cond-mat.mtrl-sci)
Optimal flock formation induced by agent heterogeneity
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-17 20:00 EDT
Arthur N. Montanari, Ana Elisa D. Barioni, Chao Duan, Adilson E. Motter
The study of flocking in biological systems has identified conditions for self-organized collective behavior, inspiring the development of decentralized strategies to coordinate the dynamics of swarms of drones and other autonomous vehicles. Previous research has focused primarily on the role of the time-varying interaction network among agents while assuming that the agents themselves are identical or nearly identical. Here, we depart from this conventional assumption to investigate how inter-individual differences between agents affect the stability and convergence in flocking dynamics. We show that flocks of agents with optimally assigned heterogeneous parameters significantly outperform their homogeneous counterparts, achieving 20-40% faster convergence to desired formations across various control tasks. These tasks include target tracking, flock formation, and obstacle maneuvering. In systems with communication delays, heterogeneity can enable convergence even when flocking is unstable for identical agents. Our results challenge existing paradigms in multi-agent control and establish system disorder as an adaptive, distributed mechanism to promote collective behavior in flocking dynamics.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Systems and Control (eess.SY), Dynamical Systems (math.DS), Optimization and Control (math.OC), Adaptation and Self-Organizing Systems (nlin.AO)
Projectively implemented altermagnetism in an exactly solvable quantum spin liquid
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-17 20:00 EDT
Avedis Neehus, Achim Rosch, Johannes Knolle, Urban F. P. Seifert
Altermagnets are a new class of symmetry-compensated magnets with large spin splittings. Here, we show that the notion of altermagnetism extends beyond the realm of Landau-type order: we study exactly solvable $ \mathbb{Z}_2$ quantum spin(-orbital) liquids (QSL), which simultaneously support magnetic long-range order as well as fractionalization and $ \mathbb{Z}_2$ topological order. Our symmetry analysis reveals that in this model three distinct types of fractionalized altermagnets (AM$ ^\ast$ )'' may emerge, which can be distinguished by their residual symmetries. Importantly, the fractionalized excitations of these states carry an emergent $ \mathbb{Z}_2$ gauge charge, which implies that they transform \emph{projectively} under symmetry operations. Consequently, we show that altermagnetic spin splittings’’ are now encoded in a momentum-dependent particle-hole asymmetry of the fermionic parton bands. We discuss consequences for experimental observables such as dynamical spin structure factors and (nonlinear) thermal and spin transport.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
7 pages, 2 figures, 10 pages supplemental material