CMP Journal 2025-06-30
Statistics
Nature Materials: 1
arXiv: 59
Nature Materials
Hybrid epoxy-acrylate resins for wavelength-selective multimaterial 3D printing
Original Paper | Mechanical properties | 2025-06-29 20:00 EDT
Ji-Won Kim, Marshall J. Allen, Elizabeth A. Recker, Lynn M. Stevens, Henry L. Cater, Ain Uddin, Ang Gao, Wyatt Eckstrom, Anthony J. Arrowood, Gabriel E. Sanoja, Michael A. Cullinan, Benny D. Freeman, Zachariah A. Page
Structures in nature combine hard and soft materials in precise three-dimensional (3D) arrangements, imbuing bulk properties and functionalities that remain elusive to mimic synthetically. However, the potential for biomimetic analogues to seamlessly interface hard materials with soft interfaces has driven the demand for innovative chemistries and manufacturing approaches. Here, we report a liquid resin for rapid, high-resolution digital light processing (DLP) 3D printing of multimaterial objects with an unprecedented combination of strength, elasticity and resistance to ageing. A covalently bound hybrid epoxy-acrylate monomer precludes plasticization of soft domains, while a wavelength-selective photosensitizer accelerates cationic curing of hard domains. Using dual projection for multicolour DLP 3D printing, bioinspired metamaterial structures are fabricated, including hard springs embedded in a soft cylinder to adjust compressive behaviour and a detailed knee joint featuring ‘bones’ and ‘ligaments’ for smooth motion. Finally, a proof-of-concept device demonstrates selective stretching for electronics.
Mechanical properties, Polymers
arXiv
Quantum Theory of Optical Spin Texture in Chiral Tellurium Lattice
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Pronoy Das, Sathwik Bharadwaj, Jungho Mun, Xueji Wang, Junsuk Rho, Zubin Jacob
The absence of inversion symmetry in chiral tellurium (Te) creates exotic spin textures within its electron waves. However, understanding textured optical waves within Te remains a challenge due to the semi-classical limitations of long-wavelength approximation. To unveil these textured optical waves, we develop a spin-resolved deep-microscopic optical bandstructure for Te analogous to its electronic counterpart. We demonstrate that the degeneracies in this optical bandstructure is lifted by the twisted lattice of Te, which induces optical gyrotropy. Our theory shows excellent agreement with experimental optical gyrotropy measurements. At the lattice level, we reveal that the chirality of Te manifests as deep-microscopic optical spin texture within the optical wave. Our framework uncovers the finite-momentum origin of optical activity and provides a microscopic basis for light-matter interactions in chiral crystalline materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Comment on “The SPOCK equation of state for condensed phases under arbitrary compression” by R. Myhill
New Submission | Other Condensed Matter (cond-mat.other) | 2025-06-30 20:00 EDT
It is shown that the SPOCK equation of state is equivalent to the Variable Polytrope Index equation of state.
Other Condensed Matter (cond-mat.other), Materials Science (cond-mat.mtrl-sci), Geophysics (physics.geo-ph)
4 pages, 0 figures; Comment on doi:https://doi.org/10.1093/gji/ggaf082 (“The SPOCK equation of state for condensed phases under arbitrary compression’’ by R. Myhill (2025), Geophys. J. Int. 241(2), 934-940, this https URL)
Geophysical Journal International 242(2) (2025), ggaf210
A Review on Improving PSC Performance through Charge Carrier Management: Where We Stand and What’s Next?
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Perovskite solar cells (PSCs) represent a breakthrough in photovoltaic technology, combining high power conversion efficiencies (PCEs), ease of fabrication, and tunable optoelectronic properties. However, their commercial viability is limited by critical issues such as charge carrier recombination, interfacial defects, instability under environmental stress, and toxicity of lead-based components. This review systematically examines recent advancements in charge carrier management strategies aimed at overcoming these limitations. Initially, fundamental mechanisms governing carrier generation, separation, transport, and recombination are outlined to provide a clear foundation. The study then delves into an in-depth analysis of carrier lifetime and mobility, evaluating recent methodologies for their enhancement through compositional engineering and structural optimization. Subsequently, trap state passivation techniques and interface engineering approaches are reviewed, with a particular focus on their impact on device stability and efficiency. The review also discusses long-term stability strategies and emerging trends in lead-free and scalable PSC technologies. In this work, recent strategies for charge carrier management are systematically categorized, comparative analyses are provided and synergistic solutions with high potential for real-world implementation are highlighted. By synthesizing data and perspectives from over thirty recent studies, this article offers a comprehensive roadmap for researchers seeking to optimize PSC performance and accelerate their transition toward commercial application.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
45 pages, 15 figures
Canonical Thermodynamics
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-30 20:00 EDT
In the paper, thermodynamics of canonical systems is derived from the multinomial distribution of the occupancy numbers of quantum eigenstates. The cathegorical distribution (i.e. the one-particle distribution) on which the multinomial distribution is based, should be derived from the maximum entropy principle, but, being the multinomial distribution intractable, the paper proposes to take instead the Boltzmann distribution as cathegorical distribution, discussing the reason why the entropy of the multinomial-Boltzmann distribution should closely approximate the entropy achieved by the multinomial distribution equipped with the entropy-maximizing cathegorical distribution. After this, we impose Clausius’ equation on the Shannon entropy of the multinomial-Boltzmann distribution, getting an unexpected result: in general, the Lagrange multiplier $ \beta$ that imposes the energy constraint in constrained entropy maximization turns out to be substantially different from the inverse temperature. To support this unexpected result, the paper presents an example where, with $ \beta$ equal to the inverse temperature, the thermodynamic entropy (i.e. the entropy at a given temperature) of the multinomial-Boltzmann distribution is greater than the Bose-Einstein thermodynamic entropy. However, the latter is derived from entropy maximization with constrained expected energy and expected number of particles, therefore if we plug $ \beta$ equal to the inverse temperature in the multinomial-Boltzmann distribution, then the thermodynamics of the canonical system obtained in this way turns out to be non-compatible with the principle of maximum entropy.
Statistical Mechanics (cond-mat.stat-mech)
Microscopic origin of the magnetic interactions and their experimental signatures in altermagnetic La$_2$O$_3$Mn$_2$Se$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Laura Garcia-Gassull, Aleksandar Razpopov, Panagiotis Peter Stavropoulos, Igor I Mazin, Roser Valentí
Altermagnets (AM) are a recently introduced type of magnets, with no net magnetization like antiferromagnets, but displaying a non-relativistic Zeeman splitting in reciprocal space like ferromagnets. One of the lately discussed models to realize AM is the inverse Lieb lattice (ILL). Initially suggested as a purely theoretical construct, the ILL occurs in real materials such as La$ _2$ O$ _3$ Mn$ _2$ Se$ _2$ . However, AM on the ILL requires 90$ ^\circ$ nearest-neighbor superexchange to be {\it antiferromagnetic} and dominant over the 180$ ^\circ$ next-nearest-neighbor superexchange, in apparent contradiction to the Goodenough-Kanamori-Anderson (GKA) rules. Yet, AM ordering was found to be the ground state in La$ _2$ O$ _3$ Mn$ _2$ Se$ _2$ . Combining ab initio and analytical methods, we determine how direct exchange and superexchange act together to produce a large antiferromagnetic nearest-neigbor coupling. The seeming contradiction with the GKA rules is traced back to the multiorbital character of Mn$ ^{+2}$ ions. By calculating magnon bands, we identify universal signatures of the exchange interactions, suggesting experimental fingerprints.
Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 4 figures + references and supplemental information
Spontaneous Quantum Turbulence in a Newborn Bose-Einstein Condensate via the Kibble-Zurek Mechanism
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-30 20:00 EDT
Seong-Ho Shinn, Matteo Massaro, Mithun Thudiyangal, Adolfo del Campo
The Kibble-Zurek mechanism (KZM) predicts the spontaneous formation of topological defects in a continuous phase transition driven at a finite rate. We propose the generation of spontaneous quantum turbulence (SQT) via the KZM during Bose-Einstein condensation induced by a thermal quench. Using numerical simulations of the stochastic projected Gross-Pitaevskii equation in two spatial dimensions, we describe the formation of a newborn Bose-Einstein condensate proliferated by quantum vortices. We establish the nonequilibrium universality of SQT through the Kibble-Zurek and Kolmogorov scaling of the incompressible kinetic energy.
Quantum Gases (cond-mat.quant-gas), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
6 + 3 pages, 3 + 3 figures
Intertwined Orders and the Physics of High Temperature Superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-30 20:00 EDT
Complex phase diagrams are generic feature of quantum materials that display high temperature superconductivity. In addition to d-wave superconductivity (or other unconventional states), these phase diagrams typically include various forms of charge-ordered phases, including charge-density-waves and/or spin-density waves, and electronic nematic states. In most cases these phases have critical temperatures comparable in magnitude to that of the superconducting state, and appear in a “pseudo-gap” regime. In these systems the high temperature state is not a good metal with well-defined quasiparticles but a “strange metal”. These states typically arise from doping a strongly correlated Mott insulator. With my collaborators we have identified these behaviors as a problem with “Intertwined Orders”. A Pair-density wave is a type of superconducting state which embodies the physics of intertwined orders. Here I discus the phenomenology of intertwined orders and the quantum materials that are known to display these behaviors.
Superconductivity (cond-mat.supr-con)
Expanded text of my talk at the conference on Recent Progress in Many Body Theories 22 (Tsukuba, Japan, September 23-27, 2024), to be publsihed in teh proceedings of the conference; 30 pages, 16 figures, 160 references
A New Experimental Method for Determining the Pinning Energy of an Abrikosov Vortex
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-30 20:00 EDT
We demonstrate a novel method of experimentally addressing the pinning energy of an Abrikosov vortex in high-temperature superconducting thin films. The method is based on our previously published theoretical framework considering the optimization of heterostructural bilayer films. To demonstrate our method, we have estimated the pinning energy of a typical BaZrO$ _3$ -nanocolumn within YBa$ _2$ Cu$ _3$ O$ _{6+x}$ lattice using the experimental data from our previous study. Our calculations result in pinning energy of 0.04 eV/nm for a $ c$ -axis oriented vortex, which is in excellent agreement with a widely used theoretical formula for artificial columnar defects. However, the estimated energy is significantly higher than what has been previously reported for BaZrO$ _3$ -nanocolumns based on magnetic relaxation measurements. We argue that this discrepancy originates from the previously raised issues concerning the reliability of the magnetic relaxation measurements in determining the pinning energy. While the presented study only considers BaZrO$ _3$ -nanocolumns in YBa$ _2$ Cu$ _3$ O$ _{6+x}$ , the demonstrated method is equally applicable to any pinning site and superconducting material. The introduced method of measuring the pinning energy of Abrikosov vortices reduces the present ambiguity around the topic and enables more reliable modeling and design of YBCO based cryogenic memory cells and investigation for their use in quantum applications.
Superconductivity (cond-mat.supr-con)
A canonical approach to quantum fluctuations
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-30 20:00 EDT
Joanna Ruhl, Vanja Dunjko, Maxim Olshanii
We present a canonical formalism for computing quantum fluctuations of certain discrete degrees of freedom in systems governed by integrable partial differential equations with known Hamiltonian structure, provided these models are classical-field approximations of underlying many-body quantum systems. We then apply the formalism to both the 2-soliton and 3-soliton breather solutions of the nonlinear Schrödinger equation, assuming the breathers are created from an initial elementary soliton by quenching the coupling constant. In particular, we compute the immediate post-quench quantum fluctuations in the positions, velocities, norms, and phases of the constituent solitons. For each case, we consider both the white-noise and correlated-noise models for the fluctuation vacuum state. Unlike previous treatments of the problem, our method allows for analytic solutions. Additionally, in the correlated-noise case, we consider the particle-number-conserving (also called $ U(1)$ -symmetry-conserving) Bogoliubov modes, i.e., modes with the proper correction to preserve the total particle number. We find that in most (but not all) cases, these corrections do not change the final result.
Quantum Gases (cond-mat.quant-gas)
13 pages, 7 tables, no figures
Unveiling the Electronic Origin of Anomalous Contact Conductance in Twisted Bilayer Graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Kevin J. U. Vidarte, Caio Lewenkopf, F. Crasto de Lima, R. Hiroki Miwa, Felipe Pérez Riffo, Eric Suárez Morell
This study theoretically investigates the contact conductance in twisted bilayer graphene (TBG), providing a theoretical explanation for recent experimental observations from scanning tunneling microscopy (STM) and conductive atomic force microscopy (c-AFM). These experiments revealed a surprising non-monotonic current pattern as a function of the TBG rotation angle $ \theta$ , with a peak at $ \theta \approx 5^\circ$ , a finding that markedly departs from the well-known magic angle TBG behavior. To elucidate this phenomenon, we develop a comprehensive theoretical and computational framework. Our calculations, performed on both relaxed and rigid TBG structures, simulate contact conductance by analyzing the local density of states across a range of biases and rotational angles. Contrary to the current interpretation, our results demonstrate that the maximum conductance at $ \theta \approx 5^{\rm o}$ is not caused by structural relaxation or AA stacking zone changes. Instead, we attribute this peak to the evolution of the electronic band structure, specifically the shifting of van Hove singularities (vHs) to the Fermi level as the twist angle decreases. We further show that the precise location of this conductance maximum is dependent on the applied bias voltage. This interplay between twist angle, bias, and vHs energy provides a robust explanation for the experimental findings.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
9 pages, 6 figures
Scalable Dip-Coated Bragg Mirrors for Strong Light-Matter Coupling with 2D Perovskites
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Melissa Méndez-Galván, Zaira Saucedo-Chávez, Diana Medrano, Michael Zuarez-Chamba, Yesenia A. García-Jomaso, César L. Ordóñez-Romero, Giuseppe Pirruccio, Arturo Camacho-Guardian, Galo J. A. A. Soler-Illia, Hugo A. Lara-García
We report a scalable and cost-effective method for fabricating high-performance Bragg mirrors using a bottom-up approach that combines evaporation-induced self-assembly (EISA) and dip-coating. The photonic crystals are composed of alternating mesoporous SiO$ _2$ and dense TiO$ _2$ layers, providing a high refractive index contrast ($ \sim$ 0.8). This enables strong reflectance (up to 96%) with as few as five bilayers and precise control of the photonic stop band across the visible spectrum by simply adjusting the deposition parameters. Integration of a thin film of the two-dimensional perovskite (PEA)$ _2$ PbI$ _4$ leads to strong light–matter coupling at room temperature. Angle-resolved reflectance and photoluminescence measurements reveal the formation of upper and lower polariton branches, with a Rabi splitting of 90 meV. The observed polaritonic dispersion is well described by a two-level system and Green’s function formalism. This work demonstrates an efficient strategy for constructing tunable optical cavities using simple solution-based methods. The combination of high optical quality, spectral tunability, and strong coupling performance positions this platform as a promising candidate for low-threshold polariton lasers, nonlinear optics, and integrated optoelectronic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
15 pages
Excitation-detector principle and the algebraic theory of planon-only abelian fracton orders
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Evan Wickenden, Wilbur Shirley, Agnès Beaudry, Michael Hermele
We study abelian planon-only fracton orders: a class of three-dimensional (3d) gapped quantum phases in which all fractional excitations are abelian particles restricted to move in planes with a common normal direction. In such systems, the mathematical data encoding fusion and statistics comprises a finitely generated module over a Laurent polynomial ring $ \mathbb{Z}[t^\pm]$ equipped with a quadratic form giving the topological spin. The principle of remote detectability requires that every planon braids nontrivially with another planon. While this is a necessary condition for physical realizability, we observe - via a simple example - that it is not sufficient. This leads us to propose the $ \textit{excitation-detector principle}$ as a general feature of gapped quantum matter. For planon-only fracton orders, the principle requires that every detector - defined as a string of planons extending infinitely in the normal direction - braids nontrivially with some finite excitation. We prove this additional constraint is satisfied precisely by perfect theories of excitations - those whose quadratic form induces a perfect Hermitian form. To justify the excitation-detector principle, we consider the 2d abelian anyon theory obtained by spatially compactifying a planon-only fracton order in a transverse direction. We prove the compactified 2d theory is modular if and only if the original 3d theory is perfect, showing that the excitation-detector principle gives a necessary condition for physical realizability that we conjecture is also sufficient. A key ingredient is a structure theorem for finitely generated torsion-free modules over $ \mathbb{Z}_{p^k} [t^\pm]$ , where $ p$ is prime and $ k$ a natural number. Finally, as a first step towards classifying perfect theories of excitations, we prove that every theory of prime fusion order is equivalent to decoupled layers of 2d abelian anyon theories.
Strongly Correlated Electrons (cond-mat.str-el), Mathematical Physics (math-ph), Quantum Physics (quant-ph)
76 pages (one-column, double-spaced), 1 figure
Integrable 3-site, tilted, extended Bose-Hubbard model with nearest-neighbour interactions
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-30 20:00 EDT
Extended Bose-Hubbard models have been employed in the study of cold-atom systems with dipolar interactions. It is shown that, for a certain choice of the coupling parameters, there exists an an integrable extended 3-site Bose-Hubbard model with nearest-neighbour interactions. A Bethe Ansatz procedure is developed to obtain expressions for the energy spectrum and eigenstates.
Quantum Gases (cond-mat.quant-gas), Exactly Solvable and Integrable Systems (nlin.SI)
10 pages, 1 figure
Droplet growth, Ostwald’s rule, and emergence of order in Fused in Sarcoma
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-30 20:00 EDT
Farkhad Maksudov (1), Mauro L. Mugnai (2), Laura Dominguez (1 and 3), Dmitrii Makarov (1 and 4), D. Thirumalai (1) ((1) Department of Chemistry, The University of Texas at Austin, (2) Institute of Soft Matter Synthesis and Metrology, Georgetown University, Washington, (3) Departamento de Fisicoquimica, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Coyoacan, CDMX, Mexico, (4) Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin)
The low complexity domain of Fused in Sarcoma (FUS-LC consisting of 214 residues) undergoes phase separation, resulting in a dense liquid-like phase that forms early and slowly matures to reach ordered gel-like state on long time scales. Upon maturation, core-1, comprising of the 57 residues (39-95) in the N-terminus become structured, resulting in the formation of a non-polymorphic fibril. The truncated FUS-LC-C (residues 110-214) construct forms a fibril in which core-2 (residues 112-150) adopts a $ \beta$ -sheet structure. Using coarse-grained monomer SOP-IDP model simulations of FUS-LC, we predict that residues 155-190 in the C-terminal (core-3) form rapidly, followed by core-2, and finally core-1. The time scale of formation of the cores and their stabilities are inversely correlated, as anticipated by the Ostwald’s rule of stages. Unbiased multichain simulations show that the chemical potentials in the two phases are equal and the calculated densities of the dense and dilute phases are in agreement with experiments. The dense phase, which forms by a nucleation mechanism, coarsens over time by a process that is reminiscent of Ostwald ripening. AlphaFold predictions of the core-3 structure and the simulations show that $ \beta$ -strand emerges in the core-3 region early during the droplet formation, and drives the initiation of FUS-LC assembly. The techniques introduced here are general and could be used to probe assembly of other IDPs such as TDP-43, which shares many features with FUS-LC.
Soft Condensed Matter (cond-mat.soft), Biomolecules (q-bio.BM)
Understanding and Controlling V-Doping and S-Vacancy Behavior in Two-Dimensional Semiconductors- Toward Predictive Design
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Shreya Mathela (1), Zhuohang Yu (2), Zachary D. Ward (3), Nikalabh Dihingia (1), Alex Sredenschek (4), David Sanchez (2), Kyle T. Munson (2), Elizabeth Houser (2), Edgar Dimitrov (4), Arpit Jain (2), Danielle Reifsnyder Hickey (1,2,5,6)Humberto Terrones (3), Mauricio Terrones (1,2,4,5), John B. Asbury (1,2) ((1) Department of Chemistry, The Pennsylvania State University, (2) Department of Materials Science and Engineering, The Pennsylvania State University, (3) Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, (4) Department of Physics and Astronomy, The Pennsylvania State University, (5) Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, (6) Materials Research Institute, The Pennsylvania State University)
Doping in transition metal dichalcogenide (TMD) monolayers provides a powerful method to precisely tailor their electronic, optical, and catalytic properties for advanced technological applications, including optoelectronics, catalysis, and quantum technologies. However, doping efficiency and outcomes in these materials are strongly influenced by the complex interactions between introduced dopants and intrinsic defects, particularly sulfur vacancies. This coupling between dopants and defects can lead to distinctly different behaviors depending on doping concentration, presenting significant challenges in the predictable and controlled design of TMD properties. For example, in this work we systematically varied the p-type vanadium (V) doping density in tungsten disulfide (WS2) monolayers and observed a transition in doping behavior. At low concentrations, V-dopants enhance the native optical properties of WS2, as evidenced by increased photoluminescence, without introducing new electronic states. However, at higher concentrations, V-dopants promote the formation of vanadium-sulfur vacancy complexes that generate mid-gap states, with energies that can be precisely tuned by controlling the vanadium concentration. Using a combination of excitation- and temperature-dependent photoluminescence microscopy, atomic-resolution scanning transmission electron microscopy, and first-principles calculations, we identify attractive interactions between p-type V-dopants and n-type monosulfur vacancies. Our results provide mechanistic understanding of how enthalpic dopant-defect interactions versus entropic effects govern the balance between property enhancement versus perturbation of transition metal dichalcogenides and suggest a pathway toward the rational design of doping strategies for next-generation optoelectronic, catalytic, and quantum devices.
Materials Science (cond-mat.mtrl-sci)
29 pages, 5 figures
Hydrodynamic Origin of Friction Between Suspended Rough Particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-30 20:00 EDT
Jake Minten, Bhargav Rallabandi
Tangential interactions between particles play a central role in suspension rheology. We show theoretically that these interactions, often attributed to contact friction, are a direct consequence of fluid flows between rough particles in relative motion. We find that small surface asperities generically lead to localized hydrodynamic sliding forces and torques that can exceed their smooth counterparts by orders of magnitude. A fully analytic thin-film theory shows that these forces grow inversely with the surface separation, significantly more singular than the logarithmic scaling for smooth particles. The impending singularity tightly constrains the particles’ rotation with their translation, recovering a crucial ingredient in dense suspension rheology. Despite their purely hydrodynamic origin, these features resemble several aspects of dry rolling and sliding friction.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
Angular Momentum Fluctuations in the Phonon Vacuum of Symmetric Crystals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Rule Yi, Violet Williams, Benedetta Flebus
Although time-reversal and inversion symmetry constrain the angular momentum of each phonon mode to vanish, we show that the vacuum state of crystals with such symmetries can nevertheless exhibit finite angular momentum fluctuations. These fluctuations arise from quantum coherence between nondegenerate, orthogonally polarized modes and are encoded in the off-diagonal components of the angular momentum operator. Their origin lies in the noncommutativity between the phonon Hamiltonian and angular momentum, which enables time-dependent rotational dynamics even in symmetric vacua. We provide intuitive insight into the coherence underlying this phenomenon by drawing an analogy with the beating between linearly polarized classical waves. Finally, we show that these angular momentum fluctuations produce distinct spectral signatures that can, in principle, be probed via established techniques sensitive to the polarization content and symmetry of lattice excitations, opening an uncharted avenue for accessing and leveraging rotational vacuum correlations in crystalline systems.
Materials Science (cond-mat.mtrl-sci)
Symmetry analysis of cross-circular and parallel-circular Raman optical activity
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Hikaru Watanabe, Rikuto Oiwa, Gakuto Kusuno, Takuya Satoh, Ryotaro Arita
The Raman scattering regarding the circularly-polarized incident and scattered lights is closely related to the circular activity of a given system. We investigate the symmetry of its activity, called the cross-circular and parallel-circular Raman optical activity. The analysis is systematically performed with the magnetic point groups and indicates that the response allows for a useful diagnosis of the symmetry of materials like chirality and (magneto-)axiality. It is also shown that the Stokes and anti-Stokes processes are related to each other by the conserved antiunitary symmetry for the time-reversal operation and that combined with the mirror reflection.
Materials Science (cond-mat.mtrl-sci)
13 pages, 2 figures, 3 tables
Designer Heavy Fermions in Incommensurate $\bf{Nb_3Cl_8}$/Graphene van der Waals Heterostructures
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Yuchen Gao, Wenjie Zhou, Fan Yang, Zhijie Ma, Hansheng Xu, Xinyue Huang, Kenji Watanabe, Takashi Taniguchi, Youguo Shi, Yu Ye
Heavy fermion systems, traditionally realized in rare-earth compounds with limited tunability, have hindered systematic exploration of correlated quantum phenomena. Here, we introduce a general strategy for engineering heavy fermions in incommensurate van der Waals heterostructures by coupling a Mott insulator (Nb$ _3$ Cl$ _8$ ) with itinerant electrons (from monolayer graphene), circumventing strict lattice-matching requirements. Through magnetotransport and slave spin mean-field calculations, we demonstrate the hybridization gap ($ \Delta\approx30$ meV), gate-tunable metal-insulator transition, and band-selective electron effective mass enhancement, hallmarks of Kondo coherence. The heterostructure exhibits nearly order-of-magnitude electron effective mass dichotomy between hybridized and conventional graphene-like regimes, alongside in-plane magnetic field-induced metal-insulator transitions. Top gate-temperature phase mapping reveals competing correlated states, including insulating and hidden-order phases. This work establishes a scalable platform for designing heavy fermion by replacing the itinerant electron materials, with implications for engineering topological superconductivity and quantum criticality in low-dimensional systems.
Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 4 figures
Theory of Magnon Spintronics: Non-Abelian Gauge Theory of Electron Spintronics
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-30 20:00 EDT
Treating the electron as a charged spinon we propose a theory of magnon spintronics, a non-Abelian gauge theory of SU(2)xU(1), which could be viewed as an effective theory of electron spintronics. Just like QED the theory has the U(1) electromagnetic interaction, but the new ingredient is the non-Abelian SU(2) gauge interaction of the magnon with the spinon. A remarkable feature of the theory is the photon-magnon mixing, the mixing between the electromagnetic U(1) gauge boson and the diagonal part of the SU(2) magnon gauge boson. After the mixing we have the massless Abelian magnon and a massive photon, and the doubly charged massive off-diagonal non-Abelian magnons which induce the spin-flip interaction to the spinon. The theory is characterized by three scales. In addition to the correlation length fixed by the mass of the Higgs field it has two different penetration lengths, the one fixed by the mass of the photon which generates the well known Meissner effect and the other fixed by the mass of the off-diagonal magnons which generates the non-Abelian Meissner effect. The non-Abelian structure of the theory naturally accommodates new topological objects, the non-Abrikosov quantized magnonic vortex and non-Abelian magnonic monopole of the Cho-Maison type, as well as the well known Abrikosov vortex. We discuss the physical implications of the non-Abelian gauge theory of the magnon spintronics.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Spin non-Collinear Real-Time Time-Dependent Density-Functional Theory and Implementation in the Modern GPU-Accelerated INQ code
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Jacopo Simoni, Xavier Andrade, Wuzhang Fang, Andrew C.Grieder, Alfredo A. Correa, Tadashi Ogitsu, Yuan Ping
Time-dependent density functional theory (TDDFT) is a theory that describes the time evolution of quantum mechanical many-electron systems under the influence of external time-dependent electric and magnetic fields. INQ is a specially designed software to efficiently solve the real-time TDDFT equations on graphics processing units (GPUs), which aim to overcome the computational limitation of time and size scales of non-equilibrium quantum dynamics. In this work we will present an implementation of non-collinear TDDFT for the INQ code to simulate spin dynamics in real time and discuss the implementation of non-collinear magnetic effects into the code. We will discuss the implementation of exchange-correlation magnetic fields, spin-orbit coupling, and the interaction between the electronic system and external magnetic fields. We will then consider several prototypical examples of spin dynamics in magnetic clusters and solids after light excitation. Potential applications range from the study of real-time dynamics of magnons to ultrafast spin dynamics under linear and circularly polarized laser excitation, as well as spectroscopic signatures such as magnetic circular dichroism and pump-probe Kerr rotation.
Materials Science (cond-mat.mtrl-sci)
Scalable Etch-Free Transfer of Low-Dimensional Materials from Metal Films to Diverse Substrates
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Kentaro Yumigeta (1), Muhammed Yusufoglu (1), Mamun Sarker (2), Rishi Raj (3), Franco Daluisio (4), Richard Holloway (1), Howard Yawit (1), Thomas Sweepe (1), Julian Battaglia (1), Shelby Janssen (1), Alex C. Welch (4), Paul DiPasquale (1), K. Andre Mkhoyan (3), Alexander Sinitskii (2), Zafer Mutlu (1,5,6) ((1) Department of Materials Science & Engineering, University of Arizona, Tucson, Arizona, USA (2) Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA (3) Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota, USA (4) Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona, USA (5) Department of Electrical and Computer Engineering, University of Arizona, Tucson, Arizona, USA (6) Department of Physics, University of Arizona, Tucson, Arizona, USA)
Low-dimensional materials hold great promises for exploring emergent physical phenomena, nanoelectronics, and quantum technologies. Their synthesis often depends on catalytic metal films, from which the synthesized materials must be transferred to insulating substrates to enable device functionality and minimize interfacial interactions during quantum investigations. Conventional transfer methods, such as chemical etching or electrochemical delamination, degrade material quality, limit scalability, or prove incompatible with complex device architectures. Here, a scalable, etch-free transfer technique is presented, employing Field’s metal (51% In, 32.5% Bi, and 16.5% Sn by weight) as a low-melting-point mechanical support to gently delaminate low-dimensional materials from metal films without causing damage. Anchoring the metal film during separation prevents tearing and preserves material integrity. As a proof of concept, atomically precise graphene nanoribbons (GNRs) are transferred from Au(111)/mica to dielectric substrates, including silicon dioxide (SiO_2) and single-crystalline lanthanum oxychloride (LaOCl). Comprehensive characterization confirms the preservation of structural and chemical integrity throughout the transfer process. Wafer-scale compatibility and device integration are demonstrated by fabricating GNR-based field-effect transistors (GNRFETs) that exhibit room-temperature switching with on/off current ratios exceeding 10^3. This method provides a scalable and versatile platform for integrating low-dimensional materials into advanced low-dimensional materials-based technologies.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Investigation of magnetic and magneto-transport properties in non-centrosymmetric antiferromagnetic semimetal GdGaSi
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Manikantha Panda, Prabuddha Kant Mishra, Sonali S Pradhan, V. Kanchana, Tapas Paramanik
In this work, we investigated the magneto-transport and magnetic properties of GdGaSi, having non-centrosymmetric tetragonal structure, with space group $ I4_1md$ . Our theoretical results are supported by experimental studies. First-principles calculations reveal that GdGaSi is an antiferromagnetic semimetallic system, characterized by dominant electron-type charge carriers. In addition, the possible nontriviality of the crossing at the Fermi energy is consistent with isostructural LaPtSi-structured materials. The compound shows robust antiferromagnetic (AFM) ordering with a Néel temperature of 19 K, and spin-reorientation signature below $ T_N$ . The semimetallic nature with positive magnetoresistance ($ \simeq$ 2% at 2 K and 8 T) is observed from the magnetotransport data, having electrons as majority charge carrier, established from the Hall measurements. The strong correlation in magnetism and transport is supported by various observations, like (1) concordant transitions in $ M(T)$ and $ \rho (T)$ data, (2) change in the concentration and mobility of electron below $ T_N$ , and (3) splitting of Kohler’s plots in the two branches across the transition. Thus, our findings establish GdGaSi as a material with intertwined magnetic and transport degrees of freedom, within noncentrosymmetric lattice.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Prediction of A15 Tilt Grain Boundary Structures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Wenwen Zou, Zihan Su, Juan Zhang, Kai Jiang
In this work, we present a theoretical method to predict all coincidence site lattice (CSL) tilt grain boundaries (GBs) in A15, especially high-$ \Sigma$ CSL GBs. This method includes a modified Farey diagram (MFD) and a computational framework based on the 3D phase field crystal model. Applied to [001] CSL symmetric tilt grain boundaries (STGBs) in A15, this method identifies building blocks of A15 GBs, known as structural units (SUs). The MFD predicts the quantity and proportion of SUs within GBs. The developed computational approach further determines the arrangement of these SUs. The predictive rule reveals the SU arrangement of A15 [001] CSL STGBs.
Materials Science (cond-mat.mtrl-sci)
The Bulk Penetration of Edge Properties in Two-Dimensional Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Edges are essential for the mechanical, chemical, electronic, and magnetic properties of two-dimensional (2D) materials. Research has shown that features assigned to edges are not strictly localized but often penetrate the bulk to some degree. However, mechanical edge properties, such as edge energies and stresses, are typically assigned at the system level, with spatial bulk penetrations that remain unknown. Here, we use density-functional tight-binding simulations to study how deep various edge properties spatially penetrate the 2D bulk. We study nine different edges made of four materials: graphene, goldene, boron nitride, and molybdenum disulfide. By investigating edge energies, edge stresses, and edge elastic moduli, we find that although the edge properties typically originate near edges, they still penetrate the bulk to some degree. An utmost example is goldene with a staggered edge, whose edge properties penetrate the bulk nanometer-deep. Our results caution against associating system-level edge properties too strictly with the edge, especially if those properties are further used in continuum models.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 6 figures
Physical Review B, 111, 235445 (2025)
The Structural Behavior of Physisorbed Metallenes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Kameyab Raza Abidi, Pekka Koskinen
Atomically thin metallenes have properties attractive for applications, but they are intrinsically unstable and require delicate stabilization in pores or other nano-constrictions. Substrates provide solid support, but metallenes’ wanted properties can only be retained in weak physisorption. Here, we study the 45 physisorbed, atomically thin metallene structures in flat and buckled lattices using a sequential multi-scale model based on density-functional theory calculations. The lattices are mostly buckled but flat for a handful of elements such as Na, K, Rb, Ag, Au, and Cd, depending on physisorption strength. Moreover, under certain conditions, the structure can be controlled by applying biaxial tensile stress parallel or an electric field normal to the surface. The stress reduces the threshold of adhesion strength required to flatten a buckled lattice, and the electric field can be used to increase that threshold controllably. Our results help provide fundamental information about the structures of physisorbed metallenes and suggest means to control them at will by suitable substrate choice or tuning of experimental parameters.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages, 4 figures
Nanoscale Adv., 2025,7, 3426-3431
Observation of entanglement in a cold atom analog of cosmological preheating
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-30 20:00 EDT
Victor Gondret, Clothilde Lamirault, Rui Dias, Léa Camier, Amaury Micheli, Charlie Leprince, Quentin Marolleau, Jean-René Rullier, Scott Robertson, Denis Boiron, Christoph I. Westbrook
We observe entanglement between collective excitations of a Bose-Einstein condensate in a configuration analogous to particle production during the preheating phase of the early universe. In our setup, the oscillation of the inflaton field is mimicked by the transverse breathing mode of a cigar-shaped condensate, which parametrically excites longitudinal quasiparticles with opposite momenta. After a short modulation period, we observe entanglement of these pairs which demonstrates that vacuum fluctuations seeded the parametric growth, confirming the quantum origin of the excitations. As the system continues to evolve, we observe a decrease in correlations and a disappearance of non-classical features, pointing towards future experimental probes of the less understood interaction-dominated regime.
Quantum Gases (cond-mat.quant-gas), General Relativity and Quantum Cosmology (gr-qc), Pattern Formation and Solitons (nlin.PS), Quantum Physics (quant-ph)
4+3 pages, 4 figures
Flocking with random non-reciprocal interactions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-30 20:00 EDT
Jiwon Choi, Jae Dong Noh, Heiko Rieger
Flocking is ubiquitous in nature and emerges due to short or long range alignment interactions among self-propelled agents. Two unfriendly species that anti-align or even interact non-reciprocally show more complex collective phenomena, ranging from parallel and anti-parallel flocking over runand chase behavior to chiral phases. Whether flocking or any of these collective phenomena can survive in the presence of a large number of species with random non-reciprocal interactions remained elusive so far. As a first step here the extreme case of a Vicsek-like model with fully random nonreciprocal interactions between the individual particles is considered. As soon as the alignment bias is of the same order as the random interactions the ordered flocking phase occurs, but deep within this phase, the random non-reciprocal interactions can still support global chiral and oscillating states in which the collective movement direction rotates or oscillates slowly. For short-range interactions, moreover, even without alignment bias self-organized cliques emerge, in which medium size clusters of particles that have predominantly aligning interactions meet accidentally and stay together for macroscopic times. These results may serve as a starting point for the study of multi-species flocking models with non-random but complex non-reciprocal inter-species interactions.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
9 pages, 7 figures
Non-Relativistic Anisotropic Magnetoresistance with Collinear and Non-Collinear Magnetic Order
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Philipp Ritzinger, Ondřej Sedláček, Jakub Železný, Karel Výborný
Anisotropic magnetoresistance (AMR) arises from symmetry lowering of the conductivity tensor induced by magnetic order. In simple ferromagnets, AMR is a relativistic effect, relying on spin-orbit interaction (SOC). Here, we demonstrate that a comparable symmetry lowering can also occur in a non-relativistic limit. Using tight-binding models, density functional theory calculations, and Boltzmann transport theory, we investigate systems with multiple magnetic sublattices, including both collinear and non-collinear antiferromagnets, as well as ferrimagnetic configurations. We show that AMR and related anisotropies can emerge purely from magnetic order, without the need for SOC, and may reach significant magnitudes. The findings are supported by case studies on toy-model lattices and real materials such as MnN, Mn$ _3$ Sn, and are further interpreted using a symmetry analysis based on Neumann’s principle. Material candidates that exhibit non-relativistic anisotropic magnetoresistance are identified by symmetry analysis applied to entries in the MAGNDATA database.
Materials Science (cond-mat.mtrl-sci)
11 pages, 8 figures, 1 table
Exceptional thermoelectric properties in Na$_2$TlSb enabled by quasi-1D band structure
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Øven A. Grimenes (1), Ole M. Løvvik (2), Kristian Berland (1) ((1) Norwegian University of Life Sciences, (2) SINTEF Sustainable Energy Technology)
Quasi-low-dimensional band structures in bulk high-symmetry materials can exhibiting density of states (DOS) profiles akin to those of low-dimensional materials. A particular striking example is the full-Heusler compound Na$ _2$ TlSb, with valence band energy isosurfaces consisting of intersecting 2D-dimensional pockets forming a box-like structure, with the sides individually akin to the energy isosurfaces arising in one-dimensional (1D) quantum wells. The combination of high velocities and rapidly increasing DOS with energy is extremely promising for thermoelectric applications. However, these beneficial properties could in principle be counteracted by high electronic scattering rates, and the benefits of for instance band convergence has been questioned precisely because of increased scattering rates. It is therefore critical to understand the electronic scattering nature of low-dimensional systems. In the current study, describing electronic transport properties of Na$ 2$ TlSb from first principles, we found that electronic scattering rates remained modest despite the high DOS. This was caused by the intricate interplay between several effects: (i) delocalized energetic isosurfaces giving rise to large momentum scattering paths with low wavefunction overlap, reducing the scattering probability; (ii) a high DOS resulting in a high free-carrier screening; (iii) a large portion of the scattering paths within the flat energy isosurfaces keeps the electron group velocity nearly constant, reducing the effective relaxation rates. The high velocity and modest relaxation time result in a high carrier mobility, which, together with the high DOS and beneficial DOS profile, results in excellent electron transport properties. Combined with an ultra-low $ \kappa\ell$ of $ <1$ reported in literature, we predict a thermoelectric figure of merit ranging from 2.4 at 300 K to a maximum of 4.4 at 600 K.
Materials Science (cond-mat.mtrl-sci)
10 pages, 8 figures, Supplemental Material
A Generic Platform for Designing Fractional Chern Insulators: Electrostatically Engineered Rashba Materials
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Bokai Liang, Wei Qin, Zhenyu Zhang
We present a generic platform for designing topological flat bands through applying an artificially designed electrostatic superlattice potential to a thin film with Rashba spin-orbit coupling. Utilizing many-body exact diagonalization, we show that the lowest flat band can host fractional Chern insulator states at filling factor $ n = 1/3$ and $ 2/3$ . Notably, these fractional charge states present robustly in a broad regime of the parameter space. We further discuss the potential realistic materials and the associated experimental conditions required to realize these compelling theoretical predictions. Our findings establish a versatile platform for engineering topological flat bands and exploring topologically nontrivial correlated states.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 4 figures and Supplemental material
Chiral Quantum Droplet in a Spin-Orbit Coupled Bose Gas
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-30 20:00 EDT
We report the formation of chiral quantum droplet in a spin-orbit coupled Bose gas, where the system turns to a self-bound droplet when moving towards a particular direction and remains gaseous otherwise. The chirality arises from the breaking of Galilean invariance by spin-orbit coupling, which enables the system to dynamically adjust its condensation momentum and spin polarization in response to its velocity. As a result, only towards a specific moving direction and beyond a critical velocity, the acquired spin polarization can trigger collective interactions sufficient for self-binding and drive a first-order transition from gas to droplet. We have mapped out a phase diagram of droplet, gas and their coexistence for realistic spin-orbit coupled 39K mixtures with tunable moving velocity and magnetic detuning. Our results have revealed the emergence of chirality in spin-orbit coupled quantum gases, which shed light on general chiral phenomena in moving systems with broken Galilean invariance.
Quantum Gases (cond-mat.quant-gas)
6 pages, 3 figures
Ultra-small Mode Volume Polariton Condensation via Precision $He^+$ Ion Implantation
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Y. C. Balas, X. Zhou, E. Cherotchenko, I. Kuznetsov, S.K. Rajendran, G.G. Paschos, A.V. Trifonov, A. Nalitov, H. Ohadi, P.G. Savvidis
We present a novel method for generating potential landscapes in GaAs microcavities through focused $ He^{+}$ implantation. The ion beam imprints micron-scale patterns of non-radiative centers that deplete the exciton reservoir and form a loss-defined potential minimum. Under non-resonant pumping, the resulting traps have a lateral size $ \le 1.2 ~\mathrm{\mu m}$ and a three-dimensional mode volume of only $ \approx 0.6 ~ \mathrm{\mu m^3}$ , small enough to to support a single polariton condensate mode. The implantation process maintains strong coupling and provides lithographic ($ < 300 ~ \mathrm{nm}$ ) resolution. These loss-engineered traps effectively overcome the micrometer-scale limitations of conventional microcavity patterning techniques, opening new avenues for device development and polariton research within the quantum regime.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
Vortex structure and intervortex interaction in superconducting structures with intrinsic diode effect
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-30 20:00 EDT
A. V. Putilov, D. V. Zakharov, A. Kudlis, A. S. Mel’nikov, A. I. Buzdin
We demonstrate that the intrinsic superconducting-diode effect can strongly reshape Abrikosov vortices in non-centrosymmetric superconductor/ferromagnet hybrid structures. The Ginzburg-Landau (GL) theory accounting for the spin-orbit and exchange-field effects predicts a chiral distortion of the superfluid velocity, non-central interaction forces and resulting torque in a vortex-antivortex pair, and anisotropy of the Bean-Livingston barrier. These closed-form results are fully confirmed by time-dependent GL numerical simulations carried out with a fourth-order least-squares finite-difference solver, which captures equilibrium single vortex configuration in realistic mesoscopic geometries. The analysis shows that the cubic gradient term shifts vortex cores by an amount proportional to the in-plane exchange field and simultaneously generates a lateral torque that can rotate entire vortex ensembles, showing how spin-orbit coupling (SOC) and the exchange field enable breakdown of the vortex–antivortex symmetry in a finite-size sample. By combining transparent analytics with quantitative numerics, the work provides the hallmarks of vortex physics in superconducting structures with an intrinsic diode effect and supplies concrete guidelines for designing non-reciprocal superconducting circuits, fluxonic logic elements, and kinetic-inductance devices.
Superconductivity (cond-mat.supr-con)
Wurtzite AlScN/AlN Superlattice Ferroelectrics Enable Endurance Beyond 1010 Cycles
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Ruiqing Wang, Feng Zhu, Haoji Qian, Jiuren Zhou, Wenxin Sun, Siying Zheng, Jiajia Chen, Bochang Li, Yan Liu, Peng Zhou, Yue Hao, Genquan Han
Wurtzite ferroelectrics are rapidly emerging as a promising material class for next-generation non-volatile memory technologies, owing to their large remanent polarization, intrinsically ordered three-dimensional crystal structure, and full compatibility with CMOS processes and back-end-of-line (BEOL) integration. However, their practical implementation remains critically constrained by a severe endurance bottleneck: under conditions where the remanent polarization (2Pr) reaches or exceeds 200 uC/cm^2, devices typically undergo catastrophic failure before reaching 10^8 cycles. Here, we report a vacancy-confining superlattice strategy that addresses this limitation, achieving reliable ferroelectric switching beyond 10^10 cycles while preserving saturated polarization (2Pr >= 200 uC/cm^2). This is achieved by embedding periodic ultrathin AlN layers within AlScN films, forming wurtzite AlScN/AlN superlattices, in conjunction with a dynamic recovery protocol that actively stabilizes the defect landscape throughout repeated cycling. Atomic-resolution imaging and EELS spectrum imaging technique, supported by first-principles calculations, reveal a self-regulated defect topology in which nitrogen vacancies are spatially confined by heterostructure energy barriers and dynamically re-trapped into energetically favorable lattice sites. This dual spatial-energetic confinement mechanism effectively inhibits both long-range percolative migration and local defect clustering, enabling such an ultrahigh endurance exceeding 10^10 cycles and limiting polarization degradation to below 3% after 10^9 cycles. These findings establish nitrogen vacancy topology stabilization as a foundational design principle for reliable operation of wurtzite ferroelectrics, providing a scalable and CMOS-compatible platform for future high-endurance ferroelectric memory technologies.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
30 pages 11 figures
Microscopic approach to the quantized light-matter interaction in semiconductor nanostructures: Complex coupled dynamics of excitons, biexcitons, and photons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Hendrik Rose, Stefan Schumacher, Torsten Meier
We present a microscopic and fully quantized model to investigate the interaction between semiconductor nanostructures and quantum light fields including the many-body Coloumb interaction between photoexcited electrons and holes. Our approach describes the coupled dynamics of the quantum light field and single and double electron-hole pairs, i.e., excitons and biexcitons, and exactly accounts for Coulomb many-body correlations and carrier band dispersions. Using a simplified yet exact approach, we study a one-dimensional two-band system interacting with a single-mode, two-photon quantum state within a Tavis$ \unicode{x2013}$ Cummings framework. By employing an exact coherent factorization scheme, the computational complexity is reduced significantly enabling numerical simulations. We also derive a simplified model which includes only the bound $ 1s$ -exciton and biexciton states for comparison. Our simulations reveal distinct single- and two-photon Rabi oscillations, corresponding to photon-exciton and exciton-biexciton transitions. We demonstrate, in particular, that biexciton continuum states significantly modify the dynamics in a way that cannot be captured by simplified models which consider only bound states. Our findings emphasize the importance of a comprehensive microscopic modeling in order to accurately describe quantum optical phenomena of interacting electronic many-body systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Controllable Non-reciprocity in Multi-sphere Loaded Chiral Resonator
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Maxime Ardisson, Guillaume Bourcin, Julien Haumant, Romain Lebrun, Isabella Boventer, Vincent Castel
Cavity magnonics explores the hybridization of photons and magnons within microwave resonators. One of the hallmarks of these systems is their ability to exhibit non-reciprocity, which is a key feature for radio frequency (RF) applications. One way to control non-reciprocal behaviors in cavity magnonics is the design of chiral cavities that allow selective coupling between photons and magnons depending on their polarization. However, a built-in chiral platform to harness and control non-reciprocity remains to be achieved. Here, we experimentally demonstrate controllable non-reciprocity (with an absolute isolation ratio reaching 46 dB) in a chiral resonator loaded with multiple yttrium iron garnet spheres. We develop a theoretical model of the S-parameters based on input-output formalism which highlights the links between the phases occurring in the system and its non-reciprocal behavior. Controllable non-reciprocity in cavity magnonics could enable the development of programmable isolators, circulators, and RF switches with improved performance. Such developments could pave the way toward more versatile and scalable information processing systems.
Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
Coherent coupling of YBCO superconducting resonators and 100-nm-thick YIG films
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-30 20:00 EDT
Alberto Ghirri, Mattia Cavani, Claudio Bonizzoni, Marco Affronte
In cavity magnonics, magnon-photon hybridization has been widely investigated for both fundamental studies and applications. Planar superconducting resonators operating at microwave frequencies have demonstrated the possibility to achieve high couplings with magnons by exploiting the confinement of the microwave field in a reduced volume. Here we report a study of the coupling of high-Tc YBCO superconducting waveguides with 100-nm-thick YIG magnetic films. We study the evolution of mode frequencies at different temperatures and extract the coupling strength of hybrid magnon-photon modes. We show that the experimental results can be reproduced using a simple model in which the temperature dependence of the penetration depth accounts for the evolution of the polaritonic spectrum.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
19 pages, 4 figures
Symmetry oscillations sensitivity to SU(2)-symmetry breaking in quantum mixtures
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-30 20:00 EDT
S. Musolino, M. Albert, P. Vignolo, A. Minguzzi
In one-dimensional bosonic quantum mixtures with SU(2)-symmetry breaking Hamiltonian, the dynamical evolution explores different particle exchange symmetry sectors. For the case of infinitely strong intra-species repulsion, the hallmark of such symmetry oscillations are time modulations of the momentum distribution [Phys. Rev. Lett. 133, 183402 (2024)], an observable routinely accessed in experiments with ultracold atoms. In this work we show that this phenomenon is robust in strongly interacting quantum mixtures with arbitrary inter-species to intra-species interaction strength ratio. Taking as initial state the ground state of the SU(2) symmetric Hamiltonian and time-evolving with the symmetry breaking Hamiltonian, we analyze how the amplitude and frequency of symmetry oscillations, and thus of the momentum distribution oscillations, depend on the strength of the symmetry-breaking perturbation. We find that the set of symmetry sectors which are coupled during the time evolution is dictated by the spin-flip symmetry of the initial state and show that the population of the initial state may vanish periodically, even in the thermodynamic limit, thus revealing the robustness and universality of the symmetry oscillations.
Quantum Gases (cond-mat.quant-gas)
11 pages, 6 figures
From Density Functional Theory to Spin Hamiltonians: Magnetism in $d^5$ Honeycomb Compound OsCl$_3$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Magnetism in strongly correlated honeycomb systems with $ d^5$ electronic configuration has garnered significant attention due to its potential to realize the Kitaev spin liquid state, characterized by exotic properties. However, real materials exhibit not only Kitaev exchange interactions but also other magnetic exchanges, which may drive the transition from a spin liquid phase to a long-range ordered ground state. This work focuses on modelling the effective spin Hamiltonian for two-dimensional (2D) honeycomb magnetic systems with $ d^5$ electronic configurations. The Hubbard-Kanamori (HK) Hamiltonian equipped with spin-orbit coupling and electron correlations is considered where onsite energies and hopping parameters, preserving the crystal symmetry, are extracted from the first principles Density functional theory (DFT) calculations. Exact diagonalization (ED) calculations for the HK Hamiltonian on a two-site cluster are performed to construct the effective magnetic Hamiltonian. The ground-state magnetic properties are explored using the semi-classical Luttinger-Tisza approach. As a representative case, the magnetic ground state of the $ d^5$ honeycomb system OsCl$ _3$ is investigated, and the variation of magnetic exchange parameters with respect to the correlation strength (U) and Hund’s coupling ($ J_H$ ) is analyzed. The magnetic ground state exhibits zigzag antiferromagnetic ordering for a chosen value of $ U$ and $ J_H$ , consistent with DFT results. This study provides insight into the magnetism of OsCl$ _3$ and offers a computationally efficient alternative to traditional energy-based methods for calculating exchange interactions for strongly correlated systems.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
7 pages, 4 figures. Accepted for publication in the Journal of Chemical Sciences
Signatures of rigidity and second sound in dipolar supersolids
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-06-30 20:00 EDT
G. A. Bougas, T. Bland, H. R. Sadeghpour, S. I. Mistakidis
We propose a dynamical protocol to probe the rigidity and phase coherence of dipolar supersolids by merging initially separated fragments in quasi-one-dimensional (1D) double-well potentials. Simulations based on the extended Gross-Pitaevskii equation reveal distinct dynamical signatures across phases. Supersolids exhibit damped crystal oscillations following barrier removal, with the damping rate reflecting superfluid connectivity. A phase-imprinted jump additionally triggers metastable dark solitons, which excites second sound, as revealed by an out-of-phase drift between the droplet lattice and the superfluid background. Our results show a realizable path to dynamically detect the second sound and rigidity of supersolids, as well as to realize and probe soliton formation.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
6 pages, 6 figures
Long-range systems, (non)extensivity, and the rescaling of energies
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-30 20:00 EDT
Systems with long-range interactions have seen a surge of interest in the past decades. In the wake of this surge, the use of a system size dependent rescaling, sometimes termed “Kac prescription,” of the long-range pair potential has seen widespread use. This ad hoc modification of the Hamiltonian makes the energy extensive, but its physical justification and implications are a frequent source of confusion and misinterpretation. After all, in real physical $ N$ -body systems, the pair interaction strength does not scale with the number $ N$ of constituents. This article presents, at an introductory level, scaling arguments that provide a clear physical interpretation of the “Kac prescription” for finite systems as well as in the thermodynamic limit.
Statistical Mechanics (cond-mat.stat-mech)
8 pages, 3 figures; pedagogical paper aimed at graduate students and newcomers to the field of long-range interacting systems
Phase-modulated superconductivity via altermagnetism
New Submission | Superconductivity (cond-mat.supr-con) | 2025-06-30 20:00 EDT
Shuntaro Sumita, Makoto Naka, Hitoshi Seo
Stimulated by recent interest in altermagnets, a novel class of antiferromagnets with macroscopic time-reversal symmetry breaking, we investigate the coexistence of altermagnetism and superconductivity. By developing a Ginzburg–Landau theory based on microscopic models, we show that a phase-modulated Fulde–Ferrell superconducting state is stabilized via altermagnetic spin splitting, in contrast to the typical amplitude-modulated states that occur under a uniform Zeeman field. We apply our framework to different models: a two-sublattice model with altermagnetic order, a continuum model with an anisotropic Zeeman field mimicking altermagnetic spin splitting, and a conventional square-lattice model with two kinds of anisotropic Zeeman fields. Our results indicate that the multi-sublattice structure is crucial for realizing this exotic superconductivity, and highlight spin-split altermagnets as a promising platform for exploring phase-modulated superconductivity without external magnetic fields.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
17 pages, 1 table and 7 figures
Dissipative Kondo physics in the Anderson Impurity Model with two-body losses
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Matthieu Vanhoecke, Naoto Tsuji, Marco Schirò
We study a dissipative version of the Anderson Impurity model, where an interacting impurity is coupled to a fermionic reservoir and exposed to Markovian dissipation in the form of two-body losses. Using a self-consistent hybridization expansion based on the Non-Crossing Approximation (NCA) we compute the dynamics of the impurity, its steady-state and spectral function. We show that the interplay between strong Coulomb repulsion and correlated dissipation gives rise to robust signatures of Kondo physics both at weak and strong losses. These include a strongly suppressed spin relaxation rate, displaying a characteristic Kondo-Zeno crossover and a spectral function where doublon band is quickly destroyed by dissipation while the coherent Kondo peak remains visible for weak losses, then disappears at intermediate values and finally re-emerge as the system enters in the Kondo-Zeno regime. As compared to the case of single particle losses we show that two-body dissipation protects Kondo physics. The picture obtained with NCA is confirmed by numerical simulations of exact dynamics on finite-size chains. We interpret these results using a dissipative Schrieffer-Wolff transformation, which leads to an effective Kondo model with residual impurity-bath losses which are suppressed by strong correlations or strong losses.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
18 pages, 9 figures
Entropy of self-avoiding branching polymers: mean field theory and Monte Carlo simulations
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-06-30 20:00 EDT
Davide Marcato, Achille Giacometti, Amos Maritan, Angelo Rosa
We study the statistics of branching polymers with excluded-volume interactions, by modeling them as single self-avoiding trees on a generic regular periodic lattice with coordination number $ q$ . Each lattice site can be occupied at most by one tree node, and the fraction of occupied sites can vary from dilute to dense conditions. By adopting the statistics of directed trees as a proxy for that of undirected trees without internal loops and by an exact mapping of the model into a field theory, we compute the entropy and the mean number of branch-nodes within a mean field approximation and in the thermodynamic limit. In particular, we find that the mean number of branch-nodes is independent of both the lattice details and the lattice occupation, depending only on the associated chemical potential. Monte Carlo simulations in $ d=2,3,4$ provide evidence of the remarkable accuracy of the mean field theory, more accurate for higher dimensions.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
18 pages, 6 figures, submitted for publication
Skyrmions of Frustrated Quantum Dimer Systems
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Fletcher Williams, David Dahlbom, Hao Zhang, Shruti Agarwal, Kipton Barros, Cristian D. Batista
Magnetic skyrmions are topologically protected solitons observed in various classes of real magnets. In two-dimensional systems, where the target space of local magnetization values is the two-sphere $ S^2$ , skyrmion textures are classified by the homotopy classes of two-loops $ S^2$ in $ S^2$ : $ \Pi_2(S^2) \cong Z$ . Here, we demonstrate that more general topological skyrmion textures emerge in the classical limit of quantum dimer systems, where the phase space of the relevant classical theory is $ \mathbb{CP}^{N-1}$ (with $ N=4$ for the case of interest), because the relevant second homotopy group, $ \Pi_2(\mathbb{CP}^{N-1}) \cong Z$ for $ N\geq 2$ , remains unchanged. Building on the framework established by Zhang et al. (2023), we consider a classical limit based on SU(4) coherent states, which preserve intra-dimer entanglement. We show that the zero-temperature phase diagram of frustrated spin-dimer systems on a bilayer triangular lattice with weak inter-dimer coupling includes two magnetic-field-induced $ \mathbb{CP}^{3}$ skyrmion crystal phases.
Strongly Correlated Electrons (cond-mat.str-el)
15 pages, 11 figures
Site-polarized Mott phases competing with a correlated metal in twisted WSe$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Siheon Ryee, Lennart Klebl, Gautam Rai, Ammon Fischer, Valentin Crépel, Lede Xian, Angel Rubio, Dante M. Kennes, Roser Valentí, Andrew J. Millis, Antoine Georges, Tim O. Wehling
Twisted WSe$ _2$ hosts superconductivity, metal-insulator phase transitions, and field-controllable Fermi-liquid to non-Fermi-liquid transport properties. In this work, we use dynamical mean-field theory to provide a coherent understanding of the electronic correlations shaping the twisted WSe$ _2$ phase diagram. We find a correlated metal competing with three distinct site-polarized correlated insulators; the competition is controlled by interlayer potential difference and interaction strength. The insulators are characterized by a strong differentiation between orbitals with respect to carrier concentration and effective correlation strength. Upon doping, a strong particle-hole asymmetry emerges, resulting from a Zaanen-Sawatzky-Allen-type charge-transfer mechanism. The associated charge-transfer physics and proximity to a van Hove singularity in the correlated metal sandwiched between two site-polarized insulators naturally explains the interlayer potential-driven metal-to-insulator transition, particle-hole asymmetry in transport, and the coherence-incoherence crossover in $ 3.65^\circ$ twisted WSe$ _2$ .
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Terahertz time-domain signatures of the inverse Edelstein effect in topological-insulator|ferromagnet heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Genaro Bierhance, Chihun In, Enzo Rongione, Reza Rouzegar, Oliver Gueckstock, Emanuele Longo, Laëtitia Baringthon, Nicolas Reyren, Romain Lebrun, Jean-Marie George, Polychronis Tsipas, Martin Wolf, Tom S. Seifert, Roberto Mantovan, Henri Jaffrès, Athanasios Dimoulas, Tobias Kampfrath
Three-dimensional topological insulators possess topologically protected surface states with spin-momentum locking, which enable spin-charge-current interconversion (SCI) by the inverse Edelstein effect (IEE). However, it remains experimentally challenging to separate the surface-related IEE from the bulk-type inverse spin Hall effect (ISHE). Here, we search for distinct time-domain signatures of the two SCI phenomena in a $ \mathcal{F}$ |TI model stack of a ferromagnetic-metal layer $ \mathcal{F}$ (Co and Fe) and a topological-insulator layer TI (Bi$ _2$ Te$ _3$ , SnBi$ _2$ Te$ _4$ and Bi$ _{1-x}$ Sb$ _x$ with $ x$ = 0.15 and 0.3), where the focus is on Bi$ _2$ Te$ _3$ . A femtosecond laser pulse serves to induce a transient spin voltage $ \mu_s^{\mathcal{F}}$ in $ \mathcal{F}$ and, thus, drive an ultrafast spin current out of $ \mathcal{F}$ . SCI results in a transverse charge current with a sheet density $ I_c$ that is detected by sampling the emitted terahertz electric field. Analysis of the dynamics of $ I_c(t)$ vs time $ t$ relative to $ \mu_s^{\mathcal{F}}(t)$ reveals two components with distinct time scales: (i) a quasi-instantaneous response and (ii) a longer-lived response with a relaxation time of 270 fs, which is independent of the chosen $ \mathcal{F}$ material. Component (i) is consistently ascribed to the ISHE. In contrast, we interpret component (ii) as a signature of interfacial spin accumulation and the IEE at the $ \mathcal{F}$ /Bi$ _2$ Te$ _3$ interface, with a fraction of $ < 10^{-2}$ of the incident spins participating. This assignment is fully consistent with respect to its dynamics and magnitude. We rate other possible signal contributions, such as spin trapping in intermediate states, as less likely. Our results show that the femtosecond dynamics of photocurrents provide important insights into the mechanisms of spin transport and SCI in $ \mathcal{F}$ |TI stacks.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Enhanced thermoelectric effects in a driven one-dimensional system
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
C. X. Zhang, Alessandro Braggio, Alessandro Romito, Fabio Taddei
We investigate the thermoelectric properties of a one-dimensional quantum system in the presence of an external driving. We employ Floquet scattering theory to calculate linear-response stationary thermoelectric figures of merit in a single-channel conductor subjected to a periodically varying delta-like potential barrier. We include a step barrier in one of the leads as a model of a nanoscale inhomogeneous semiconducting system. In the absence of a step barrier, we found that the external driving can strongly enhance the Seebeck coefficient, particularly at low temperatures, with a relative increase with respect to the static condition reaching up to 200% at large frequencies. In the presence of a step barrier, we found that the thermoelectric Onsager coefficient for the driven case is also enhanced with respect to the static case with a significant effect at low temperatures when the chemical potential is within the gap of the semiconductor. Our results demonstrate that external driving can be used to tune and enhance the thermoelectric capabilities of low-electron-density nanodevices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 11 figures
Role of long-range dipolar interactions in the simulation of the properties of polar crystals using effective atomic potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Miao Yu, Fernando Gómez-Ortiz, Louis Bastogne, Jin-Zhu Zhao, Philippe Ghosez
Driven by novel approaches and computational techniques, second-principles atomic potentials are nowadays at the forefront of computational materials science, enabling large-scale simulations of material properties with near-first-principles accuracy. However, their application to polar materials can be challenging, particularly when longitudinal-optical phonon modes are active on the material, as accurately modeling such systems requires incorporating the long-range part of the dipole-dipole interactions. In this study, we challenge the influence of these interactions on the properties of polar materials taking BaTiO$ _3$ as paradigmatic example. By comparing models with and without the long-range part of the electrostatic contributions in a systematic way, we demonstrate that even if these interactions are neglected, the models can still provide an overall good description of the material, though they may lead to punctual significant artifacts. Our results propose a pathway to identify when an atomistic potential may be inadequate and needs to be corrected through the inclusion of the long-range part of dipolar interactions.
Materials Science (cond-mat.mtrl-sci)
Multislice Hollow Ptychography for Simultaneous Atomic-Layer-Resolved 3D Structural Imaging and Spectroscopy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
Electron matter interactions in electron microscopy produce both elastic and inelastic scattering, forming the basis for imaging and spectroscopy. However, the integration of electron energy loss spectroscopy (EELS) with 4D-STEM and electron ptychography remains challenging because of detector geometry conflicts. Song et al. solved this issue by introducing a hollow type pixelated detector that enables hollow ptychography and allows low angle electrons to go through to the EELS spectrometer. The single-slice approach of hollow ptychography proves effective for 2D thin materials but struggles with multiple scattering in thicker specimens. Here, we introduce multislice hollow ptychography (MHP), a robust imaging modality that overcomes these limitations by accounting for multiple scattering. MHP enables high-resolution structural imaging from hollow diffraction patterns while remaining compatible with simultaneous EELS acquisition. It potentially can provide sub-angstrom lateral resolution at intermediate doses and supports full 3D atomic-layer reconstruction at ultrahigh doses, with up to 70% of total electrons available for spectroscopy. This flexible framework facilitates correlative 3D imaging and chemical mapping in complex materials, including interfaces, defects, and dopants.
Materials Science (cond-mat.mtrl-sci), Instrumentation and Detectors (physics.ins-det), Optics (physics.optics)
13 pages, 5 main figures, 8 supplementary figures, 4 supplementary tables. Introduces a new imaging modality ‘Multislice Hollow Ptychography’ (MHP) for simultaneous 3D structural imaging and spectroscopy. Experimental data and simulations are based on PrScO3
Topological Defect Propagation to Classify Knitted Fabrics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-30 20:00 EDT
Daisuke S. Shimamoto, Keiko Shimamoto, Sonia Mahmoudi, Samuel Poincloux
Knits and crochets are mechanical metamaterials with a long history and can typically be produced from a single yarn. Despite the simplicity of the manufacturing process, they exhibit a wide range of structural configurations with diverse mechanical properties and application potential. Although there has been recent growing interest in textile-based metamaterials, a rigorous topological characterization of what makes a structure knittable has been lacking. In this paper, we introduce a general criterion based on topological constraints that distinguishes knits and crochets from other textile structures. We demonstrate how the introduction of topological defects and their propagation makes this classification practical. Our approach highlights a fundamental link between manufacturing processes and structural fragility. Within this framework, we show how the rationalization of defect propagation unlocks the design of fabrics with controllable resistance to damage.
Soft Condensed Matter (cond-mat.soft), Mathematical Physics (math-ph)
14 pages, 11 figures
Modeling the g-factors, hyperfine interaction and optical properties of semiconductor QDs: the atomistic and eight-band $k \cdot p$ approaches
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Krzysztof Gawarecki, Alina Garbiec, Jakub Stanecki, Michał Zieliński
We present a detailed comparative study of two important theoretical approaches: atomistic sp$ ^3$ d$ ^5$ s$ ^\ast$ tight-binding and continuum eight-band $ k \cdot p$ methods, for modeling the spin and optical properties of quantum dots (QDs). Our investigation spans key physical observables, including single-particle energy levels, g-factors, exciton radiative lifetimes, and hyperfine-induced Overhauser field fluctuations. We perform our calculations for self-assembled InGaAs/GaAs QD systems as representative case studies. While both methods yield qualitatively consistent trends, quantitative discrepancies arise due to different treatment of atomistic details, strain effects, and confinement. We introduce targeted corrections to the eight-band $ k \cdot p$ framework, including a modified deformation potential scheme and adjusted remote-band contributions, to improve agreement with atomistic results, especially for electron g-factors and single-particle energies. Furthermore, we validate the eight-band implementation of hyperfine interactions by benchmarking it against the tight-binding model, showing reasonable convergence for both electrons and holes. Our results establish criteria for selecting the appropriate modeling framework based on the desired physical accuracy and computational efficiency in spin-optical studies of semiconductor QDs.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Computational Physics (physics.comp-ph)
Decoherence of Majorana qubits by 1/f noise
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Abhijeet Alase, Marcus C. Goffage, Maja C. Cassidy, Susan N. Coppersmith
Qubits based on Majorana Zero Modes (MZMs) in superconductor-semiconductor nanowires have attracted intense interest as a platform for utility-scale quantum computing. These qubits have been predicted to show extremely low error rates due to topological protection of the MZMs, where decoherence processes have been thought to be exponentially suppressed by either the nanowire length or the temperature. However, here we show that 1/f noise, which is ubiquitous in semiconductors, gives rise to a previously unexplored mechanism for Majorana qubit decoherence. The high frequency components of this noise causes quasiparticle excitations in the bulk of the topological superconductor, which in turn result in qubit errors that increase with the length of the nanowire. We calculate the probability of quasiparticle excitation for disorder-free nanowires in the presence of 1/f noise and show that this mechanism limits the decoherence times of the MZM qubits currently being developed to less than a microsecond even for perfectly uniform nanowires with no disorder. This decoherence time is significantly shorter than the time to implement quantum gates using this technology and is also shorter than the decoherence times of qubits in other leading solid-state architectures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
29 pages, 9 figures
Spin Seebeck Effect of Triangular-lattice Spin Supersolid
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Yuan Gao, Yixuan Huang, Sadamichi Maekawa, Wei Li
Using our developed thermal tensor-network approach, we investigate the spin Seebeck effect (SSE) of the triangular-lattice quantum antiferromagnet hosting spin supersolid phase. We focus on the low-temperature scaling of normalized spin current $ \tilde{I}_S$ through the interface, and benchmark our approach on 1D Heisenberg chain, with the negative spinon spin current reproduced. In addition, we find an algebraic scaling $ \tilde{I}_S \sim T^{\alpha}$ with varying exponent $ \alpha$ in the Tomonaga-Luttinger liquid phase. On the triangular lattice, spin frustration dramatically enhances the low-temperature SSE, with characteristic spin-current signatures distinguishing different magnetic phases. Remarkably, we discover a persistent spin current $ \tilde{I}_S$ in the spin supersolid phase, which saturates to a non-zero value in the low-temperature limit and can be ascribed to the Goldstone-mode-mediated spin supercurrents. Moreover, a universal scaling $ \tilde{I}_S \sim T^{d/z}$ is found at the U(1)-symmetric polarization quantum critical points. These distinct quantum spin transport traits - particularly the sign reversal and characteristic temperature dependence in SSE - provide sensitive experimental probes for investigating spin-supersolid compounds such as Na$ _2$ BaCo(PO$ _4$ )$ _2$ . Moreover, our results establish spin supersolids as a tunable quantum platform for spin caloritronics in the ultralow-temperature regime.
Strongly Correlated Electrons (cond-mat.str-el)
19 pages, 12 figures
Quantum-geometric dipole: a topological boost to flavor ferromagnetism in flat bands
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-06-30 20:00 EDT
Lei Chen, Sayed Ali Akbar Ghorashi, Jennifer Cano, Valentin Crépel
Robust flavor-polarized phases are a striking hallmark of many flat-band moiré materials. In this work, we trace the origin of this spontaneous polarization to a previously overlooked quantum-geometric quantity: the quantum-geometric dipole. Analogous to how the quantum metric governs the spatial spread of wavepackets, we show that the quantum-geometric dipole sets the characteristic size of particle-hole excitations, e.g. magnons in a ferromagnet, which in turn boosts their gap and stiffness. Indeed, the larger the particle-hole separation, the weaker the mutual attraction, and the stronger the excitation energy. In topological bands, this energy enhancement admits a lower bound within the single-mode approximation, highlighting the crucial role of topology in flat-band ferromagnetism. We illustrate these effects in microscopic models, emphasizing their generality and relevance to moiré materials. Our results establish the quantum-geometric dipole as a predictive geometric indicator for ferromagnetism in flat bands, a crucial prerequisite for topological order.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
8+8 pages, 3+2 figures
Structure-Property Correlations in Sb, Ge, and Ga Doped AlFe$_2$B$_2$ for Magnetocaloric Applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-06-30 20:00 EDT
R. Preyadarshini, S. Kavita, Ashutosh Kumar, D. Sivaprahasam
This study investigates the effects of Sb, Ge, and Ga doping in AlFe$ _2$ B$ _2$ on magnetic and magneto-caloric properties. Samples of AlFe$ _2$ B$ _2$ and AlFe$ _{1.9}$ M$ _{0.1}$ B$ _2$ (M= Ge, Ga and Sb) with 20% excess Al were synthesized by arc melting, and the powder processed were investigated for their phase constituents, microstructure, magnetic and magneto-caloric effect. The parent compounds prepared showed the AlFe$ _2$ B$ _2$ phase with a FeB secondary phase. However, in Sb and Ga-doped samples, an additional impurity phase, Al$ _{13}$ Fe$ _4$ , was observed apart from FeB, while in Ge-doped, only the AlB$ _2$ impurity phase was present. The Curie temperature of AlFe$ _2$ B$ _2$ is 277 K, increasing with Sb, Ge, and Ga doping to 287,K, 297,K, and 296,K, respectively. The magnetization ($ M$ ) is also higher with Ge and Ga addition in the 100-300,K range; however, with Sb doping, the $ M$ decreases significantly compared to parent AlFe$ _2$ B$ _2$ . The magnetic entropy change under 2,T reached 2.93 JKg$ ^{-1}$ K$ ^{-1}$ near 274,K in AlFe$ _2$ B$ _2$ , which decreases to 2.53 JKg$ ^{-1}$ K$ ^{-1}$ and 1.92 JKg$ ^{-1}$ K$ ^{-1}$ with Ge and Ga, respectively. With Sb doping, the MC change was affected dramatically to 0.32 JKg$ ^{-1}$ K$ ^{-1}$ . However, the relative cooling power of Ge doped is the same as that of parent AlFe$ _2$ B$ _2$ . This research advances the understanding of the relationship between doping elements and magnetic properties in AlFe$ _2$ B$ _2$ and opens pathways for designing magneto-caloric materials with tailored magnetic characteristics.
Materials Science (cond-mat.mtrl-sci)
8 Pages, 7 Figures and 2 Tables
Mesoscale properties of protein clusters determine the size and nature of liquid-liquid phase separation (LLPS)
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-06-30 20:00 EDT
Gonen Golani, Manas Seal, Mrityunjoy Kar, Anthony A. Hyman, Daniella Goldfarb, Samuel Safran
The observation of Liquid-Liquid Phase Separation (LLPS) in biological cells has dramatically shifted the paradigm that soluble proteins are uniformly dispersed in the cytoplasm or nucleoplasm. The LLPS region is preceded by a one-phase solution, where recent experiments have identified clusters in an aqueous solution with 102-103 proteins. Here, we theoretically consider a core-shell model with mesoscale core, surface, and bending properties of the cluster shell and contrast two experimental paradigms for the measured cluster size distributions of the Cytoplasmic Polyadenylation Element Binding-4 (CPEB4) and Fused in Sarcoma (FUS) proteins. The fits to the theoretical model and earlier electron paramagnetic resonance (EPR) experiments suggest that the same protein may exhibit hydrophilic, hydrophobic, and amphiphilic conformations, which act to stabilize the clusters. We find that CPEB4 clusters are much more stable compared to FUS clusters, which are less energetically favorable. This suggests that in CPEB4, LLPS consists of large-scale aggregates of clusters, while for FUS, clusters coalesce to form micron-scale LLPS domains.
Soft Condensed Matter (cond-mat.soft)
Main Text and Supplementa
Commun Phys 8, 226 (2025)
Correlation Enhanced Electron-Phonon Coupling in FeSe/SrTiO$_3$ at a Magic Angle
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-06-30 20:00 EDT
Qiang Zou, Antik Sihi, Basu Dev Oli, Mercè Roig, Daniel Agterberg, Michael Weinert, Lian Li, Subhasish Mandal
While a predictive theory for unconventional superconductivity in Fe-based superconductors remains elusive, an extensively debated aspect is the interaction between phonons and strongly correlated electrons, and its potential role in the pairing mechanism. Here, through the combination of first principles dynamical mean field theory calculations and epitaxial growth of the single-layer FeX (X=Se, S, Te) on SrTiO$ _3$ (STO)(001) substrate, which facilitates the controlled distortion of the FeX$ _4$ tetrahedron, we demonstrate an unique superconducting dome where the superconducting gap peaks at a `magic’ angle of the FeX$ _4$ tetrahedron and the electron-phonon coupling (EPC) for the A$ _{1g}$ mode is maximized for the FeSe film. Our findings uncover a significant role of electronic correlations in strengthening Cooper pairing in unconventional superconductors by enhancing EPC.
Strongly Correlated Electrons (cond-mat.str-el)