Other Condensed Matter · Cross-listed from physics.optics
All-optical nonlinear phase modulation in open semiconductor microcavities
Fedor A. Benimetskiy, Paul M. Walker, Anthony Ellul et al. (+8 more)
We report a significant advancement in ultra low power light-by-light phase modulation using open
semiconductor microcavities in the strong light-matter coupling regime. We achieve cross-phase modulation of up to 247$\pm$17 mrad per particle between
laser beams attenuated to single-
photon average intensities. This breakthrough extends the potential for
quantum information processing and nonlinear
quantum optics in strongly coupled light-matter systems, setting a new
benchmark in the field without relying on atom-like emitters. Our findings suggest promising new avenues for scalable
quantum optical technologies.
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All authors Fedor A. Benimetskiy, Paul M. Walker, Anthony Ellul, Oleksandr Kyriienko, Martina Morassi, Aristide Lemaître, Tommi Isoniemi, Maurice S. Skolnick, Jacqueline Bloch, Sylvain Ravets, Dmitry N. Krizhanovskii
Statistical Mechanics · Cross-listed from quant-ph
Far-from-equilibrium thermodynamics of non-Abelian thermal states
Franklin L. S. Rodrigues and Eric Lutz
Noncommutativity of observables is a central feature of
quantum physics. It plays a fundamental role in the formulation of the uncertainty principle for complementary variables and strongly affects the laws of thermodynamics for systems with noncommuting, that is, non-Abelian, conserved quantities. We here derive nonequilibrium generalizations of the second law of thermodynamics in the form of fluctuation relations, both for mechanically and thermally driven
quantum systems. We identify a non-Abelian contribution to the energy and
entropy balances, without which these relations would be violated. The latter term can be controlled to enhance both work extraction and nonequilibrium currents compared to what is obtained in commuting thermodynamics. These findings demonstrate that noncommutativity maybe a useful thermodynamic resource.
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Materials Science
Electronic and thermal properties of the phase-change memory material, Ge2Sb2Te5, and results from spatially resolved transport calculations
Kishor Nepal, Aashish Gautam, Ridwan Hussein et al. (+4 more)
We report new insights into the electronic, structural, and transport (heat and charge) properties of the phase-change
memory material Ge2Sb2Te5. Using realistic structural models of Konstantinou et. al. [Nat. Commun. 10, 3065 (2019)], we analyze the
topology, electronic states, and
lattice dynamics with density functional methods, including hybrid-functional calculations and machine-learned interatomic potentials. The Kohn-Sham orbitals near the
Fermi level display a strong electron-
phonon coupling, and exhibit large energy fluctuations at room temperature. The conduction tail states exhibit larger
phonon-induced fluctuations than the valence tail states. To resolve transport at the atomic scale, we employ space-projected electronic conductivity and site-projected thermal conductivity methods. Local analysis of heat transport highlights the role of filamentary networks dominated by Te, with Sb and Ge making progressively smaller contributions.
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All authors Kishor Nepal, Aashish Gautam, Ridwan Hussein, Konstantinos Konstantinou, Stephen. R. Elliott, Chinonso Ugwumadu, David A. Drabold
Strongly Correlated Electrons
Finite temperature dopant-induced spin reorganization explored via tensor networks in the two-dimensional $t$-$J$ model
Yintai Zhang, Aritra Sinha, Marek M. Rams et al. (+1 more)
We study the two-dimensional $t$–$J$ model at finite temperature directly in the thermodynamic limit using purification represented by an infinite projected entangled-pair state (iPEPS). We reach temperatures down to $T/t=0.1$ and hole concentrations up to $1-n\simeq0.25$, and provide
benchmark thermodynamic-limit results for the specific heat, uniform susceptibility, and charge compressibility. We identify a susceptibility maximum $T^\ast$ that tracks the buildup of short-range antiferromagnetism and a shallow compressibility enhancement upon cooling in the same doping window. To expose the underlying microscopic mechanism, we introduce dopant-conditioned multi-point correlators that quantify how holes reorganize nearby exchange: single holes weaken adjacent
antiferromagnetic bonds, while nearest-neighbor hole pairs produce a cooperative response that reinforces antiferromagnetism on the parallel plaquette edge. Over the same parameter window, $d$-wave pairing correlations remain short-ranged. These results provide experiment-compatible thermodynamic-limit
benchmarks and establish dopant-conditioned correlators as incisive probes of finite-temperature
spin-texture reorganization in doped Mott
insulators.
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All authors Yintai Zhang, Aritra Sinha, Marek M. Rams, Jacek Dziarmaga
Materials Science
Correlative Analysis of Iron-Driven Structural, Optical, and Magnetic Properties in Natural Biotite Crystals
Raphaela de Oliveira, Yara Galvão Gobato, Ronei C. de Oliveira et al. (+9 more)
Biotite
crystals are phyllosilicate trioctahedral micas with the general chemical formula K(Mg,Fe)3AlSi3O10(OH)2 that form a solid-solution series with iron-poor phlogopite and iron-rich annite endmembers. With a wide band gap energy and a layered structure with free surface charges, biotite nanosheets can be readily obtained by cleavage methods and used as dielectrics in nanodevice fabrication for the next generation of electronics and energy harvesting. Here, a comprehensive study of biotite samples with different iron concentrations and oxidation states is presented. Structural, optical, magneto-optical, and
magnetic characterizations were performed using several experimental techniques, including state-of-the-art synchrotron-based techniques, to correlate the iron chemistry (content and oxidation state) with the macroscopic properties of both minerals. The study reveals a nanoscale-homogeneous Fe distribution via synchrotron X-ray fluorescence mapping, defect-mediated optical transitions modulated by Fe3+/Fe2+ ratios, and temperature-dependent
magnetic transitions from paramagnetism to competing ferro-/
antiferromagnetic interactions. Furthermore, the use of these biotite
crystals as substrates for ultrathin
heterostructures incorporating monolayer (ML) MoSe2 is explored by magneto photoluminescence at cryogenic temperatures. The results show that the presence of iron
impurities in different oxidation states significantly impacts the valley properties for ML-MoSe2. Overall, these findings offer a comprehensive interpretation of the physical properties of bulk biotites in a correlative approach, serving as a robust reference for future studies aiming to explore biotites in their ultrathin form.
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All authors Raphaela de Oliveira, Yara Galvão Gobato, Ronei C. de Oliveira, José R. de Toledo, Verônica C. Teixeira, Angelo Malachias, Cesar R. Rabahi, Chunwei Hsu, Adilson J. A. de Oliveira, Herre. S. J. van der Zant, Ingrid D. Barcelos, Alisson R. Cadore
Materials Science
AtomWorld: A Benchmark for Evaluating Spatial Reasoning in Large Language Models on Crystalline Materials
Taoyuze Lv, Alexander Chen, Fengyu Xie et al. (+7 more)
Large
language models (LLMs) have shown promising potential in scientific research, enabling tasks ranging from knowledge
retrieval to property prediction. Existing science
benchmarks mainly focus on perceptual or knowledge-based tasks, largely ignoring the modelling tasks, a fundamental starting point for any real scientific research. For materials science, constructing and manipulating atomic structures is one of the most creative and least automated steps. In this work, we introduce AtomWorld, a
benchmark designed to evaluate the abilities of LLMs on structure modifications. The
benchmark includes ten fundamental actions under four widely used modelling categories, enabling verifiable evaluation metrics. We find that Claude Opus 4.6 generally performs the best. While the success rate decreases markedly with increasing modelling complexity, with particularly low success rates (below 12% for rotation) for operations involving complex spatial relations. Our results suggest that contemporary LLMs are better suited as copilots for materials structure modelling rather than fully unsupervised autonomous scientific
agents. Beyond evaluation, AtomWorld also serves as a testbed and playground for developing future structure-aware models, including reinforcement learning and agentic approaches.
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All authors Taoyuze Lv, Alexander Chen, Fengyu Xie, Chu Wu, Jeffrey Meng, Dongzhan Zhou, Yingheng Wang, Bram Hoex, Zhicheng Zhong, Tong Xie
Strongly Correlated Electrons
Repulsive-Interaction-Driven Topological Superconductivity in a Landau Level Coupled to an $s$-Wave Superconductor
Koji Kudo, Ryota Nakai, Hiroki Isobe et al. (+2 more)
A two-dimensional topologically nontrivial state of noninteracting electrons, such as the surface state of a three-dimensional topological
insulator, is predicted to realize a topological
superconductor when proximity-coupled to an ordinary $s$-wave
superconductor. In contrast, noninteracting electrons partially occupying a Landau level, with Rashba
spin-orbit coupling that lifts the
spin degeneracy, fail to develop topological superconductivity under similar proximity coupling in the presence of the conventional Abrikosov
vortex lattice. We demonstrate, through exact diagonalization, that introducing in this model a repulsive interaction between electrons induces topological superconductivity at half-filled Landau level for a range of parameters. This appears rather surprising because a repulsive interaction is expected to inhibit, not promote, pairing, but suggests an appealing principle for realizing topological superconductivity: proximity-coupling a composite
Fermi liquid to an ordinary $s$-wave
superconductor.
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All authors Koji Kudo, Ryota Nakai, Hiroki Isobe, J. K. Jain, Kentaro Nomura
Mesoscale and Nanoscale Physics
Stability of graphene hyperbolic pseudospheres under harsh conditions
T. P. C. Klaver, R. Gabbrielli, V. Tynianska et al. (+2 more)
We demonstrate the high stability of simulated
graphene hyperbolic pseudospheres under large externally imposed deformations and high temperature annealing.
Hyperbolic pseudospheres are produced in a two-step Molecular Dynamics simulation process. First, carbon atoms are forced down a thin three-dimensional volume of a chosen shape. During this extrusion process the carbon atoms form a precursor to
graphene that is unrealistically less stable than graphite or diamond. Then the unstable carbon structure is annealed inside the thin volume at high temperature, turning the carbon into realistic polycrystalline, curved
graphene. Point defects naturally appear in numbers and places that stabilize the
graphene in the desired shape, without high residual stresses. We applied this new methodology to the creation of
graphene hyperbolic pseudosphere surfaces, which reproduce analogs to some aspects of classical or
quantum gravity. The free edges of the pseudosphere cause bending of the
graphene. When these free edges are removed from the simulations by attaching periodic flat
graphene sheets to the pseudosphere edges, the carbon atoms assume positions just some tenths of Å from the mathematical
hyperbolic pseudosphere surface. In demanding tests of their stability, the
hyperbolic pseudospheres proved stable against $20^\circ$ shearing or $20\%$ elongation and then being released, which eventually raised their temperatures by $\sim 300 \ \text{K}$. Our methodology is relatively easy to use and offers a practical way to create simulated curved
graphene surfaces of almost any shape. It allows for thorough testing in advance of the stability of
graphene shapes that are to be produced experimentally.
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All authors T. P. C. Klaver, R. Gabbrielli, V. Tynianska, A. Iorio, D. Legut
Mesoscale and Nanoscale Physics
Spin injection of exciton-polaritons with halide perovskites at room temperature
Elena Sendarrubias Arias-Camisón, Maksim Lednev, Jorge Cuadra et al. (+6 more)
Exciton-polaritons, hybrid
photon-
exciton quasiparticles, constitute a useful platform for the study of light-matter interaction and nonlinear photonic applications. In this work, we realize a monolithic Tamm-plasmon microcavity
embedding a thin film of two-dimensional halide perovskites with a tunable
polymer spacer that controls the
exciton-
photon detuning. Angle-resolved optical spectroscopy at room temperature reveals the lower polariton branch dispersions in the linear regime for several detunings. Under circularly polarized, quasi-resonant
laser excitation, the
spin injection of
excitons and their relaxation towards the lower polariton branch demonstrates its preservation. The observed
spin-polarized emission is consistent with the fast decay of polaritons:
spin relaxation mechanisms become inefficient during this short time. Our results provide promising insights into the
spin control of polaritonic devices, including
chiral lasers and switches.
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All authors Elena Sendarrubias Arias-Camisón, Maksim Lednev, Jorge Cuadra, Raúl Gago, Luis Viña, Francisco José García Vidal, Johannes Feist, Ferry Prins, Carlos Antón Solanas
Strongly Correlated Electrons
Pronounced orbital-selective electron-electron correlation and electron-phonon coupling in V2Se2O
Mingzhe Hu, Ziyin Song, Jingwen Cheng et al. (+16 more)
Orbital-selective many-body effects, in which electrons occupying different orbitals experience distinct interaction strengths, play a crucial role in correlated multiorbital materials. However, these effects usually manifest in a complex manner, obscuring their microscopic origins. Here, by combining angle-resolved photoemission spectroscopy measurements with theoretical calculations, we reveal pronounced orbital selectivity in both electron-electron correlation and electron-
phonon coupling in the van der Waals material V2Se2O. Electron correlation induces distinct bandwidth renormalization exclusively in the V d_xy-derived band, while the bands mainly composed of the other d orbitals remain essentially unrenormalized. Orbital-resolved analyses identify that the filling number and the bandwidth are decisive factors governing orbital-dependent correlation. Simultaneously, the d_(xz/yz)-derived band exhibits a sharp kink anomaly, arising from enhanced coupling to high-energy
phonon modes dominated by oxygen vibrations. Such pronounced orbital selectivity positions V2Se2O as a rare and prototypical platform for unravelling the microscopic mechanisms of orbital-selective electron-electron and electron-
phonon interactions, and offers guiding principles for the design of correlated multiorbital materials.
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All authors Mingzhe Hu, Ziyin Song, Jingwen Cheng, Gexing Qu, Zhanghuan Li, Yu Huang, Jundong Zhu, Guangyu Zhang, Dacheng Tian, Lan Chen, Zhijun Tu, Hechang Lei, Xiaoping Ma, Huaixin Yang, Zhongxu Wei, Genfu Chen, Hongming Weng, Tian Qian, Hang Li
Soft Condensed Matter
Robust Kirkwood-Buff inversion in complex mixtures via reciprocal-space methods
Rémi Busselez
Understanding the relationship between microscopic structure and macroscopic thermodynamic properties is a central challenge in the study of complex fluids. The Kirkwood-Buff (KB) theory offers an elegant and powerful framework for bridging this gap by relating integrals over pair correlation functions to measurable thermodynamic quantities. In multicomponent systems, KB integrals connect directly to derivatives of thermodynamic potentials, including chemical potentials derivatives, partial molar volumes, and isothermal compressibility. While several computational methods exist to estimate KB integrals from molecular simulations, their application often demands careful treatment of finite-size effects and explicit extrapolation to the thermodynamic limit. Recently, alternative strategies based on the analysis of partial structure factors in reciprocal space have been proposed. Unlike real-space approaches, reciprocal-space methods avoid the additional truncation artifacts associated with direct integration or fluctuations in subensemble. They evaluate density fluctuations across the entire simulation box, fully accounting for periodic boundary conditions rather than relying on subdomains. As a result, these methods offer a compelling alternative, providing enhanced numerical stability for estimating KB integrals in complex mixtures. In this work, we extend, compare and validate these methods using binary and quaternary Lennard-Jones mixtures, as well as realistic molecular systems such as hexane-ethanol, water-urea, and aqueous NaCl mixtures. Our results provide practical guidelines for computing KB integrals and associated thermodynamic properties from canonical ensemble simulations, including recommendations on reciprocal-space extrapolation, uncertainty estimation, and linear
algebra formulations of thermodynamic derivatives.
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Quantum Gases
Symmetry and Self-Bound Droplets in Dipolar Molecular Gases
D. Baillie
Recent experiments with degenerate molecular gases dressed by elliptically polarized microwave fields have enabled new control of dipolar interactions via engineered anisotropy. We reveal a
symmetry structure of the dipolar interaction that generates degeneracies among the interaction parameters, enabling a classification of spatial
symmetries and
equilibrium shapes of the gases. Exploiting these
symmetries, we analyze solutions including beyond-meanfield
quantum fluctuations, and develop a complementary variational theory. We map out the phase diagram of self-bound droplets and characterize their widths, energies, and densities.
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Materials Science
Investigating into mechanisms of high temperature strength of refractory high-entropy alloys
Sai Anandhi Seetharaman, Soumyadipta Maiti, Ambesh Gupta et al. (+1 more)
The yield strength plateau of two BCC refractory high
entropy alloys (RHEAs) - MoNbTaVW and MoNbTaW was examined through hybrid Monte Carlo and molecular dynamics (MC/MD) simulations. By analyzing atomic diffusivities derived from vacancy formation and migration energies around the edge dislocation cores, the number of critical atomic swaps were calculated at different temperatures. Using hybrid MC/MD simulations of these critical swaps, we demonstrate that above 1400K, the stress required to move the dislocations gets saturated, indicating the effect of Dynamic Strain Ageing (DSA) via cross core motion. Further simulations on random solid solutions (0 MC swaps) revealed a similar plateau effect at the intermediate temperatures. This was attributed to the additional athermal stress arising from
lattice distortions due to solid solution strengthening. Our findings suggest that the yield strength plateau results from an interplay between the DSA-driven
diffusion process and athermal stress. Specifically, the plateau emerges from DSA mechanisms in the presence of atomic
diffusion, whereas in the absence of
diffusion, it is governed by athermal statistical
lattice distortions. This dual mechanism framework provides a comprehensive explanation for the experimentally observed Yield strength behavior in RHEAs at intermediate temperatures.
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All authors Sai Anandhi Seetharaman, Soumyadipta Maiti, Ambesh Gupta, Beena Rai
Statistical Mechanics
Directed percolation transition to active turbulence driven by non-reciprocal forces
Juliane U. Klamser and Ludovic Berthier
We numerically study the collective dynamics of dense particle assemblies driven by non-reciprocal pairwise forces of amplitude $\kappa$. At a critical value $\kappa_{\rm c}$, the system undergoes a dynamical phase transition from an absorbing state ($\kappa < \kappa_{\rm c}$) to a chaotic steady state ($\kappa > \kappa_{\rm c}$). The chaotic phase is marked by nontrivial spatiotemporal velocity correlations and mixing, reminiscent of active
turbulence in self-propelled systems. The sharp onset of chaos shows critical scaling consistent with the universality class of directed percolation. We argue that this transition is generic to a broad class of locally-driven, dense disordered materials.
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Mesoscale and Nanoscale Physics
Dynamic Landau-Lifshitz-Bloch-Slonczewski equations for spintronics
Pascal Thibaudeau, Mouad Fattouhi and Liliana D. Buda-Prejbeanu
The atomistic Landau-Lifshitz-Gilbert equation is challenged when modeling spintronic devices where Joule heating is significant, due to its core assumption of a constant magnetization magnitude. Based on a statistical framework that treats the magnetization magnitude as a dynamic variable coupled to a thermal bath, we derive a dynamic Landau-Lifshitz-Bloch-Slonczewski set of equations for torques, that captures the transient, heating-induced demagnetization that occurs during high-current operation. Integrating these dynamic equations and comparing them to their
stochastic equivalents reveals that both the energy landscape and switching dynamics in high-anisotropy systems are similarly modified. This approach yields accurate and accelerated predictions of critical currents and switching times.
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Disordered Systems and Neural Networks
Learning Linear Regression with Low-Rank Tasks in-Context
Kaito Takanami, Takashi Takahashi and Yoshiyuki Kabashima
In-context learning (ICL) is a key building block of modern large
language models, yet its theoretical mechanisms remain poorly understood. It is particularly mysterious how ICL operates in real-world applications where tasks have a common structure. In this work, we address this problem by analyzing a linear
attention model trained on low-rank regression tasks. Within this setting, we precisely characterize the distribution of predictions and the generalization error in the high-dimensional limit. Moreover, we find that statistical fluctuations in finite pre-training data induce an implicit regularization. Finally, we identify a sharp phase transition of the generalization error governed by task structure. These results provide a framework for understanding how
transformers learn to learn the task structure.
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Soft Condensed Matter
Equilibrium properties of strongly confined fluids
Ana M. Montero
The statistical-mechanical study of the
equilibrium properties of fluids, starting from the knowledge of the interparticle interaction potential, is essential to understand the role that microscopic interaction between individual particles play in the properties of the fluid. The study of these properties from a fundamental point of view is therefore a central goal in condensed matter physics. These properties, however, might vary greatly when a fluid is confined to extremely narrow channels and, therefore, must be examined separately. This thesis investigates fluids in narrow pores, where particles are forced to stay in single-file formation and cannot pass one another. The resulting systems are highly anisotropic: motion is free along the channel axis but strongly restricted transversely. To quantify these effects,
equilibrium properties of the confined fluids are compared with their bulk counterparts, exposing the role of dimensionality. We also develop a novel theoretical framework based on a mapping approach that converts single-file fluids with nearest-neighbor interactions into an equivalent one-dimensional mixture. This exact isomorphism delivers closed expressions for thermodynamic and structural quantities. It allows us to compute the anisotropic pressure tensor and revises definitions of spatial correlations to take into account spatial anisotropy. The theory is applied to hard-core, square-well, square-shoulder, and anisotropic hard-body models, revealing phenomena such as zigzag ordering and structural crossovers of spatial correlations. Analytical predictions are extensively validated against Monte Carlo and molecular dynamic simulations (both original and from the literature), showing excellent agreement across the studied parameter ranges.
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Mesoscale and Nanoscale Physics · Cross-listed from quant-ph
Continuum Model of Isospectrally Patterned Lattices
Fotis K. Diakonos and P. Schmelcher
Isospectrally patterned
lattices (IPL) have recently been shown to exhibit a rich band structure comprising both regimes of localized as well as extended states. The localized states show a single center localization behaviour with a characteristic localization length. We derive a continuum analogue of the IPL which allows us to determine analytically its
eigenvalue spectrum and eigenstates thereby obtaining an expression for the localization length which involves the ratio of the coupling among the
cells of the
lattice and the phase gradient across the
lattice. This continuum model breaks
chiral symmetry but still shows a pairing of partner states with positive and negative energies except for the ground state. We perform a corresponding
symmetry analysis which illuminates the continuum models structure as compared to a corresponding chirally symmetric
Hamiltonian.
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Statistical Mechanics
Identifying non-equilibrium fluctuations in Intracellular Motion Using Recurrent Neural Networks
Tomas Basile, Natascha Leijnse, Malte Slot Lauridsen et al. (+3 more)
Distinguishing active from passive dynamics is a fundamental challenge in understanding the motion of living
cells and other active matter systems. Here, we introduce a framework that combines physical modeling, analytical theory, and machine learning to identify and characterize active fluctuations from trajectory data. We train a long short-term
memory (LSTM) neural network on synthetic trajectories generated from well-defined
stochastic models of active particles, enabling it to classify motion as passive or active and to infer the underlying active process. Applied to experimental trajectories of a tracer in the cytoplasm of a living
cell, the method robustly identifies actively driven motion and selects an Ornstein-Uhlenbeck active noise model as the best description. Crucially, the classifier's performance on simulated data approaches the theoretical optimum that we derive, and it also yields accurate estimates of the active
diffusion coefficient. This integrated approach opens a powerful route to quantify non-
equilibrium fluctuations in complex biological systems from limited data.
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All authors Tomas Basile, Natascha Leijnse, Malte Slot Lauridsen, Younes Farhangi Barooji, Amin Doostmohammadi, Karel Proesmans
Strongly Correlated Electrons · Cross-listed from quant-ph
Lovász Meets Lieb-Schultz-Mattis: Complexity in Approximate Quantum Error Correction
Jinmin Yi, Ruizhi Liu and Zhi Li
Approximate
quantum error correction (AQEC) provides a versatile framework for both
quantum information processing and probing many-body
entanglement. We reveal a fundamental tension between the error-correcting power of an AQEC and the hardness of code state preparation. More precisely, through a novel application of the Lovász local lemma, we establish a fundamental trade-off between local indistinguishability and
circuit complexity, showing that orthogonal short-range entangled states must be distinguishable via a local operator. These results offer a powerful tool for exploring
quantum circuit complexity across diverse settings. As applications, we derive stronger constraints on the complexity of AQEC codes with transversal logical gates and establish strong complexity lower bounds for W state preparation. Our framework also provides a novel perspective for systems with Lieb-Schultz-Mattis type constraints.
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Superconductivity
Systematic evolution of superconducting pairing strength and Seebeck coefficients in correlated infinite-layer La$_{1-x}$Sr$_x$NiO$_2$
Motoki Osada, Shusaku Imajo, Yuji Seki et al. (+6 more)
The recently discovered superconducting infinite-layer nickelates offer a novel platform to explore an exotic pairing mechanism in multi-band systems towards high-temperature superconductivity and associated rich
quantum phases, contrasting with cuprates. Here, we show that infinite-layer (La,Sr)NiO$_2$ exhibits strong-coupling superconductivity, resilient to in-plane
magnetic fields exceeding 47 T at optimal doping - more than twice the Pauli limit for conventional BCS
superconductors. This violation becomes pronounced towards the underdoped regime, implying an intriguing
evolution of pairing glue. The unexpected observation of positive Seebeck coefficients in this regime indicates the presence of nontrivial electron correlations. Furthermore, our comprehensive investigation across the superconducting dome reveals that the
evolution of (thermo)electric normal-state properties - specifically, the sign changes of the
Hall and Seebeck coefficients - coincide with the
evolution of superconducting anisotropy and pairing strength. This demonstrates a definitive link between electron correlations and strong-coupling superconductivity in (La,Sr)NiO$_2$, contributing to a unified framework for understanding unconventional superconductivity.
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All authors Motoki Osada, Shusaku Imajo, Yuji Seki, Kousuke Ishida, Tsutomu Nojima, Kohei Fujiwara, Koichi Kindo, Yusuke Nomura, Atsushi Tsukazaki
Soft Condensed Matter
Twist dominates bending in the liquid crystal organization of bacteriophage DNA
Pei Liu, Tamara Christiani, Zhijie Wang et al. (+4 more)
DNA frequently adopts
liquid-crystalline conformations in both
cells and viruses. The Oseen–Frank framework provides a powerful continuum description of these phases through three elastic
moduli: splay ($K_1$), twist or cholesteric ($K_2$), and bending ($K_3$). While $K_1$ is typically assumed to dominate, the relative magnitude of $K_2$ and $K_3$ in confined DNA remains poorly understood. Here, we combine cryo-electron microscopy,
liquid-
crystal modeling, and
knot theory to quantify this relationship in bacteriophage P4, whose genome is partially organized in a spool-like
liquid-crystalline phase. We first show experimentally that the ordered DNA occupies three concentric layers within the capsid. We then formulate an Oseen–Frank model for this geometry and use it, together with the measured layer radii, to estimate the elastic ratio $\alpha = K_3/K_2$. We find $\alpha \approx 0.0064$, indicating that twist elasticity overwhelmingly dominates bending. To validate this result, we perform Langevin dynamics simulations of DNA trajectories and classify the resulting
knots. The predicted
knot distribution agrees with experimental data from P4, demonstrating consistency between elasticity,
topology, and observed genome organization.
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All authors Pei Liu, Tamara Christiani, Zhijie Wang, Fei Guo, Mariel Vazquez, M. Carme Calderer, Javier Arsuaga