Soft Condensed Matter
Comparative Silane Surface Functionalization Strategies for Enhanced Bloch Surface Wave Biosensing of Anti-SARS-CoV-2 Antibodies
Agostino Occhicone, Alberto Sinibaldi, Paola Di Matteo et al. (+4 more)
Surface functionalization plays a decisive role in the performance of biosensors, as it governs the efficiency and stability of biomolecule immobilization at the sensor interface and, consequently, the overall performance of the biosensing platforms. In this work, we present a comparative study of three organosilane chemistries - APTES, APDMS, and CPTES - applied to a SiO2 terminated 1D photonic
crystal able to sustain Bloch surface waves and designed to operate as optical biosensors in both label free and fluorescence enhanced modes. Each chemistry was evaluated through a standardized label-free protocol based on the interaction between immobilized SARS CoV 2 spike
protein and its corresponding antibodies, enabling quantitative assessment of binding efficiency, nonspecific adsorption, and signal repeatability. CPTES exhibited the most favorable balance between specific signals, reduced variability, and low nonspecific adsorption. The three chemistries were subsequently tested in fluorescence mode for the detection of anti SARS CoV 2 IgG antibodies in human serum, demonstrating the suitability of BSW enhanced fluorescence for rapid serological analysis. Overall, the study identifies CPTES as the most robust and reproducible functionalization strategy among the three investigated for BSW biosensing and highlights the potential of the platform for fast, sensitive detection of clinically relevant antibodies.
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All authors Agostino Occhicone, Alberto Sinibaldi, Paola Di Matteo, Daniele Chiappetta, Riccardo Guadagnoli, Peter Munzert, Francesco Michelotti
Materials Science
The influence of implantation conditions on dopant activation in Al-implanted 4H-SiC: A MD study applying an Al potential fitted to DFT barriers
Sabine Leroch, Robert Stella, Andreas Hössinger et al. (+1 more)
The non-monotonic dependence of Al dopant activation on implantation temperature in 4H-SiC has been experimentally observed, but its atomistic origin remains unclear. We present a molecular dynamics (MD) study of Al implantation at $500$,K and $900$,K over seven doses from $1\times10^{13}$ to $7.5\times10^{14}$,cm$^{-2}$, followed by up to $100$,ns of annealing at $1500$–$2500$,K. Using the Gao-Weber potential combined with a reparameterized Morse potential for Al-SiC interactions fitted to DFT migration and kick-in/out barriers, we show that implantation at both temperatures reduces Frenkel-pair formation and extended amorphous pockets compared with room-temperature implantation. Above the Al solubility limit ($>10^{20}$,cm$^{-3}$), however, annealing reveals a non-monotonic temperature dependence. Samples implanted at $900$,K form larger, kinetically stable interstitial clusters that persist throughout annealing and act as sinks and trapping centers for Al, reducing substitutional incorporation. Although the $500$,K samples initially exhibit lower crystallinity, they contain a significantly larger fraction of substitutional Al after annealing. The simulations identify two regimes: a low-dose regime dominated by isolated point defects and small complexes, and a high-dose regime characterized by defect clustering and planar-defect formation with strong implantation-temperature dependence. These results explain the experimentally observed optimal implantation window between $500$ and $900$,K and suggest that controlled nanoscale amorphization at $500$,K enhances activation through regrowth-assisted incorporation while suppressing extended defects. The simulations also identify a new basal-plane
diffusion path for Al and an activation mechanism involving kick-out of a carbon antisite; both were confirmed by DFT-NEB calculations.
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All authors Sabine Leroch, Robert Stella, Andreas Hössinger, Lado Filipovic
Soft Condensed Matter
Odd pathways speed up self-assembly
Dawid Dopierała, Luca Cocconi, Robert L. Jack et al. (+1 more)
Active self-assembly can bypass
equilibrium bottlenecks through external energy injection. However, generic driving typically distorts target structures and requires sustained energy input even after assembly is complete. Here, we investigate a class of non-reciprocal interactions that accelerates assembly while preserving the
equilibrium Boltzmann distribution. The probability currents induced by these odd interactions reshape fundamental processes, including activated barrier crossing, soft-mode relaxation, and transitions between metastable states. In particular, these currents enhance Arrhenius rates by driving particles across otherwise inaccessible free-energy barriers. We show that this acceleration arises from an effective increase in the mobility of the reaction coordinate, mediated by non-reciprocal coupling between mechanical modes. In turn, we discover a trade-off between kinetic acceleration and power dissipation when active forces are engaged. Our results suggest a route to energy-efficient, high-fidelity self-assembly via active catalysts that transiently accelerate relaxation toward
equilibrium targets and deactivate upon reaching the desired state.
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All authors Dawid Dopierała, Luca Cocconi, Robert L. Jack, Anton Souslov
Materials Science
Accurate Nanoscale Mapping of Electric Fields across Random Grain Boundaries in Polycrystalline Oxides Using Precession-Assisted 4D-STEM
Sangjun Kang, Hyeyoung Cho, Maximilian Töllner et al. (+12 more)
Space charge layers (SCLs) at grain boundaries play a crucial role in modulating local electric fields and influencing the functional properties of materials, such as oxygen vacancy migration and ionic conductivity in
oxide ceramics. However, the direct experimental analysis of such localized electric fields and the corresponding charge distribution remains challenging. Conventional center-of-mass (CoM) analysis in scanning transmission electron microscopy differential phase contrast (STEM-DPC) is strongly affected by orientation-dependent contrast and dynamical scattering. Here, we demonstrate that combining electron beam precession with advanced post-processing, employing iterative edge detection via a Sobel filter and singular value decomposition (SVD), enables reliable and accurate, unbiased diffraction shift measurements with minimal crystallographic artefacts. The new method accurately refines the central disk position in nanobeam electron diffraction (NBED) patterns and thus significantly improves the extraction of the local electric field and corresponding charge distribution. Comparative analysis with conventional CoM methods shows superior accuracy and robustness for random grain boundaries in BaTiO3 and SrTiO3 as exemplary case studies. The experimental work is complemented by atomistic simulations to separate the electric field of the SCL from the mean inner potential difference of the grain boundary and the elemental segregation around the grain boundary. The in-depth analysis shows that our approach enables high-fidelity mapping of electromagnetic fields and their charge distribution in complex polycrystalline specimens, laying the groundwork for improved quantitative analysis using STEM-DPC.
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All authors Sangjun Kang, Hyeyoung Cho, Maximilian Töllner, Anna Rose Nelson, Ziming Ding, Xiaoke Mu, Di Wang, Wolfgang Rheinheimer, Kai Wang, Bai-Xiang Xu, Jakob Konstantin Laux, Mahmoud Serour, Karsten Albe, Andreas Klein, Christian Kübel
Soft Condensed Matter
Surface coating induced lubrication in flowing granular materials
Sayali V. Chaudhary and Ashish V. Orpe
We investigate the flow of spherical, bulk granular particles down an inclined plane mixed with small-sized spherical lubricant particles using discrete element method simulations. Predefined cohesive interaction is implemented between lubricant and bulk particles, enabling the coating of the former over the latter. The overall flow rate exhibits non-monotonic dependence on lubricant content. Initially, it increases with lubricant addition, reaches a maximum at an intermediate lubricant content, and decreases for even higher lubricant content. The increase in the flow rate is attributed to a lower inter-particle friction coefficient between lubricant-coated bulk particles. The decrease in the flow rate at higher lubricant content, on the other hand, is attributed to enhanced densification and increased damping between crowded particles. Both these occurrences are examined using various flow level characteristics. The simulation results are found to be in qualitative agreement with previous experimental results. Overall, the outcome integrates novel computational insights and prior experimental results to enhance the understanding of the powder lubrication phenomena.
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Materials Science
Nature of point defects in bulk hexagonal diamond
Ling Zhu, Xuanxuan Zhang, Guliqinayi Alimu et al. (+3 more)
Hexagonal diamond (HD), an exotic carbon allotrope recently synthesized in bulk form, exhibits superior mechanical properties compared to cubic diamond (CD) and holds promise for advanced industrial and
quantum applications. Using first-principles calcu-lations, we systematically investigate intrinsic defects, extrinsic dopants, and defect complexes in HD. Our study shows that VC dominates intrinsic conductivity, while Ci is unstable. Among extrinsic dopants, boron acts as a benign acceptor enhancing p-type conductivity, whereas nitrogen and phosphorus serve as effective donors for n-type conductivity. Group II and Group IV dopants, however, introduce high formation energies or neutral charge states with limited impact. Furthermore, VC, MgC and XV defect com-plexes display multiple
spin and charge states within the HD band gap, highlighting their potential as color centers for hosting
qubits. These results not only clarify the defect physics of HD but also demonstrate its broader implications for conductivity engineering and
quantum technologies.
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All authors Ling Zhu, Xuanxuan Zhang, Guliqinayi Alimu, Chen-Min Dai, Chunlan Ma, Zenghua Cai
Statistical Mechanics · Cross-listed from quant-ph
No-Go Theorem for Quantum Heat Engines Powered Purely by Quantum Measurements in the Steady Regime
Kenta Koshihara and Kazuya Yuasa
We study the thermodynamics of a
quantum measurement-powered engine that converts energy injected by measurement backaction into work. We consider an engine with a finite-dimensional working substance, driven purely by
quantum measurements, i.e., by bare
quantum measurements, without feedback control or thermal contact in the thermodynamic cycle. On the basis of a Poincaré-like recurrence
theorem for general
quantum channels, we prove a no-go result for work extraction from such an engine in the steady regime. In the steady regime,
quantum measurements become nondisturbing and do not inject energy into the working substance. Consequently, no work can be extracted. This result reveals the necessity of an
entropy-decreasing process, such as feedback control or thermal contact, for work extraction in steady-cycle measurement-powered engines.
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Soft Condensed Matter
Covariant Onsager and Onsager-Machlup principles for active and inertial dynamics
Kento Yasuda, Bin Zheng, Zhongqiang Xiong et al. (+5 more)
The Onsager principle provides a variational route to the phenomenological equations of dissipative dynamics through the minimization of the Rayleighian. We develop a covariant formulation of the Onsager principle for active and inertial systems, ensuring
geometric consistency under coordinate transformations. To further incorporate thermal fluctuations, we formulate the Onsager-Machlup principle for active and inertial systems by considering the Onsager-Machlup functional and the corresponding path probability for
stochastic trajectories. Requiring that the path probability obeys the detailed fluctuation
theorem, we show that the extended Onsager-Machlup theory is consistent with
stochastic thermodynamics. The extended OP and OMP offer a unified and useful variational framework for deriving the dynamical equations of active and inertial systems.
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All authors Kento Yasuda, Bin Zheng, Zhongqiang Xiong, Zhanglin Hou, Kenta Ishimoto, Xinpeng Xu, David Andelman, Shigeyuki Komura
Statistical Mechanics
Spiral, target, stripe, and disordered waves in active six-state Potts models
Hiroshi Noguchi
Wave propagation can be observed in various nonequilibrium systems. In this study, we investigated the properties of several wave modes in active six-state Potts models using Monte Carlo simulations of square and hexagonal
lattices. Disordered and spiral (SP) waves of six states are formed under weak and strong repulsions at nonflip contacts, respectively. The target (TG) and stripe (ST) waves were found to emerge under stronger repulsion. These three wave modes (SP, TG, and ST) can temporally coexist in small systems near the transition points but they do not switch in large systems or far from these transition points. During coarsening from randomly mixed states to ST waves, SP waves appear at an intermediate stage. The SP wave modes of three even- or odd-numbered states (states $s=0,2,4$ or $s=1,3,5$) emerge under two conditions: repulsion at the diagonal contact and attraction at nonflip contacts. Previously thought to be identical for both conditions, the wave types were found to differ, comprising forward and backward waves ($s=1\to 3\to 5\to 1$ or $s=1\to 5\to 3\to 1$), whose domain boundaries move by the two-step and four-step forward flips, respectively. The transition between the waves of the even- and odd-numbered states is first-order for both the forward and backward waves.
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Mesoscale and Nanoscale Physics
Electric-Field Control of Quantum Tunneling Regimes in Focused He-Ion-Beam-Irradiated Oxide Interfaces
Yu Chen, Maria D'Antuono, Robin Hutt et al. (+6 more)
Helium focused ion beam irradiation enables the fabrication of tunnel field-effect transistors based on two-dimensional electron systems (2DESs) at an
oxide interface.High resolution scanning transmission electron microscopy and strain mapping reveal localized
lattice deformation confined to the irradiated regions, which act as nanoscale potential barriers. The barrier profile can be continuously tuned by electrostatic backgating at low temperature without degrading the electronic properties of the 2DES electrodes. Transport measurements demonstrate controlled access to thermionic emission, direct tunneling, and Fowler-Nordheim tunneling within a single device architecture. These results establish He FIB irradiation as a powerful tool for nanoscale functional engineering of complex-
oxide interfaces and provide a platform for exploring gate-tunable
quantum tunneling phenomena.
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All authors Yu Chen, Maria D'Antuono, Robin Hutt, Cesar Magen, Edward Goldobin, Dieter Koelle, Reinhold Kleiner, Marco Salluzzo, Daniela Stornaiuolo
Materials Science
Dynamic Moiré Potentials and Robust Wigner Crystallization in Large-Scale Twisted Transition Metal Dichalcogenides
Yifan Ke, Chuanjing Zeng, Xinming Qin et al. (+3 more)
Understanding the dynamical
evolution of large-scale moiré systems is crucial for connecting theoretical predictions with experimental observations. Here we develop a machine-learning-based workflow, integrating DeePMD and DeepH frameworks with first-principles calculations, to efficiently investigate time-dependent structural and electronic responses in twisted
bilayer transition metal dichalcogenides (TMDs) with experimentally relevant moiré supercells containing over 3000 atoms. Using $\mathrm{WS_2}$ as a representative system, we show that low-temperature
lattice vibrations and relaxation deepen the moiré potential wells, narrow the lowest conduction band, and facilitate the formation of strongly localized electronic states. Based on DFT-derived moiré potentials that incorporate these dynamical effects, density-
matrix-renormalization-group (DMRG) simulations reveal robust Wigner crystallization and a kagomé-patterned three-electron state, consistent with recent experimental observations. Our workflow provides a practical route for exploring large moiré supercells beyond static configurations and offers new insight into the interplay between
lattice dynamics, electronic localization, and emergent correlated states in twisted two-dimensional materials.
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All authors Yifan Ke, Chuanjing Zeng, Xinming Qin, Wei-Lin Tu, Wei Hu, Jinglong Yang
Statistical Mechanics
The quantum harmonic oscillator in a dissipative bath of anyon pairs
Nils-Henrik Meyer, Axel Pelster and Michael Thorwart
We generalize the formalism of open
quantum systems to introduce anyon baths. In particular, we work out a dissipative anyon bath composed of independent pairs of one-dimensional Grundberg-Hansson harmonically bound anyons, which are characterized by one statistical parameter. Using a mapping of these anyons to a bosonic bath with rescaled oscillator frequencies, we show that the original bilinear system-bath coupling assumes a particular non-
polynomial form. To determine the relaxation properties, we use the imaginary-time path integral formalism together with a generalization of Wick's
theorem in the form of a smearing formula. The latter allows to approximately calculate the anyon bath spectral density, which acquires a nontrivial temperature dependence. The corresponding relaxation dynamics of the dissipative harmonic oscillator in an anyon bath is found. Well defined limits are revealed for both low and high temperatures. Anyonic features turn out to be most pronounced in the regime of intermediate temperatures.
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Strongly Correlated Electrons
Bao-Qing Wang, Can Shao, Takami Tohyama et al. (+2 more)
The emergence of the
antiferromagnetic (AFM) Chern
insulator (AFCI) phase in the Kane-Mele-Hubbard (KMH) model with a finite sublattice potential is investigated. The AFCI, characterized by AFM correlations coexisting with quantized
Hall conductance, has long raised the question of whether it can exist in the KMH model that respects time-reversal
symmetry (TRS). Using exact diagonalization, we analyze the excitation gap, anisotropic AFM correlations along the $z$ axis and in the $xy$ plane, and the fidelity susceptibility under twisted boundary conditions, all of which provide consistent evidence for the AFCI phase. In particular, our numerical evaluation on the (
spin) Chern number reveals a breakdown of adiabatic continuity in the twist-angle space, indicating an instability toward TRS breaking driven by Hubbard-induced AFM perturbations. A modified computational scheme is further proposed, which yields a robust quantized Chern number $C=1$ within this phase.
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All authors Bao-Qing Wang, Can Shao, Takami Tohyama, Hong-Gang Luo, Hantao Lu
Superconductivity
Theoretical prediction of strong-coupling superconductivity in a hypothetical NaAlH3 phase at ambient pressure
Izabela A. Wrona, Yinwei Li, Radoslaw Szczesniak et al. (+1 more)
We present a comprehensive first-principles investigation of a hypothetical cubic Pm-3m phase of the ternary hydride NaAlH3, focusing on its
lattice dynamics, electronic structure, and electron-
phonon-mediated superconducting properties at ambient pressure. Using density functional theory and the Migdal-Eliashberg formalism, we find an exceptionally strong electron-
phonon coupling ($\lambda=2.23$), resulting in a superconducting critical temperature of up to 73.7 K for a Coulomb pseudopotential $\mu^* = 0.1$.
Phonon dispersion calculations, complemented by ab initio molecular dynamics simulations, indicate dynamic and thermal stability within the adopted theoretical framework. The electronic structure exhibits a metallic character with substantial contributions from Al- and Na-derived states at the
Fermi level. The resulting superconducting gap ratio ($2\Delta(0)/k_B T_c \approx 4.8$) and specific heat jump ($\Delta C/\gamma T_c \approx 2.2$) significantly exceed BCS weak-coupling predictions, highlighting the strong-coupling nature of superconductivity in this hypothetical phase.
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All authors Izabela A. Wrona, Yinwei Li, Radoslaw Szczesniak, Artur P. Durajski
Statistical Mechanics
A variational formulation of stochastic thermodynamics: Spatially extended systems
Héctor Vaquero del Pino, François Gay-Balmaz, Hiroaki Yoshimura et al. (+1 more)
Stochastic field theories are often constructed phenomenologically, without a systematic assessment of thermodynamic consistency or local detailed balance. This may hinder a physical description of irreversibility at the field-theoretic level beyond the standard statistical formulation of
stochastic thermodynamics. Here, we develop a variational formulation for thermodynamically consistent
stochastic field theories by extending Hamilton's principle of classical field theory. Introducing the second law as an axiom yields a consistent local thermodynamic structure in which novel fluctuationdissipation relations emerge naturally, ensuring local detailed balance. Remarkably, the resulting
entropy production takes the same form as in standard
stochastic thermodynamics, up to a reformulation in an extended phase space incorporating both configurational and thermal variables. This correspondence extends key results, including individual trajectory-level thermodynamics and fluctuation
theorems. The construction is formulated within a unified
geometric framework based on a generalized Lagrange-d'Alembert principle, providing a top-down connection between phenomenological modeling and thermodynamic consistency. Potential applications include thermodynamically consistent modeling of complex fluids, Lagrangian reduction by
symmetry in continuum systems, and structure-preserving numerical schemes for
stochastic partial differential equations.
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All authors Héctor Vaquero del Pino, François Gay-Balmaz, Hiroaki Yoshimura, Lock Yue Chew
Soft Condensed Matter
Active Jurin's law
Birendra Mandal and Joydip Chaudhuri
Capillary rise is one of the classical problems in fluid mechanics and is traditionally described by Jurin's law, which balances capillary suction against hydrostatic pressure. Here we extend this classical result to active fluids, materials that generate internal stresses through microscopic energy consumption. Using the continuum theory of active nematics, we show that activity modifies the normal stress balance at the
liquid-gas interface through an additional active normal stress contribution. This leads to a generalized active Jurin's law, which can be written in dimensionless form as \(H_{\infty} = 1 - \mathrm{Ja}_a \xi_0\), where \(H_{\infty}\) is the dimensionless active Jurin height at
equilibrium, \(\mathrm{Ja}_a\) is an active Jurin number comparing active stress to capillary pressure, and \(\xi_0\) characterizes the
alignment of active constituents at the meniscus. The theory predicts that extensile and contractile active fluids can either enhance or suppress capillary rise depending on the magnitude of activity and the interfacial
alignment state. From this relation we construct a phase diagram in the \((\mathrm{Ja}_a,\xi_0)\) plane that delineates regimes of activity-enhanced rise, activity-suppressed rise, and complete suppression of the classical capillary state. When orientational order depends on confinement and flow, the coupling between activity and capillarity produces nonlinear
equilibrium conditions that may admit multiple steady heights; linear stability analysis reveals that the overdamped dynamics selects a single stable state, whereas the inertial extension allows the possibility of activity-induced bistability. These results show that internally generated stresses fundamentally reshape one of the most classical capillary transport problems.
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Strongly Correlated Electrons
QAssemble: A Pure Python Package for Quantum Many-Body Theory
Seongjun Mo, Dongming Li, Mancheon Han et al. (+5 more)
QAssemble is a pure-Python package for the
quantum many-body problem. It implements various functional approaches, such as tight-binding, Hartree-Fock, and GW approximations within a unified object-oriented architecture. Each physical concept–
crystal structure,
Hamiltonian, Green's function, self-energy, polarizability, screened Coulomb interaction–is represented as a distinct class. The modular design prioritizes code clarity and extensibility, leveraging NumPy, SciPy, and libdlr for numerical operations. Performance-critical kernels, including the polarizability bubble, Dyson equation inversion, and
lattice Fourier transforms, are systematically vectorized and combined with the discrete Lehmann representation to achieve practical efficiency within a pure-Python environment. We validate QAssemble on the electronic structure of
graphene with local and non-local interactions. Furthermore,
benchmarks on a five-orbital extended Hund-Hubbard model demonstrate that this strategy delivers up to a 60x speedup over traditional loop-based Matsubara implementations. QAssemble supports both batch execution for production calculations and interactive workflows for method development.
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All authors Seongjun Mo, Dongming Li, Mancheon Han, Johan Jönsson, Byungkyun Kang, Hoonkyung Lee, Gabriel Kotliar, Sangkook Choi
Strongly Correlated Electrons
Long-lived relaxation channel and exciton-phonon coupling in Ta2NiSe5 via non-degenerate pump-probe spectroscopy
Poulami Ghosh, Anupama Chauhan, Sidhanta Sahu et al. (+3 more)
An excitonic
insulator represents a
quantum phase in which spontaneous condensation of
excitons leads to novel many-body phenomena. Ta$_2$NSi$_5$ (TNSe), a layered narrow-gap
semiconductor, has emerged as a model platform to probe these correlated excitonic phases and their underlying dynamics below 327 K. In this work, we investigate the nonequilibrium dynamics of TNSe using temperature-dependent, non-degenerate optical pump-probe spectroscopy with a 3.14 eV pump and a 1.57 eV probe, extending the accessible pump-probe delay window up to 500 ps. In addition to the well-established sub-picosecond relaxation channel ($\sim$ 0.7- 0.9 ps) associated with carrier cooling and recombination, accompanied by
exciton reformation, we uncover a much slower recovery process with a decay time of $\sim$ 280-600~ps, significantly longer than previously reported. We attribute this unusually prolonged recovery to enhanced scattering between
excitons and nonequilibrium
phonons, which delays the re-establishment of
equilibrium excitonic correlations. On top of this bi-exponential background, we observe two coherent
phonon modes at 1.0 and 2.9 THz with distinctly different coupling behaviors. The 1.0 THz mode exhibits an order-parameter-like temperature dependence, consistent with strong coupling to the excitonic condensate in TNSe. In contrast, the 2.9 THz mode does not exhibit any discernible coupling to the excitonic order parameter, and appears to arise from anharmonic
lattice dynamics associated with the structural phase transition. Together, these results elucidate the hierarchy of relaxation pathways in TNSe and highlight the importance of extending the temporal detection window in pump-probe measurements to fully capture long-lived
exciton-
phonon dynamics.
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All authors Poulami Ghosh, Anupama Chauhan, Sidhanta Sahu, Sk Kalimuddin, Mintu Mondal, N. Kamaraju
Superconductivity
Non-volatile superconducting tunnelling magnetoresistance memory enabled by exchange-field gap engineering
Sonam Bhakat, Pushpak Banerjee, Ahmedullah Aziz et al. (+2 more)
Scalable, low-dissipation
memory operating below 4 K is a critical requirement for superconducting and
quantum computing systems. Existing cryogenic
memory technologies rely on CMOS derivatives or hybrid architectures that incur leakage, refresh overhead or limited compatibility with superconducting logic. Here we demonstrate a superconducting tunnelling magnetoresistance device that functions as a non-volatile cryogenic
memory element across the full superconducting temperature range. By integrating a de Gennes
spin valve with a superconducting tunnel junction in a current perpendicular-to-plane geometry, we realise exchange-field control of the superconducting energy gap. This produces two magnetically switchable gap voltages and robust quasiparticle tunnelling magnetoresistance down to 0.25 K.The device operates at millivolt bias with nanowatt-level read power and zero standby dissipation. Its vertical junction architecture and Nb-based materials platform enable compatibility with superconducting logic and scalable cryogenic
memory arrays.
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All authors Sonam Bhakat, Pushpak Banerjee, Ahmedullah Aziz, Jackson Miller, Avradeep Pal
Strongly Correlated Electrons · Cross-listed from physics.chem-ph
Dynamically Corrected Bethe-Salpeter Equation Solver for Self-consistent $GW$ Reference on the Matsubara Frequency Axis
Ming Wen, Gaurav Harsha and Dominika Zgid
We present a Bethe-Salpeter equation (BSE) solver based on a self-consistent $GW$ reference evaluated on the Matsubara frequency axis, referred to as BSE@sc$GW$. The self-consistent $GW$ starting point provides a robust quasiparticle description and reduces sensitivity to the initial mean-field reference compared to one-shot $GW$-based approaches. We further introduce a dynamical correction to the static Casida formulation via a plasmon-pole model. This scheme incorporates simple dynamical screening effects while retaining the efficiency of an effective
eigenvalue problem. The resulting dynamically corrected BSE@sc$GW$ yields excitation energies in close agreement with high-level wavefunction-based
benchmarks for both singlet and triplet excitations of small molecules. Overall, the accuracy of the dynamic BSE@sc$GW$ approach arises from the combination of a well-converged single-particle reference and the inclusion of frequency-dependent screening effects.
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Statistical Mechanics · Cross-listed from quant-ph
Signature of paraparticles: a minimal Gedankenexperiment
Francesco Toppan
Paraparticles beyond
bosons and
fermions can be exchanged via either the braid group (anyons, existing up to $D=2$ space dimensions) or the permutation group; in the latter case the space dimensions are not limited. Besides being predicted, anyons have been experimentally detected. The situation differs for paraparticles exchanged via the permutation group ("permutation-group parastatistics").The first test to detect their theoretical signature was published in 2021 (for $Z_2\times Z_2$-graded parafermions; it was soon followed by a second paper proving the detectability of $Z_2\times Z_2$-graded parabosons). Later on, two further papers proved theoretical signatures of permutation-group parastatistics. These works demonstrate that, in certain situations, a long-held belief on the "conventionality of parastatistics" argument can be evaded: some measurements of permutation-group paraparticles cannot be recovered from ordinary
bosons/
fermions. The main question now is how to experimentally detect or engineer in the laboratory such paraparticles. For this aim a minimal setup for the theoretical test is here provided: a Gedankenexperiment (a simplified version of the two tests published in 2021) which, essentially, is a flow chart of logical operations. The key point is to present, to experimentalists, the necessary steps to be simulated/realized in the laboratory (possibly, by manipulating qudits). In this minimal setup, the detection/engineering of paraparticles is mapped into a chirality test. The mathematical setting is based on $Z_2\times Z_2$-graded color Lie (super)
algebras and derived mathematical structures.
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Mesoscale and Nanoscale Physics
Microscopic Modeling of Surface Roughness Scattering in Inversion Layers of MOSFETs Based on Ando's Linear Model
Nobuyuki Sano
Surface roughness (SR) scattering in inversion layers of bulk-MOSFETs is studied from the atomistic and
quantum-mechanical viewpoints. Contrary to the usual macroscopic landscape of the roughness deviation, we introduce a
stochastic deviation at each atomic site to take account of the discontinuity of the spatial derivatives of the electrostatic potential and wave-function at the
semiconductor/dielectric interface, leading to an ambiguity in roughness positions. It is shown that SR parameters are consistent with those known from the experiments and, thus, there is no discrepancy problem associated with the roughness parameters in our model. The self-consistent scattering rate is derived under the framework of the Green's functions scheme: We find that the SR scattering rates are intrinsically nonlocal (non-diagonal) with respect to subband indices and greatly deviate from those based on
Fermi's golden rule in the regimes of strong effective fields and/or low electron energies. As a result, the conventional SR model tends to underestimate the surface-roughness-limited mobility.
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Statistical Mechanics
Long-Range Order in Coupled $D$-dimensional Kuramoto Oscillators
Zhongpu Qiu, Tianyi Wu, Linkai Zhang et al. (+4 more)
We show that the long-range order (LRO) strikingly emerges in systems of locally coupled $D$-dimensional vector Kuramoto oscillators on low-dimensional
lattices ($d=1,2$), but only for odd $D$. This parity-dependent effect is traced to two-oscillator dynamics, where odd-$D$ units synchronize for any coupling, while even-$D$ pairs require a finite threshold. This fundamental difference selectively seeds collective order in large-scale systems, a phenomenon demonstrated by our numerical simulations. A renormalization group analysis reveals a RG flow to a weak-coupling fixed point for $d \le 2$. In this limit, odd-$D$ systems effectively map to a
ferromagnetic model, developing an ordered “hemisphere" phase, whereas even-$D$ systems remain disordered. Our findings further reveal orientational LRO emerges in both $d=1$ and $d=2$, but frequency LRO requires $d=2$. We contrast these results with the established behavior of models possessing continuous
symmetry, highlighting how quenched disorder provides a fundamentally new route to order.
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All authors Zhongpu Qiu, Tianyi Wu, Linkai Zhang, Sheng Fang, Jun Meng, Jingfang Fan, Hugues Chaté
Mesoscale and Nanoscale Physics
Harnessing Plasmonic Heating For Switching In Antiferromagnets
H. Y. Yuan, Yizheng Wu and Olena Gomonay
Heat waste is a bottleneck in the development of green information technologies and much effort has been devoted to suppress the heating effect in both electronic and spintronic devices. Here we take an alternative approach and show that controllable heating at the nanoscale can actually benefit information processing. In particular, we study a hybrid nanostructure consisting of a metallic square frame and an
antiferromagnetic (AFM) thin film and show that the plasmonic heating can reversibly switch two perpendicularly-oriented AFM domains without the assistance of
magnetic fields and electric currents. The required switching energy is at the order 1 nJ, three to six orders of magnitude lower than the current-driven AFM switching. The physical mechanism arises from the thermal-induced strain fields inside the frame, which couple to and manipulate the
magnetic orientation via magnetoelastic effect. The strain field direction can be well controlled by selectively exciting the longitudinal and transverse plasmon modes by varying the polarization of the waves, which readily allows for a reversible switching of the AFM vector. Our findings provide tremendous opportunities for optically manipulating the magnetism with ultralow energy consumption and may further promote the interdisciplinary study of photonics, acoustics and spintronics.
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Other Condensed Matter
Extended Haldane Model in The Dice Lattice: Multiple Flat-Band-Induced topological Transitions Revealed
Othmane Benhaida, Lalla Btissam Drissi and El Hassan Saidi
In this study, we examine the introduction of the Haldane model into the dice
lattice by altering the flow between the next-nearest-neighbour sites. This breaks the
lattice's inversion and time-reversal
symmetries. We demonstrate the presence of point-charge particle
symmetries at $\phi^c=\pi/6$ and $5\pi/6$ and derive the analytical expression for quasi-energies. We demonstrate that a gap closure occurs at these critical points, inducing a topological transition. This is confirmed by calculating the Berry
curvature and orbital
magnetic moment. A topological analysis shows that the Chern numbers of the valence band $(\nu=0)$, the flat band $(\nu=1)$ and the conduction band $(\nu=2)$ depend strongly on the relationship between the fluxes $\phi^a $ and $\phi^c$. When $\phi^c = \phi^a$, the Chern numbers are $(C_0, C_1, C_2) = (2, -2, 0)$ in the region $\phi^c \in [0, \pi/6[$, and (0, 2, -2) in the region $\phi^c\in ]5\pi/6, \pi]$. Conversely, when $\phi^c \neq \phi^a$, the topological invariants become $ (C_1, C_2) = (-1, -1)$ for $\phi^c \in [0, \pi/6[$, and $(C_0, C_1, )= (1, 1)$ for $\phi^c\in ]5\pi/6, \pi]$. These variations reflect topological phase transitions at the critical points $\phi^c=\pi/6$ and $5\pi/6$, affecting all of the system's bands. Furthermore, the anomalous
Hall conductivity exhibits a quantized plateau of 2$\sigma_{0}$, as well as an unquantized tilted plateau evolving from 1.50$\sigma_{0}$ to 1.25$\sigma_{0}$ at the same transition points. Controlling the flux allows topological transitions to be engineered and
quantum transport in the dice
lattice to be optimised, offering promising prospects for reconfigurable topological devices with low dissipation and robust
quantum transport.
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