Materials Science
Predicting large-supercell defect formation energies from machine-learning charge density models trained on small supercells
Junjie Zhou, Menglin Huang and Shiyou Chen
First-principles defect calculations are often limited by the cost of the large supercells required to suppress image interactions. Machine-learning interatomic potentials (MLIPs) provide another alternative, but training defect MLIPs typically requires thousands of structures and weeks of data generation. Since charge density is the key to density-functional-theory (DFT), we propose a machine-learning charge density (MLCD) route for predicting defect formation energies with higher data efficiency. We optimize the training set by integrating small supercells of varying sizes for better extrapolation, allocating their proportions based on spatial charge-density analysis. With only 96 supercells containing 16–96 atoms as the
dataset, MLCD accurately predicts the formation energies of four intrinsic defects in 360-atom supercells, with defect-wise mean absolute error below 0.05 eV. In contrast, MLIPs trained on the same
dataset can err by more than 1 eV. These results show that charge-density learning enables more robust cross-size transfer than direct energy-force fitting and that mixed-size data design can substantially reduce the cost of defect prediction.
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High Energy Physics (Phenomenology)
Flavor–Kinetic Entanglement Production from Decay and Scattering at Finite Density
Zekun Li, Jia Liu, Xiao-Ping Wang et al. (+1 more)
We extend the scattering-
entanglement dictionary to finite-density environments by investigating the
flavor–kinetic bipartition of the
Hilbert space. We show that tracing over kinematic degrees of freedom maps the total branch-changing transition probability directly onto the leading
flavor–kinetic linear
entanglement entropy. At finite density, the
vacuum branch-changing probability is replaced by an occupation-weighted collision probability, built from the same directed reaction-density kernel that enters the integrated Boltzmann equation. The resulting observable is the bath-averaged
flavor–kinetic
entanglement entropy of a pair sampled from the medium. As a proof of principle, this framework is applied to an $O(N)$ singlet-scalar extended model to probe thermal phase transitions. In the examples studied, the resulting
entanglement entropy serves as a collision-based phase-transition-type diagnostic, exhibiting a finite discontinuity across a first-order phase transition and a nonanalytic temperature derivative for continuous transitions. These examples suggest a novel way to characterize thermal phase structures, distinct from traditional thermodynamic order parameters.
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All authors Zekun Li, Jia Liu, Xiao-Ping Wang, Jing-Jun Zhang
Strongly Correlated Electrons
Metallic Gross-Neveu criticality and superconductivity on the $\mathrm{SO}(3)$ SLAC fermion
Feng-Yu Zhang, Yin-Kai Yu, Zi-Xiang Li et al. (+1 more)
The realization of Dirac criticality beyond the conventional Gross-Neveu-Yukawa (GNY) paradigm has become a major frontier in condensed matter physics. In this work, we introduce an $\mathrm{SO}(3)$-symmetric
bilayer SLAC
fermion model with tunable inter-layer interactions that exhibits a rich
quantum phase diagram. As the interaction strength increases, the system undergoes two distinct phase transitions. The primary transition is a continuous boundary separating a Dirac semimetal (DSM) from an $\mathrm{SO}(3)$-broken ordered phase. Crucially, this transition evades the standard GNY universality class because the emergent order only gaps out a subset of the itinerant
fermions. Using large-scale
quantum Monte Carlo (QMC) simulations, we establish that this transition belongs to the Gross-Neveu-$\mathrm{SO}(3)$ universality class with $N=6$ irreducible Dirac cones and precisely extract the corresponding critical exponents. At stronger couplings, a second transition drives the system into an inter-layer $\mathrm{SO}(3)$-symmetric superconducting (SC) state. We provide strong numerical evidence that this transition is first-order. Our study provides new insights into the exploration of Dirac criticality beyond the standard GNY universality class, and also offers a distinct platform for investigating $\mathrm{SO}(3)$-symmetric superconductivity.
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All authors Feng-Yu Zhang, Yin-Kai Yu, Zi-Xiang Li, Shuai Yin
Quantum Physics
Near-Optimal Gap Amplification for Nonnegative Unentangled Quantum Proofs
Masayuki Miyamoto
We study gap amplification of the class $\mathsf{QMA}^{+}(2)$ characterized by unentangled
quantum proofs whose amplitudes are nonnegative in the computational basis. This class was recently introduced by Jeronimo and Wu (STOC 2023), and its behavior depends sharply on the completeness-soundness gap: although it captures the power of $\mathsf{NEXP}$ for some small constant gap, it is equal to $\mathsf{QMA}(2)$ for larger constant gap. This is in stark contrast to $\mathsf{QMA}(2)$ where strong gap amplification is known due to the product test by Harrow and Montanaro (FOCS 2010, JACM 2013). In this paper, we prove for every completeness $c$ and soundness $s$ with $c-s=1/\mathrm{poly}(n)$, \[ \mathsf{NEXP} = \mathsf{QMA}^{+}(2,c,s) = \mathsf{QMA}^{+}\left(2,1-\frac1{\mathrm{poly}(n)},\frac14+\frac1{\mathrm{poly}(n)}\right). \] Our result gives a clean complexity phase transition for $\mathsf{QMA}^{+}(2)$ since we have \[ \mathsf{QMA}^{\mathbb R}(2) = \mathsf{QMA}^{+}\left(2,1-\frac1{\mathrm{poly}(n)},\frac14-\frac1{\mathrm{poly}(n)}\right), \] where $\mathsf{QMA}^{\mathbb R}(2)$ denotes $\mathsf{QMA}(2)$ with witnesses restricted to real amplitudes. Our amplification is thus optimal in the sense that a slight improvement of our soundness would have the collapse \[ \mathsf{QMA}^{\mathbb R}(2)=\mathsf{NEXP}. \] Our proof combines symmetric-subspace projections with the relation $\mathsf{QMA}^{+}(1)=\mathsf{NEXP}$ of Bassirian, Fefferman, and Marwaha (ITCS 2024). The main technical ingredient is a dimension-independent de Finetti
theorem in
Hilbert-Schmidt norm that applies when the number of registers under consideration grows logarithmically.
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General Relativity and Quantum Cosmology
Conformal-Mapping Method for Horizon Multipoles in Numerical Relativity: Implementation, Kerr Validation, and Applications Beyond Axisymmetry
Yeong-Bok Bae, Young-Hwan Hyun and Gungwon Kang
We present a numerical method that constructs geometrically defined coordinates on black-hole horizons, from which the multipole moments are computed without assuming axisymmetry. This method, which we denote the conformal-mapping method (CMM), provides a numerical realization of the conformal construction proposed by Ashtekar et al. in 2022, combining discrete
Ricci flow, spectral
embedding onto the unit sphere, and Möbius gauge fixing by the vanishing-area-dipole condition. We first test the CMM against analytic Kerr
benchmarks, and then apply it to an equal-mass, non-spinning binary black-hole merger. We also compare it with an approximate-
symmetry-based method. The CMM allows the multipole moments to be expressed in a fixed reference frame, whereas the
symmetry-adapted frame can reorient abruptly when the preferred approximate axis changes. In a frame aligned with the orbital angular momentum, the amplitude of the quadrupole mode grows during inspiral and decays after merger, displaying a qualitative ringdown behavior. These results show that the CMM is a useful tool for studying horizon geometry in dynamical situations where no stable
symmetry axis is available.
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Statistical Mechanics
Turning angle analysis reveals hidden anisotropies in intracellular transport
Michał Balcerek, Adrian Pacheco-Pozo, Agnieszka Wyłomańska et al. (+1 more)
Molecular motion within living
cells provides a window into the physical principles underlying intracellular organization and transport. Yet a fundamental limitation remains: measured trajectories are often short, noisy, and randomly oriented, rendering spatial anisotropies inaccessible to conventional analyses. We show that turning-angle statistics provide a robust approach for uncovering anisotropies in anomalous
diffusion. Using a two-dimensional anisotropic fractional Brownian motion model with random orientations, we show theoretically and through simulations that turning-angle distributions preserve signatures of anisotropy. We apply this approach to single-particle tracking data, including
quantum dots in the cytoplasm of HeLa
cells and membrane
proteins in hippocampal
neurons. Turning angles reveal hidden anisotropies in the motion of
quantum dots and Kv1.4 channels, and in specific dynamical states of glycoprotein CD4. These results establish turning-angle analysis as a powerful strategy for detecting organization in complex environments and reveal that anisotropic anomalous
diffusion is an {often} overlooked feature of intracellular dynamics.
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All authors Michał Balcerek, Adrian Pacheco-Pozo, Agnieszka Wyłomańska, Diego Krapf
Instrumentation and Detectors
A High Gain Preamplifier Board for Low Charge Semiconductor Detectors
De Zhang, Kuo Ma, Juzheng Zhang et al. (+3 more)
We present a high-gain, low-noise preamplifier board designed for reading out low-charge
semiconductor detectors–specifically Low-Gain Avalanche Detectors (LGADs) and three-dimensional (3D) silicon sensors–in high-energy physics applications. The
circuit employs a three-stage architecture featuring a discrete SiGe:C bipolar junction transistor (BJT)-based transimpedance amplifier (TIA) front-end followed by two resistive feedback amplification stages using LTC6431 chips. This configuration achieves a charge gain of 115.27 mV ns/fC with excellent linearity over an input range of 0.5 fC to 25 fC and a wide bandwidth spanning from 34.0 MHz to 594.3 MHz. Experimental evaluations coupled with LGAD detectors demonstrate a time resolution of 36.41 ps and an equivalent noise charge (ENC) of 0.18 fC at 20 {\deg}C. Furthermore, tests with conventional PIN sensors without a gain layer yield a timing resolution of 76.10 ps with an ENC of 0.10 fC, and tests with the 3D silicon detector yield 39.40 ps with an ENC of 0.09 fC, all measured under the same thermal condition. All configurations confirm the board's capability in low-signal regimes, significantly outperforming previous reference designs. A six-channel variant of the board has also been developed to support position-sensitive measurements. These findings demonstrate the board's suitability for laboratory-based 4D tracking detector characterisation, while simultaneously providing the groundwork for dedicated ASIC development.
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All authors De Zhang, Kuo Ma, Juzheng Zhang, Jiajin Ge, Yanwen Liu, Hao Liang
Astrophysics of Galaxies
A Two-level Radial-velocity Zero-point Calibration for LAMOST MRS with Gaia and APOGEE and a Value-added RV Catalogue
Jinming Zhang and Haibo Yuan
The LAMOST Medium-Resolution Survey (MRS) provides a large
stellar spectroscopic data set for
Galactic kinematics and time-domain radial-velocity (RV) studies. However, the multi-spectrograph, multi-exposure, multi-fiber observing strategy can imprint RV zero-point (RVZP) systematics that vary across instrumental and temporal hierarchies. We construct a two-level empirical RVZP correction to LAMOST DR12 MRS using
Gaia DR3 magnitude-colour-corrected RVs and APOGEE DR17 RVs as external references: a spectrograph-exposure correction in (lmjm, planid, spid) units, followed by a fiber-time correction in (spid, fiberid, time_tag) units. Within each unit, RVZPs are estimated from
Gaia and APOGEE residuals using a weighted-median
estimator, and are subtracted from the pipeline RVs to obtain corrected velocities. For high-S/N spectra, the scatter relative to APOGEE DR17 decreases from ~1.1 km/s to ~0.52 km/s after the full two-level correction, implying a ~2x improvement in RV precision. We release a value-added catalogue of two-level-corrected RVs for 11,129,477 blue-arm spectra, including 8,158,271 single-exposure spectra and 2,971,206 coadded spectra, enabling consistent RV analyses across exposures, spectrographs, fibers, and time.
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Plasma Physics
Simulations of self-accelerating electron phase space holes in an applied electric field
Ran Guo
The self-acceleration of electron phase space holes in an applied electric field is investigated via one-dimensional electrostatic Vlasov simulations. The electron holes (EHs) are initialized in a self-consistent manner with immobile ions, and the ion response is enabled at the beginning of simulations. A
benchmark simulation is conducted to confirm the EH self-acceleration in the absence of the external electric field. Then, we investigate the EH behaviors by applying the uniform and sinusoidal electric fields, respectively. The effects of different strengths and durations of these external electric fields are studied. It is found that the uniform electric field applied in the direction of the self-acceleration can delay the onset of this process and change the final speed of EHs. The applied sinusoidal electric field can fix the EHs at their initial positions and suppress the self-acceleration if the electric field amplitude and duration are appropriate. In addition, it is observed that these external electric fields can induce the splitting of EHs and the generation of secondary EHs. The physical mechanisms of these phenomena are discussed in detail.
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Fluid Dynamics
Splashing velocity of a viscous liquid squeezed between two parallel disks
Navin Kumar Chandra, Pierre Perrier and David Brutin
Squeezing of a
liquid film between two approaching solid surfaces can generate a high-speed peripheral splash. Despite extensive studies on squeeze-film hydrodynamics, quantitative prediction of the splash velocity remains unresolved, with existing theory significantly overestimating experiments. Here, we present a theoretical framework to predict the ejection velocity of viscous
liquid squeezed between two parallel circular disks. We show that discrepancy of theory from experiments arise due to incomplete treatment of
liquid inertia and from using peak ejection velocity to represent splash velocity. By accounting for both local and convective inertia, and introducing a momentum-averaged ejection velocity, we obtain good agreement with experiments over a wide range of parameters.
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High Energy Physics (Phenomenology)
Strong decays of the possible $D^{*}K$ and $\bar{D}^{*}K$ molecules
Zi-Li Yue, Dian-Yong Chen and Elena Santopinto
Inspired by the rich spectrum of structures near the $D^{(*)}K^{(*)}/\bar{D}^{(*)}K^{(*)}$ thresholds, we postulate the existence of $S$-wave $D^{*}K$ and $\bar{D}^{*}K$ molecules, denoted as $T_{c\bar{s}1}^{f}(2460)$ with $I=0$ (corresponding to $D_{s1}(2460)$), $T_{c\bar{s}1}^{a}(2470)$ with $I=1$, $T_{\bar{c}\bar{s}1}^{f}(2460)$ with $I=0$, and $T_{\bar{c}\bar{s}1}^{a}(2470)$ with $I=1$, respectively. Using an effective Lagrangian approach, we investigate the strong decays of these molecular states. Our estimates indicate that the width of $T_{c\bar{s}1}^{a}(2470)$ is roughly three orders of magnitude larger than that of $T_{c\bar{s}1}^{f}(2460)$, while the widths of $T_{\bar{c}\bar{s}1}^{a/f}(2470)$ are of the same orders as that of $T_{c\bar{s}1}^{f}(2460)$. The present study may provide valuable clues for the experimental search for these molecular candidates.
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General Relativity and Quantum Cosmology
Gravitational radiation from binary systems with time varying masses
Teodora M. Matei, Cristian A. Croitoru and Tiberiu Harko
We consider the properties of the gravitational radiation emitted by massive
stars in binary systems with time varying mass, orbiting around each other in Keplerian orbits under the influence of the gravitational force. When this effect is combined to the quadrupole expression of the gravitational radiation, some supplementary terms in the standard formulae describing radiative effects do appear. By using the generalized quadrupole formalism, with time dependent masses, we obtain the expressions describing the time variation of the angular momentum, semimajor axis, eccentricity and periastron shift of the binary system. As a simple application of the developed formalism we consider in detail two cases of the mass variation, by assuming a linear and an exponential time dependence, respectively. The gravitational radiation characteristics corresponding to these models are fully investigated numerically with the help of a dedicated software package \href{https://github.com/croi900/GRAV-T}{GRAV-T}, specifically developed for the study of the gravitational radiation of the mass varying systems. The impact of the gravitational wave emission on the merger of two magnetars losing mass due to
neutrino heated winds is also investigated in detail. The obtained results could be important for the understanding of general relativistic effects in the case of the variation of the gravitational mass with time, which sensitively influences the properties of the gravitational radiation emission.
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Soft Condensed Matter
Reactive polar mesogenic self-assembly approach enables domain-programmable polymer ferroelectrics
Fan Ye, Minghui Deng, Yuyang Zheng et al. (+13 more)
Ferroelectric
polymers combine switchable polarization with the processability of soft materials, but their development has been dominated by poly(vinylidene fluoride) and related fluoropolymers, whose crystalline polar phases restrict mechanical compliance and domain design with spatial precision. Here we establish a generic design principle for creating intrinsically flexible ferroelectric
liquid-
crystal polymers through reactive polar mesogenic self-assembly. The approach creates polyfluoroalkyl-free
polymer films in which robust ferroelectric order arises from
liquid-crystalline molecular organization rather than crystalline phase formation. By transferring ferroelectric order from fluid mesogenic states into
polymer networks, the resulting materials combine mechanical adaptability with programmable polar architectures. Especially, the photoalignment technology enables these polar states to be organized into pixelated domain architectures. This work establishes a design space towards soft ferroelectric
polymers that integrate molecularly programmed polar order, mechanical tunability and environmentally conscious chemistry, expanding the design space of adaptive materials for flexible electronics, wearable systems and soft robotics.
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All authors Fan Ye, Minghui Deng, Yuyang Zheng, Xiujuan Liu, Xiuhu Zhao, Haowei Jiang, Yanyun Hou, Bingyu Zou, Neng-Ang Peng, Shuo Zhao, Kutay Sağd{\i}ç, Danqing Liu, Yang Shen, Yan-Qing Lu, Satoshi Aya, Mingjun Huang
Quantum Physics
Stable three-dimensional solitons in spin-orbit-coupled atomic-molecular condensates
Chao Kong, Jinqing Li, Guihua Chen et al. (+5 more)
We elaborate a mechanism for the creation of stable three-dimensional (3D)
solitons in
spin-orbit-coupled (SOC) atomic-molecular Bose-Einstein condensate, modeled by the mean-field equations with the quadratic three-wave interaction, characterized by mismatch $\alpha $. The planar (effectively two-dimensional) SOC is applied to the
soliton's atomic component, structuring it as a mixed mode (MM) or semi-
vortex (SV). The molecular component of the SV
soliton is shaped as a 3D
vortex, while the molecular component in the MM
soliton is an MM too. The
solitons exist up to a critical value of $\alpha $. The system demonstrates a relatively large norm share of the
vortex components, exceeding $50\%$ of the total norm, which is an essential feature of SOC-supported
solitons. This is scheme for realizing stable
vortex solitons in free space with the quadratic nonlinearity.
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All authors Chao Kong, Jinqing Li, Guihua Chen, Guilong Li, Zhaopin Chen, Haiming Deng, Boris A. Malomed, Yongyao Li
Quantum Physics
Quantum Chinese Remainder Clock
Ivri Nagar, Alioscia Hamma, Mikel Palmero et al. (+3 more)
The Chinese remainder
theorem is used in metrology for extending the range of
quantum clocks/radar/interferometry, where the phase of a signal is known relative to a set of oscillators with different periods. This paper investigates the performance of a
quantum-mechanical Chinese remainder clock, consisting of atoms/oscillators with pairwise coprime periods. We provide the optimal initial state and the optimal Heisenberg-limited
quantum measurements for measuring time up to the product of the periods. We introduce a novel fault-tolerant post-processing protocol that allows reconstruction of the correct time even in the presence of errors in the remainders.
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All authors Ivri Nagar, Alioscia Hamma, Mikel Palmero, Matthew Radzihovsky, Shouzhuo Yang, Seth Lloyd
General Relativity and Quantum Cosmology
Schwarzschild perturbations in Lorenz gauge via elliptic differential equations
Thomas Osburn, Barry Wardell and Erin Battaglia
Accurate predictions of gravitational wave signals from asymmetric compact binaries are accessible through black hole perturbation theory and self-force calculations. Faithful waveform models will require contributions from first- and second-order terms in the small mass-ratio expansion. The problem of second-order Kerr perturbations is exacerbated by non-separability of the metric perturbation equations and non-linear mode coupling, which motivates this $m$-mode approach. This work moves towards the eventual goal of second-order Kerr perturbations by calculating first-order Schwarzschild metric perturbations via $m$-modes in the frequency domain for the first time. We solve the Lorenz gauge field equations as a system of coupled
elliptic partial differential equations that govern each $m$-mode. Our Mathematica code implements a second-order finite difference representation of the field equations, which we solve as a sparse linear
algebra problem. Regularization near the small body is achieved through the effective source method, and our presentation introduces a new puncture expansion of the singular field for a point mass in Kerr spacetime. Issues related to problematic near-horizon behavior are explored and then mitigated by applying sophisticated near-horizon boundary conditions. Our results illustrate the features of each component and $m$-mode of the metric perturbation, and we are able to calculate gravitational wave energy fluxes with sufficient accuracy to enable future second-order self-force calculations.
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Nuclear Theory
On three-cluster resonance structure of hypernuclei $_{\Lambda}^{7}$He, $_{\Lambda}^{7}$Li and $_{\Lambda}^{7}$Be
N. K. Kalzhigitov, S. Amangeldinova, V. O. Kurmangaliyeva et al. (+1 more)
The bound and resonance states of hypernuclei $_{\Lambda}^{7}$He, $_{\Lambda}^{7}$Li and $_{\Lambda}^{7}$Be are studied within a three-cluster model. Within this model, hypernuclei $_{\Lambda}^{7}$He, $_{\Lambda}^{7}$Li and $_{\Lambda }^{7}$Be are considered as three-cluster systems $^{4}$He+$^2n$+$\Lambda$, $^{4}$He+$d$+$\Lambda$, $^{4}$He+$^2p$+$\Lambda$, respectively. Special
attention is paid to determining resonance states in the three-cluster continuum of these hypernuclei and to study their nature. One semi-realistic nucleon-nucleon potential is employed to determine the internal structure of the clusters $^{4}$He, $^2n$, $d$ and $^2p$, and their interaction. Three versions of the nucleon-hyperon potential, known as the YNG potential, are employed to determine the interaction of the listed clusters with the lambda hyperon. A set of very narrow and fairly wide resonance states is found in the three-cluster continuum of $_{\Lambda}^{7}$He, $_{\Lambda}^{7}$Li and $_{\Lambda}^{7}$Be. The narrowest resonance states were detected in $_{\Lambda}^{7}$He and $_{\Lambda}^{7}$Li and their total width does not exceed 10 keV. The dominant decay channels of these resonance states are revealed.
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All authors N. K. Kalzhigitov, S. Amangeldinova, V. O. Kurmangaliyeva, V. S. Vasilevsky
Mesoscale and Nanoscale Physics
All-electrical Coherent Control of a Single Rare-earth Spin Qubit
Yaowu Liu, Dasom Choi, Stefano Reale et al. (+8 more)
Electrical control of single
spin qubits is a major frontier for nanoscale, high-speed, and scalable
quantum devices. Yet, extending it to highly shielded rare-earth 4f electrons remains an experimental challenge across solid-state platforms. Here we demonstrate all-electrical coherent control of a single Er electron
spin, which is exchange-coupled to a nearby Ti atom. Scanning tunneling microscopy-based electron
spin resonance with three-dimensional
magnetic-field control enables comprehensive mapping of the resonance and Rabi frequencies, revealing pronounced anisotropies in both the Er g-tensor and the Er-Ti exchange interaction. The electrical modulation of the anisotropic Er-Ti coupling results in an efficient drive of the Er
spin, allowing us to achieve near-gigahertz Rabi frequencies - a ten-fold improvement over the present record for rare-earth
spin qubits. By establishing anisotropic exchange as a general resource for electrically accessing shielded rare-earth
spins, our results open a new route to ultrafast and local control of rare-earth
spins in solid-state
quantum devices.
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All authors Yaowu Liu, Dasom Choi, Stefano Reale, Jeongmin Oh, Seorhin Choi, Lei Fang, We-hyo Soe, Arzhang Ardavan, Andreas J. Heinrich, Soo-hyon Phark, Fabio Donati
Instrumentation and Methods for Astrophysics
Spec-S5: A Next-Generation All-Sky Spectroscopic Facility Enabling Large-Scale Surveys for Cosmology and Astrophysics
Claire Poppett, David J. Schlegel, Arjun Dey et al. (+8 more)
The Stage-5 Spectroscopic Experiment (Spec-S5) is a next-generation, all-sky spectroscopic facility designed to address fundamental questions in cosmology and astrophysics. Building on the legacy of the Dark Energy Spectroscopic Instrument (DESI), Spec-S5 will upgrade two existing 4-m
telescopes into 6-m, wide-field observatories, each equipped with a highly multiplexed spectrograph capable of measuring 13,000 spectra simultaneously. This overview paper summarizes the science motivation, system architecture, and integration strategy of the project. Spec-S5 will deliver a more than tenfold increase in spectroscopic capability, enabling transformative surveys in the post-Rubin, post-DESI era and advancing our understanding of dark matter, dark energy, and
cosmic structure formation.
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All authors Claire Poppett, David J. Schlegel, Arjun Dey, Klaus Honscheid, Paul Martini, Alex Drlica-Wagner, Pat Jelinsky, Chang-Jin Oh, Konstantina Boutsia, Joseph H. Silber, Nicholas R. Wenner
High Energy Physics (Theory)
The gravity side of the $p$-adic AdS$_2$/CFT$_1$
Feng Qu
By means of a higher-dimensional
embedding approach, together with the study of distance, measure, and
curvature, we construct a gravitational theory on the two-dimensional space over $p$-adic numbers. Before constructing this gravitational theory, we provide supplementary calculations based on existing literature and justify the validity of the gravitational theory by comparison with the real-number case, for instance, the
curvatures of de Sitter(dS), anti-de Sitter(AdS), and Euclidean space should be positive, negative, and zero, respectively. Finally, as an example on the
gravity side of the $p$-adic AdS$_2$/CFT$_1$, we present the action for a scalar field coupled to
gravity.
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Quantum Gases
Quantum tribology: acceleration-induced Stokes friction and Magnus force in correlated Bose fluids
V. M. Kovalev, A. N. Osipov, O. V. Kibis et al. (+1 more)
The Landau criterion, a cornerstone of
quantum fluid dynamics, dictates that dissipation is forbidden for uniform motion below a critical velocity. Yet, the fundamental question of how acceleration reshapes the principles of
quantum friction has remained open since Landau and Pitaevskii's seminal works. Here, we establish a theoretical framework for the
quantum tribology of non-inertial motion, describing a probe particle undergoing composite translation and rotation within a weakly interacting Bose condensate. Using the nonlinear Gross-Pitaevskii equation, we show that centripetal acceleration fundamentally modifies the energy-momentum constraints on elementary excitations. This leads to a finite drag force in the subsonic regime of the probe particle motion, and a characteristic
quantum stick-slip behaviour in the deeply supersonic regime – a direct generalization of the classical Landau-Pitaevskii picture. Beyond this dissipative response, we uncover a fundamentally distinct mechanism: the nonlinearity of the
quantum fluid, combined with the broken
symmetry of the trajectory, gives rise to a non-dissipative anomalous transverse force. This
quantum Magnus-like response, emerging from the second-order density perturbation, performs no work and is rooted in the
geometric asymmetry of the dynamically induced flow. Our findings lay the foundation for a universal program in
quantum tribology of accelerated motion, establishing a direct and experimentally testable connection among non-inertial dynamics, nonlinear response, and topological
symmetry breaking across platforms ranging from ultracold atoms and
exciton-polariton condensates to cosmological analog systems.
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All authors V. M. Kovalev, A. N. Osipov, O. V. Kibis, I. G. Savenko
General Relativity and Quantum Cosmology
Mapping Schwarzschild Spacetime: From Kruskal to Diamond and Golden Representations
Edgar Alejandro León
We present several representations of the Schwarzschild spacetime. Some of these are classical, such as the
embedding, Tortoise, and Kruskal representations. The latter two motivate the introduction of pulsating coordinates (or the Diamond representation), a compact approach recently proposed for spherically symmetric static metrics. We then introduce the Golden representation for the Schwarzschild spacetime, where what we call the Fibonacci metric, and the golden ratio, become ubiquitous. We conclude by offering some visual and physical interpretations of this approach.
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High Energy Physics (Theory)
Four-Fermion Condensates in Curved Spacetimes: A Functional Approach
Stephon Alexander, Heliudson Bernardo and Jiatong Yan
Four-
fermion interactions appear in effective descriptions of particle physics, many-body systems, and gravitational theories with
fermions. Although the same local operator may enter perturbative scattering, a
vacuum Nambu-Jona-Lasinio (NJL) instability, or finite-density Bardeen-Cooper-Schrieffer (BCS) pairing, these regimes are distinguished by their interaction channels, quadratic kernels, and
quantum states. We give a pedagogical functional account of these distinctions and compute the local one-loop contribution of a scalar-channel NJL mean field to the energy-momentum tensor in curved spacetime. We first display the state data in the in-out functional and construct the closed-time-path functional required for an in-in expectation value. For the NJL saddle, a Hubbard-Stratonovich field shifts the
fermion mass, and the parity-even Dirac determinant generates local volume,
curvature, and
curvature-squared operators. We find the covariant
quantum effective action before specializing to a spatially flat FLRW background and derive the corresponding energy density and pressure. The constant-condensate limit agrees with the direct flat-space mean-field calculation. We also explain which additional state and channel data are required for finite-density BCS pairing and comment on renormalization conditions in curved spacetimes.
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Materials Science
Gate-tunable electronic properties of epitaxial Bi (111) films using a printable hexagonal boron nitride ionogel
Jagannath Jena, Heather E. Kurtz, Siddhesh Ambhire et al. (+9 more)
Achieving effective electrostatic control of carrier transport in semimetals remains challenging due to strong screening and multiband effects. We report efficient low voltage top gated control of electronic transport in epitaxial Bi (111) thin films grown on GaAs (111) substrates using a printable hexagonal boron nitride ionogel. Magnetotransport measurements reveal pronounced nonlinear
Hall conductivities arising from multiband electron and hole contributions. Remarkably, the application of a small gate voltage (less than 0.4 V in magnitude) leads to a systematic
evolution of the low field
Hall conductivity slope and the electron-hole compensation point. The response to gate voltage depends upon thickness and temperature. The observed behavior cannot be explained by a conventional
Fermi level shift with rigid bands and instead indicates a non rigid band response associated with multiband effects and a gat tunable Rashba
spin orbit coupling. Our results establish printable ionogel gating as a powerful approach to tune multiband transport in topological semimetals.
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All authors Jagannath Jena, Heather E. Kurtz, Siddhesh Ambhire, Justin S. Wood, Fateme Mahdikhany, Junyi Yang, Eugene Ark, Vinod K. Sangwan, J. Samuel Jiang, Steven S.-L. Zhang, Mark C. Hersam, Anand Bhattacharya
Quantum Physics
Breaking the Curse of Dimensionality in Quantum PDE Solvers via Gevrey Regularity
Pooya Ronagh, Mariia Sobchuk, Xiaoran Li et al. (+2 more)
We connect different degrees of smoothness of real-valued periodic functions to the number of
qubits required for their high-precision
Fourier-basis amplitude encodings. Our central observation is that the Gevrey hierarchy, which stratifies the space between smooth and analytic functions, provides a natural class for high-precision
quantum algorithms. We use Gevrey regularity to analyze a
quantum algorithm for solving general linear partial differential equations (PDEs) with periodic boundary conditions. We then extend the solver to PDEs with Dirichlet boundary conditions using thin Gevrey collars and a regularized inverse. Our resource bounds specify precision-dependent
Fourier cutoffs and account for restricted discrete stability, elementary gate costs, and restriction to the Dirichlet domain. Finally, we apply our approach to isotropic and anisotropic Poisson equations with periodic and Dirichlet boundary conditions.
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All authors Pooya Ronagh, Mariia Sobchuk, Xiaoran Li, Grecia Castelazo, Ala Shayeghi
Materials Science
Metastability limit of pristine 2D noble metals with high-energy facet: dominance of the Bell-Evans-Polanyi principle
Xiaoliang Zhong
Using density functional theory, we predict that ultrathin (110) sheets of Rh, Pd, Ag, and Ir tend to transform into their (100) counterparts via
lattice contraction. An approximately linear relationship between the transformation barrier and the energy difference between (110) and (100) sheets is revealed, demonstrating that the Bell-Evans-Polanyi (BEP) principle dominates. Furthermore, the critical thicknesses for these metals are also described by the BEP principle: below these thicknesses, the (110) sheets are no longer metastable and undergo spontaneous structural transformation.
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Quantum Physics
Biorthogonal-only Floquet Dynamical Quantum Phase Transitions
Jiangrong Wen, Qidong Yuan, Zi-Xiang Hu et al. (+1 more)
Non-Hermitian dynamical
quantum phase transitions (DQPTs) are intrinsically sensitive to the choice of inner product under nonunitary time
evolution. Although the biorthogonal formulation based on associated states provides a normalized Loschmidt echo with a probabilistic interpretation, previous studies have found biorthogonal and self-normal DQPTs to occur in the same parameter regimes, suggesting that the two forms of dynamical criticality are concomitant. Here we demonstrate that this is not the case. In an exactly solvable periodically driven non-Hermitian Su-Schrieffer-Heeger chain, we uncover a finite biorthogonal-only Floquet DQPT regime, where the biorthogonal Loschmidt rate becomes nonanalytic while the self-normal Loschmidt rate remains smooth. The critical conditions are obtained analytically, showing that the onset of biorthogonal Floquet DQPTs is locked to the exceptional lines of the effective Floquet
Hamiltonian, whereas self-normal criticality has no corresponding spectral boundary. Moreover, for each critical momentum, the biorthogonal DQPT exhibits a pair of critical times within every driving period, whereas the self-normal DQPT exhibits only one. Our results establish a fundamental distinction between biorthogonal and self-normal DQPTs, thereby opening a route toward new nonequilibrium
quantum phenomena in non-Hermitian systems.
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All authors Jiangrong Wen, Qidong Yuan, Zi-Xiang Hu, Jian-Jun Dong
Mathematical Physics
Analytic Integration of the Lambert W Cosmic Fluid Model H(z) Formula
Ken Roberts, Francisco Javier Garcia-Sánchez, Subhajit Saha et al. (+1 more)
The Lambert $W$ (LW) model for the
cosmic fluid equation of state was proposed by S. Saha and K. Bamba in 2019-2020. A recent (early 2026) paper by Dubey, et al, carries out a new fit of the LW model to observational data, in order to estimate the model's parameters. That paper exhibits a formula for the logarithm of the relative Hubble factor at
redshift $z$, $\ln(H(z)/H_0)$, which is based upon a numerical integration. That integral can be evaluated analytically, and we present the details in this working paper. The resulting analytic expression for $H(z)/H_0$ may be convenient for exploration of the LW model. We present two approximation formulas for the Lambert $W$ function, highly accurate for
redshifts $z$ between 0 and 3, which may be useful for researchers who do not have ready access to a function library with the Lambert $W$ function. We also present a simplified proof of the analytic formula for another logarithmic integral which may be useful for exploring some variants of the LW model.
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All authors Ken Roberts, Francisco Javier Garcia-Sánchez, Subhajit Saha, S. R. Valluri
General Relativity and Quantum Cosmology
Scale dependence of the effective gravitational constant from functional renormalization group
Ruiqi Liang, Zhoujian Cao and Bing Sun
The general relativity may not be the final theory of
gravity. One possible way to look for the
gravity theory beyond general relativity is considering variable gravitational constant. Based on the
quantum field theory, the gravitational constant as the coupling constant of
gravity interaction may change along with the energy scale. Such scale dependent behavior of the gravitational constant can be well described by the functional renormalization group. In the current work, we investigate such behavior systematically. Firstly we find that such behavior is qualitatively independent of interactions such as the electromagnetic interaction included or not. But quantitatively the behavior is governed by two to-be-determined parameters. In general a limit scale may be introduced by the scale dependence of the gravitational constant. If we assume all physical scales are feasible, the two parameters are limited in some special regions. And more we compare the scale dependence behavior to the existing observations. We find the observation results constraint the two parameters strictly.
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Physics and Society
Control of Harmful Information Spreading on Adaptive Higher-Order Networks via Group Dissolution
Longzhao Liu, Zhihao Han, Xingru Chen et al. (+4 more)
Curbing harmful information contagion remains a critical challenge, motivating platform-level interventions such as group dissolution to sever transmission chains. However, in practice, users affected by dissolution often exhibit adaptive behavior, rewiring to form new groups. Yet, it remains unclear how these two mechanisms jointly shape information contagion and whether group dissolution remains effective in suppressing it. Here, we develop an adaptive higher-order contagion model that integrates platform-induced group dissolution with user adaptive rewiring, and derive a theoretical framework. Notably, we reveal an effective window for group dissolution, bounded by a critical infection rate. Above this threshold, dissolution backfires and amplifies information prevalence. Within this window, dissolution acts non-monotonically, initially exacerbating prevalence before eradicating contagion via a discontinuous transition beyond a critical dissolution rate. We further show that higher-order reinforcement expands this infection-rate window over which dissolution remains effective, whereas rewiring homophily substantially narrows it. Simulations on empirical hypergraph also validate these findings. Our work highlights the interplay between top-down platform interventions and bottom-up user adaptation, underscoring the need to account for adaptive responses when designing strategies to curb harmful information without unintended amplification.
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All authors Longzhao Liu, Zhihao Han, Xingru Chen, Chunyu Luo, Hongwei Zheng, Xin Wang, Shaoting Tang