Quantum Physics
Hudson's theorem fails for the SU(1,1) discrete series
Chon-Fai Kam
Hudson's
theorem states that a pure state of a bosonic mode has a non-negative Wigner function if and only if it is Gaussian. It underwrites the reading of Wigner negativity as a faithful signature of pure-state non-classicality. We show the statement has no analogue on curved phase space. For the positive discrete series of $SU(1,1)$, realised on the upper sheet of a two-sheeted hyperboloid, the Wigner-positive pure states form a strictly larger set than the Perelomov coherent orbit. Superpositions of the lowest weight state with the first excited state stay positive up to a mixing angle of $24.93^\circ$ at Bargmann index $k=1$, and the admissible set has positive volume, with a maximal width that is not attained in the two-state direction. We show analytically that the quadratic form controlling positivity degenerates in the far field onto a single mixing angle. That degeneracy bounds the window by $\arctan(1/\sqrt{2k})$ and leaves the threshold itself fixed at intermediate
hyperbolic distance.
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Quantum Physics
Asymmetric quantum error correction efficiently tackles application-specific noise effects
Abhishek Yadav, Peter K. Schuhmacher and Michael Epping
Noise is a major challenge for current
quantum computers. It can be broadly categorized into bit-flip and phase-flip errors. These two types do not necessarily affect the executed
algorithm, thus also the application, in the same way. We illustrate this general effect for the example of the
quantum approximate optimization
algorithm (QAOA) applied to a small instance of the flight-gate assignment (FGA) problem. We compare bit-flip and phase-flip Pauli noise under both layer-level and gate-level noise models, using two
circuit decompositions of the same ideal QAOA
unitary: a CNOT-based decomposition and a native-$R_{ZZ}$ decomposition. In the simulations, bit-flip noise produces the larger degradation in the performance of the
quantum optimization. The asymmetry is most visible in the layer-level and native-$R_{ZZ}$ simulations. We explain this by how the errors affect mixing, final measurements, and how they propagate inside the
circuit. We then exploit these insights to tackle noise particularly efficiently using asymmetric error-correcting codes. As an illustration, we use the
quantum parity code (QPC), a generalization of the 9-
qubit Shor code, and show that a smaller asymmetric code can achieve nearly the same improvement as a larger symmetric choice. This demonstrates that error-correction resources should be assigned not only according to physical error rates, but also according to how strongly each error channel affects the application. As a result, asymmetric
quantum error correction proves useful even in cases where the noise model is symmetric. Finally, we discuss how information about the noise obtained through calibration can be exploited in our approach.
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High Energy Physics (Experiment)
GNN-based track reconstruction for MUonE experiment
Damian Mizera, Mateusz Goncerz, Izabela Juszczak et al. (+3 more)
A study of a Graph Neural Network-based model for track reconstruction in the context of MUonE experiment is presented, using simulated data corresponding to the test-run MUonE detector setup. The fully three dimensional model successfully addresses both the reconstruction and particle identification challenges essential for achieving the experiment's primary physics goal. It provides significantly faster pattern recognition than classical reconstruction
algorithms, while maintaining comparable efficiency and resolution.
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All authors Damian Mizera, Mateusz Goncerz, Izabela Juszczak, Marcin Kucharczyk, Marcin Wolter, Milosz Zdybal
Quantum Physics
Power and Limits of Collective Local Measurements in Multicopy State Discrimination
Mao-Sheng Li, Yan-Ling Wang and Zhu-Jun Zheng
More than two decades ago, Bennett et al. [Phys. Rev. A 59, 1070 (1999)] asked whether perfect local discrimination of orthogonal
quantum states can require more than two copies. This question was subsequently answered for adaptive protocols that process the copies separately [Phys. Rev. Lett. 126, 210505 (2021)], but remained open when each laboratory is allowed to process its local copies collectively. Here we resolve this stronger setting and identify collective access across repeated local inputs as a distinct resource. For every fixed odd-
prime local dimension, there exist complete maximal-stabilizer eigenbases whose copy complexity under individual-copy separable measurements diverges with system size. Under collective processing this behavior changes sharply: every maximal-stabilizer eigenbasis in odd-
prime local dimension is perfectly decoded by one-round collective LOCC using at most three copies. Collective processing, however, does not remove multicopy hardness in general. For every fixed local dimension $d\ge2$, we prove the existence, within an explicit phase family, of complete bases whose copy complexity remains unbounded even under collective separable measurements, with a square root of the number of subsystems as lower-bound scale. Thus sample number, spatial measurement power, and coherent access across repeated local inputs are distinct resources in distributed
quantum measurement.
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Fluid Dynamics
Micro-convection mass transfer following bubble coalescence on a solid wall
Zahra Saadat, Michele Cattani, Amin Soltani et al. (+1 more)
The Volume-of-Fluid implementation in the \href{basilisk.fr}{Basilisk} flow solver is employed to study mass transfer after coalescence-induced jump-off of bubbles on solid substrates at four combinations of bubble radius ($R_m=150$ and 25 $\mu$m, hydrogen-water properties) and Schmidt number ($\text{Sc}=210$ and 1). The results show a relatively strong downward entrainment of low-concentration
liquid, induced by a rapid movement of the bubble interface at approximately 0.5 to 1 inertio-capillary time units after the moment of coalescence. At $\text{Sc}=210$, this leads to a highly local increase of the Sherwood number at a core region (roughly an area of radius $R_m/2$) below the south pole of the merged bubble, which persists long after the bubble departure due to the slow
diffusion at large $\text{Sc}$. The enhancement factor of the Sherwood number is highly dependent on the state of the mass-transfer boundary layer at the moment of coalescence, increasing with smaller boundary layer thicknesses. Shortly after the jump-off, the velocity of the bubble is considerably damped and rapidly approaches its free-rise terminal velocity. The effect of micro-convection on the wall mass transfer coefficient at this stage is insignificant when isolated, similar to what is reported in the literature for purely buoyancy-driven bubble rise – but slightly stronger.
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All authors Zahra Saadat, Michele Cattani, Amin Soltani, Pourya Forooghi
Mesoscale and Nanoscale Physics
Lindbladian Phase Geometry and Hall Transport in Open Bloch Systems
Zhihao Jiang, Longjun Xiang and Jian Wang
Quantum geometry underlies a wide range of transport phenomena in Bloch systems. How
quantum-
geometric transport is modified when Bloch electrons are coupled to an environment, however, remains largely unexplored, even though the environment can alter both the electronic state and the physical current operator. Here we formulate dc linear response within a trace-preserving Lindblad kinetic theory by defining the physical velocity as the Liouvillian time derivative of the position operator. This construction reveals an environment-induced contribution to the current vertex whose momentum-space curl generates new
Hall responses governed by the gauge-invariant phase geometry encoded by Lindblad jump amplitudes, which characterize electron-environment coupling. To leading order in the dissipative coupling, this geometry gives rise to interband shift-vector and diagonal-vorticity
Hall responses arising from off-diagonal and diagonal jump amplitudes, respectively. Remarkably, both mechanisms can produce a finite
Hall conductivity even when the conventional Berry-
curvature anomalous
Hall effect vanishes identically. Our work establishes Lindbladian phase geometry as an independent
geometric origin of transverse transport in open
quantum matter.
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High Energy Physics (Phenomenology)
Pseudo-Dirac Inelastic Dark Matter in the Leptophobic $U(1)_B$ Model: Confronting the LUX-ZEPLIN High-Recoil Event with Collider Searches
Xin-Yu Du, Wenjie Huang and Keping Xie
Interpreting the $248$~keV
nuclear-
recoil candidate reported by LUX-ZEPLIN (LZ) as an endothermic transition needs two ingredients usually put in by hand: a stable dark state, and a coherent current that is purely off diagonal. Gauging
baryon number supplies both. For the minimal dark charges $B(\chi_L)=-3/2$ and $B(\chi_R)=-9/2$, the scalars that generate the dark masses leave an exact residual parity $P=(-1)^{6B}$ stabilizing the lightest state, while the same Majorana masses make the vector current transition dominated as an identity rather than a choice. At $m_\chi=1$~TeV and $\delta=300$~keV the model is over-determined: the observed LZ interval, a leading-order relic estimate and the LHC dijet limit meet at the single perturbatively acceptable point $(M_{Z_B},g_B)\simeq(1.44~\mathrm{TeV},0.233)$. That point is allowed by currently existing searches but sits just below the trigger-level dijet boundary, so it is alive and not yet decided–and a re-run of that analysis on the Run-3 data at $\sqrt s=13.6$~TeV, already on tape, will exclude it or find it. Nor is the interpretation confined to that splitting: at $\delta=200$~keV, the same construction predicts a heavier mediator at comparable coupling, $M_{Z_B}\simeq2.4$-$3.0$~TeV with $g_B\simeq0.15$-$0.34$, a range the HL-LHC dijet program will probe.
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High Energy Physics (Theory)
Tachyon-massless couplings at order $\alpha'$ in bosonic string theory
Mohammad R. Garousi
Recently, it has been proposed that the classical effective action of bosonic string theory should contain only couplings with an even number of tachyon fields. We employ the T-duality procedure to derive such couplings at order \(\alpha'\) (four-derivative order) for the tachyon and massless fields. We first observe that, through higher-derivative field redefinitions of the tachyon potential term, one can choose a scheme in which, apart from the tachyon potential itself, all remaining couplings involve only covariant derivatives of the tachyon and the massless fields. We then construct a minimal basis of such couplings at four-derivative order, consisting of 14 independent terms. Imposing T-duality reduces this set to 6 nonzero couplings, expressed in terms of two unfixed parameters. One of these parameters is determined by matching to the known effective action in the zero-tachyon limit, while the other is fixed by comparison with the sphere-level S-
matrix element of four tachyon vertex operators. This latter comparison also establishes that the coefficient of the \(T^4\) term in the tachyon potential is positive. Remarkably, the tachyon mass term and this quartic term are consistent with a potential of the form \((2/\alpha')(-1+\cos T)\), which implies that the closed string tachyon condenses to the minimum of the potential at \(T=\pi\), thereby generating an Anti-de Sitter spacetime with cosmological constant \(\Lambda =-4/\alpha'\).
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Disordered Systems and Neural Networks
Finite-rank multiplicative perturbations of rotationally invariant non-Hermitian random matrices
Pierre Bousseyroux and Marc Potters
We study finite-rank multiplicative deformations of rotationally invariant non-Hermitian random
matrices. More precisely, we consider models of the form $\mathbf{A}(\mathbf{I}+\mathbf{T})$, where $\mathbf{A}$ is a large rotationally invariant non-Hermitian random
matrix, $\mathbf{T}$ is a finite-rank normal perturbation, and $\mathbf{I}$ denotes the identity
matrix. We characterize the emergence of outlier
eigenvalues, their fluctuations, and the associated eigenvector overlaps. Our results provide a multiplicative non-Hermitian counterpart to the classical Baik–Ben Arous–Péché framework.
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Materials Science
Angular compliance, not amplitude, governs the dielectric response of BaTiO3
Ryotaro Sahashi, Po-Yen Chen and Teruyasu Mizoguchi
Soft-mode theory specifies a frequency, not what a local polar unit does. What real-space motion underlies the dielectric response of BaTiO3 therefore remains unclear. Using electric-field-induced molecular dynamics with a machine-learning force field, we show that the permittivity tracks the field-induced angular redistribution of local Ti-O off-centering, not its magnitude. Temperature and biaxial strain modify the local structure through different microscopic routes, yet both dielectric responses collapse onto a common relation with the same orientational descriptor, providing a real-space counterpart to soft-mode behavior.
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Nuclear Experiment
Evolution of Spectroscopic Factors in Neutron-deficient $p$-shell Nuclei in connection with Short-Range Correlations
S. Koyama, D. Suzuki, O. Sorlin et al. (+31 more)
We report an uncertainty-controlled determination of
neutron-removal spectroscopic factors in the
neutron-deficient $p$-shell
nuclei $^{12}\mathrm{C}$, $^{10}\mathrm{C}$, $^{9}\mathrm{C}$, and $^{8}\mathrm{B}$, all measured under uniform conditions through exclusive ground-state-to-ground-state $(p,d)$ reactions at about 50 MeV/nucleon in a
liquid hydrogen target at the GANIL/LISE facility. The deuterons were detected in the highly-segmented MUST2 detector placed at forward angles and the excitation energy was reconstructed by the missing mass method. Several transitions, including a new state in $^7\mathrm{B}$, were observed. Differential cross sections, which display an $L=1$ pattern for all
nuclei, were fitted with 416 sets of uncertainty-quantified optical-model potential parameters and considering various single-particle bound-state wavefunctions to derive $C^2S$ values. The ratio between experimental and shell-model calculated values, $R_S$, is found to be slightly decreasing as a function of increasing
proton to
neutron separation energy asymmetry $\Delta S$, with a slope of $-0.0049(36)_{\rm stat}(13)_{\rm omp}(8)_{\rm s.p.}$. The observed trend is compatible with the phenomenological expectation that the short-range correlation effect on $C^2S$ increases with the degree of nucleon minority. The present data set delivers a high-precision
benchmark that will tightly constrain future microscopic descriptions of short-range correlations in asymmetric
nuclei.
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All authors S. Koyama, D. Suzuki, O. Sorlin, C. Hebborn, M. Assié, L. Lalanne, T. Abe, D. Beaumel, Y. Blumenfeld, L. Caceres, F. De Oliveira Santos, F. Delaunay, F. Flavigny, S. Franchoo, J. Gibelin, V. Girard-Alcindor, J. Guillot, F. Hammache, O. Kamalou, A. Kamenyero, N. Kitamura, V. Lapoux, A. Lemasson, A. Matta, B. Mauss, P. Morfouace, M. Niikura, H. Otsu, J. Pancin, T. Roger, T. Y. Saito, H. Sakurai, C. Stodel, J-C. Thomas
Chemical Physics
First-order Degenerate Symmetry-Adapted Perturbation Theory
Dominik Cieśliński, Tijs Karman, Anthony Scemama et al. (+2 more)
Degenerate electronic states govern the photophysics of excimers and the molecular dynamics near conical intersections. In regions where potential energy surfaces are degenerate or nearly degenerate, intermolecular interactions mix the corresponding electronic configurations. We introduce a first-order degenerate formulation of
symmetry-adapted perturbation theory (dSAPT) with weak
symmetry forcing that quantifies the mixing in terms of electrostatic and exchange (Pauli repulsion) contributions. We compare two alternative ways of resolving the degeneracy, in which antisymmetry is enforced either after or before diagonalization of the first-order eigenproblem. Using CASSCF monomer wave functions, we apply dSAPT to two model spatially degenerate systems, H$_2$–F(${}^2P$) and H$_2$–NO(${}^2\Pi$), and show that exchange effects contribute significantly to configuration mixing already at intermediate intermolecular separations. For the H$_2$–NO(${}^2\Pi$) complex, we further demonstrate that second-order dispersion energy is essential for qualitatively reproducing the angular dependence of the diabatic mixing angle. Finally, using water and benzene excimers with monomers described either by CASSCF or CIS wave functions, we show that Pauli repulsion controls delocalization of the excitation at short intermolecular separations.
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All authors Dominik Cieśliński, Tijs Karman, Anthony Scemama, Michał Hapka, Piotr S. Żuchowski
High Energy Physics (Experiment)
Leakage current evolution in LHCb VELO sensors during Run 1-2 LHC data taking period
M. Pycior, T. Szumlak, A. Oblakowska-Mucha et al. (+33 more)
Silicon detectors operating in the harsh mixed-
hadron radiation environment of modern high-energy physics experiments suffer progressive bulk damage, manifesting macroscopically as a steady rise in leakage current.
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All authors M. Pycior, T. Szumlak, A. Oblakowska-Mucha, K. Akiba, W. Barter, S. Borghi, T. Bowcock, E. Buchanan, J. Buytaert, S. de Capua, S. Chen, P. Collins, F. Dettori, L. Eklund, T. Evans, M. Gersabeck, T. Gershon, T. Hadavizadeh, K. Hennessy, W. Hulsbergen, D. Hutchcroft, M. John, P. Kopciewicz, P. Koppenburg, T. Latham, M. Majewski, C. Parkes, A. Poluektov, W. Qian, K. Rinnert, E. Rodrigues, M. Schiller, M. Smith, M. van Beuzekom, J. Velthuis, M. Williams
Quantum Physics
From NISQ to Fault-Tolerance: Applications and Algorithmic Benchmarks for Spin Qubits
Frederik Lohof, Florian Ginzel and Wolfgang Lechner
Motivated by recent breakthroughs in the development of
spin-based
quantum processing units based on exchange-only (EO)
spin qubits, we provide a roadmap for the implementation of
quantum algorithms on the EO platform, ranging from the NISQ to the fault-tolerant era. To provide an
algorithm-driven perspective on the scaling of
quantum chips, we consider a range of applications targeting different stages of hardware maturity and formulate requirements for a successful realization. We show that the compilation method Parity Twine perfectly complements the hardware's capabilities to perform tasks such as the
quantum Fourier transform or QAOA. Furthermore, we describe an error detection technique native to Parity Twine, which EO
qubits can leverage in a unique and advantageous way to improve
algorithm performance. Finally, since both near-term algorithmic
benchmarks and a long-term perspective can be found in digital
quantum simulation, we specifically discuss the fermionic fast
Fourier transform and the simulation of
Fermi-Hubbard models. The latter is explicitly discussed in the context of
quantum error correction and a partially fault-tolerant realization. By providing detailed resource estimates and identifying scaling bottlenecks on each level, our work offers a quantitative perspective on EO-based
quantum computing and will inform future hardware design choices.
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Materials Science
Groove-shaped defects in as-grown (001)-oriented $\beta$-Ga$_2$O$_3$ epilayers prepared by halide vapor phase epitaxy
Yongzhao Yao, Daiki Katsube, Hirotaka Yamaguchi et al. (+1 more)
Groove-shaped defects (GSDs) degrade the surface flatness of as-grown (001)-oriented $\beta$-Ga$_2$O$_3$ epilayers and necessitate chemical mechanical polishing before device fabrication, increasing processing costs and the risk of damage. We investigated the morphology, subsurface structure, and formation mechanism of GSDs in a homoepitaxial layer grown by halide vapor phase epitaxy using synchrotron X-ray topography and electron microscopy. The GSDs extended several millimeters along [010] and consisted predominantly of (-102) basal facets bounded by steep (100) sidewalls. Their wafer-scale distribution showed a spatial correspondence with variations in wafer
curvature, suggesting that local surface orientation influences GSD formation. Careful
alignment of surface images with transmission X-ray topographs revealed no one-to-one correspondence between GSDs and substrate defects, providing no evidence that substrate dislocations serve as their nucleation sites. Instead, transmission electron microscopy revealed planar defects localized near the terminal boundaries where the faceted GSD sectors met the surrounding (001) growth region; no such defects were observed in specimens extracted from the middle of GSDs. These defects exhibited {\alpha}-fringe contrast characteristic of inclined translational planar defects, with the dominant segments assigned to the (1-21) plane. The observations suggest that variations in local surface orientation and step supply may promote three-dimensional faceted growth, producing persistent (-102)/(100) sectors. The localized planar defects are therefore interpreted as consequences of growth-sector coalescence rather than the origins of GSD nucleation. These findings provide insight into the roles of wafer
curvature and surface step supply in GSD formation.
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All authors Yongzhao Yao, Daiki Katsube, Hirotaka Yamaguchi, Yukari Ishikawa
Quantum Physics
Remote Flux Refocuses Nonadiabatic Excursions in Compact-State Quantum Transfer
X. S. Meng, Y. S. Liu and X. Z. Zhang
Compact states embedded in a propagating band can carry
quantum information, but finite-time transfer can populate modes outside their subspace. We show that a remote flux can refocus this amplitude without changing the transfer states or the motion-induced coupling out of their subspace. In a resonator ring, this separation is exact because both endpoints of the flux-bearing bond are nodes of every compact transfer state. For the same pulse, zero and refocusing flux both produce substantial excursions, but only the latter yields near-complete logical transfer. Interference between
matrix amplitudes associated with different windings suppresses the endpoint error. Under matched control bounds, numerical optimization yields higher worst-input fidelity at the refocusing flux, providing a route to accurate transfer through coherent return.
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Quantum Gases
Precision tests of nonlinear and stochastic modifications of quantum mechanics with a 1D quantum gas
Yi Zeng, Angelo Bassi, Grigori E. Astrakharchik et al. (+3 more)
We propose a cold-atom platform for precision tests of nonlinear and
stochastic modifications to the Schrödinger equation, utilizing strongly correlated ultracold $^{133}$Cs in a uniform array of one-dimensional tubes formed by a two-dimensional optical
lattice. Objective collapse models can be tested using the metastable super-Tonks-Girardeau gas. Based on a calibration test performed on our existing experimental setup, we project a sensitivity to the Continuous Spontaneous Localization collapse rate of $\lambda_c \simeq 1.8\times10^{-11}\,\mathrm{s^{-1}}$ at a correlation length of $r_c = 10^{-7}\,$m. This would establish a new bound an order of magnitude below the strongest existing constraint that remains robust against a cutoff in the collapse noise spectrum. Additionally, we can test deterministic nonlinear modifications by probing the
symmetry-protected breathing mode frequency of the Tonks-Girardeau gas in harmonic traps. Crucial to both measurement schemes is the capability to independently tune the atom number and the linear density. By exploiting the different scaling laws associated with these parameters, we can cleanly distinguish genuine new physics signals from technical systematics.
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All authors Yi Zeng, Angelo Bassi, Grigori E. Astrakharchik, Yanliang Guo, Manuele Landini, Hanns-Christoph Nägerl
High Energy Physics (Phenomenology)
Chiral Doubling, Renormalization Group Fixed Points, and Dense Matter Equations of State
Chihiro Sasaki
We review a top-down fixed-point-extrapolation paradigm as a unified effective field theory framework for hadronic spectroscopy, dense baryonic matter, and compact
star physics. By formulating our effective Lagrangian directly at renormalization group (RG) fixed points and introducing minimal
symmetry breaking, we extrapolate the theory back to physical environments. In the
vacuum, this framework naturally reproduces the heavy-light
meson parity-doubling spectrum via light vector
meson loops. In dense matter, the interplay between the
chiral-invariant nucleon mass m0 and walking vector couplings reconciles gravitational-wave constraints with $2M_\odot$ massive
neutron stars. Generalization to a
quark-
hadron hybrid approach further illuminates sequential deconfinement, core stability, and
baryon number fluctuations, demonstrating how underlying RG fixed points dictate hadronic dynamics from
vacuum to
neutron star interiors.
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High Energy Physics (Phenomenology)
Hadronic heavy neutral lepton decays to the limit
Jonathan L. Schubert and Babette Döbrich
Heavy Neutral
Leptons are a class of hypothetical particle, motivated by simultaneously solving multiple of the standing issues of the Standard Model. In this work we investigate the decay structure of this type of particle in the hadronic picture for multi-body final states. We propose to link the resulting hadronic description to a partonic description in a seamless transition based on the
hadron system's invariant mass. Beyond the impact on the total HNL lifetime, we will show that the multi-
hadron channels emerging in this description can constitute interesting experimental signatures.
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Mathematical Physics · Cross-listed from math.NA
Structure-Preserving Data-Driven Identification of Port-Hamiltonian Differential-Algebraic Systems
Tom Zwerschke, Matthias Ehrhardt, Michael Günther et al. (+1 more)
We present a data-driven approach to identifying linear index-1 differential-algebraic pH systems (pH-DAEs) based on input-output measurements. In comparison to the identification of port-
Hamiltonian (pH) systems, the algebraic constraint and the index condition pose additional challenges. First, we establish a structure-preserving formulation of the considered pH-DAE class and derive an implicit midpoint discretization that preserves the algebraic constraints and discrete dissipation inequality. We formulate the identification problem as a regularized least-squares minimization problem subject to the pH-DAE dynamics. Exploiting the index-1 structure, we reduce the constrained problem to an unconstrained optimization problem over the system parameters while preserving the port-
Hamiltonian structure. Next, we derive an adjoint-based formulation to efficiently evaluate the gradient of the resulting reduced cost functional. This enables us to use gradient-based optimization methods for parameter estimation. Under suitable assumptions on the admissible parameter set, the existence of a minimizer is established. Numerical experiments demonstrate that the proposed approach can identify surrogate pH-DAE systems that accurately reproduce the input-output behavior of reference systems. Further investigations show the approach's potential for identifying reduced-order surrogate models. Cross-validation with independent input signals confirms the predictive capability of the identified models.
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All authors Tom Zwerschke, Matthias Ehrhardt, Michael Günther, Claudia Totzeck
Instrumentation and Methods for Astrophysics
One Merger, Three Bands: Multiband Detection Rates and Parameter Estimation of Stellar-mass Binary Black Hole Coalescences from Millihertz to Kilohertz
Anson Chen and Jun Zhang
Stellar-mass binary black holes sweep through the millihertz, decihertz, and kilohertz gravitational-wave bands before merger, making them
prime targets for multiband observations. We forecast their detection rates and parameter-estimation precision for networks combining the millihertz observatories LISA, Taiji, and TianQin; the decihertz concepts LGWA, AMIGO, and AMIGO-5; and the ground-based LVK and
Cosmic Explorer. Using the binary-black-hole mass and
redshift distributions inferred from GWTC-4, we first estimate the single-band yields and then account explicitly for detector lifetimes and relative mission start times when calculating multiband rates. For a signal-to-noise-ratio threshold of 8, the LISA–Taiji–TianQin network is expected to detect $53.6^{+19.7}_{-14.1}$ systems in the millihertz band, while the largest three-band yield is $23.5^{+8.7}_{-6.2}$ events for LISA–Taiji–TianQin combined with LGWA. The yield is maximized when the decihertz observation begins approximately $0$–$3\,{\rm yr}$ after the millihertz mission. Ground-informed subthreshold searches with a threshold of 5 increase the multiband yields by a factor of approximately $4$–$5$, reaching $125.1^{+46.1}_{-32.9}$ events for the same network. Fisher-
matrix forecasts for a GW150914-like source show that decihertz observations provide the dominant improvement in most multiband parameter constraints, whereas millihertz data primarily sharpen the detector-frame chirp mass and sky localization. Combining the three bands improves the chirp-mass precision by orders of magnitude relative to ground-based observations alone and can reduce the localization area and coalescence-time uncertainty substantially. These results demonstrate that coordinated mission scheduling and targeted subthreshold searches are essential for realizing the scientific potential of
stellar-mass multiband gravitational-wave astronomy.
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Plasma Physics
Dual-decomposition multi-GPU particle-in-cell method for cylindrical plasmas: Batched Fourier-mode multigrid and balanced particle slabs
Yinjian Zhao, Xi Chen and Yingjie Chen
Three-dimensional electrostatic particle-in-
cell (PIC) simulations combine irregular particle operations with a globally coupled Poisson solve, whose preferred parallel decompositions conflict. We introduce a dual-decomposition multi-GPU method: complete azimuthal
Fourier modes are owned during the field solve, whereas spatial slabs own particles. Exact full-spectrum diagonalization and batched
matrix-free
geometric multigrid keep collectives outside the V-cycle, after which every GPU reconstructs the full field. Peer migration,
cell reordering, warp-aggregated deposition, and capacity-constrained dynamic cuts restore particle locality and balance. CPU/GPU Poisson solutions agree to relative L2 errors below 6.9e-16; all 65 physical modes on eight V100 GPUs are solved in 9.350 ms with relative errors below 8.2e-15. For an identical 512*128*400 problem containing 707,788,800 particles per species, the complete PIC loop reaches 0.149108 s per step and strong-scales from five to eight GPUs with 91.81% efficiency. A separate cross-resolution production study shows approximately threefold aggregate particle-update and Poisson-
cell throughput relative to a single RTX 5090 calculation; this measures refined-problem capability rather than a hardware speedup or formal convergence order.
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Applied Physics
Boundary-induced medium mapping enables air-equivalent acoustic propagation and perfect absorption in water
Mingyu Duan, Xiangjun Peng, Ying-Jing Qian et al. (+1 more)
The extreme water-air impedance contrast (~3600) has long acted as a fundamental barrier separating airborne and
underwater acoustics. Here, we overcome this barrier with flexible boundaries, which establish a direct physical mapping between disparate acoustic media, enabling a water-filled channel to emulate air-equivalent wave propagation. Through vibroacoustic coupling, the effective wave velocity is rescaled in an approximately nondispersive manner, producing slow waves with tunable attenuation. Leveraging this concept, we demonstrate broadband
underwater sound absorption at a deep-subwavelength thickness approaching the causal limit. Our findings reveal that acoustic media can be reshaped via boundary dynamics rather than bulk composition, paving the way for transplanting acoustic functionalities and metamaterial design across distinct media.
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All authors Mingyu Duan, Xiangjun Peng, Ying-Jing Qian, Tian Jian Lu
Statistical Mechanics
Reverse engineering of mechano-kinetic parameters from stochastic force profiles in heterogeneous ensembles of molecular motors and tracks
Valentina Buonfiglio, Irene Pertici, Pasquale Bianco et al. (+2 more)
Heterogeneity in contractile systems of molecular motors interacting with their tracks plays a key role in numerous cellular physiological and pathological processes. However, its effects cannot be captured by theoretical models assuming identical mechano-kinetic properties for all motors. We developed a
stochastic framework to describe heterogeneous ensembles of myosin motors comprising two populations with distinct mechano-kinetic properties. Assuming that motors interact with the actin filament (their track) as independent force generators, we derived the probability distribution of the isometric force and characterised the statistics of finite-size force fluctuations. The proposed framework includes an estimation procedure that simultaneously infers the mechano-kinetic parameters and the size of the motor ensemble, eliminating the need to prescribe it a priori. Validation against synthetic and experimental data shows the model accurately captures force fluctuations and provides realistic estimates of the ensemble size. Furthermore, the framework enables a quantitative assessment of ensemble heterogeneity and the inference of an unknown motor species properties. This approach provides a quantitative tool for characterising heterogeneous actin-myosin systems, such as those arising from the co-presence of different
protein isoforms in cardiac and skeletal muscle, or from the partial replacement of native
proteins with mutation-derived or engineered variants.
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All authors Valentina Buonfiglio, Irene Pertici, Pasquale Bianco, Duccio Fanelli, Stefano Gherardini
High Energy Physics (Phenomenology)
Probing Neutral Triple Gauge Couplings at e- p colliders
Xue-Jia Cheng, Chong-Xing Yue, Ji-Chong Yang et al. (+1 more)
The Standard Model Effective Field Theory~(SMEFT) has attracted much
attention as a model-independent way for probing new physical signals. In the SMEFT framework, $e^{-}p$
colliders can be used to study new interactions of gauge
bosons, such as neutral Triple Gauge Couplings~(nTGCs). We study the signals and backgrounds of six different processes at the Future Circular
Collider-
hadron electron~(FCC-he) and propose different event selection strategies. The expected constraints on the coefficients of the dimension-8 operators for each process, as well as the combined constraints are obtained. The results show that the sensitivity of $e^{-}p$
colliders to nTGCs is similar to the current Large
Hadron Collider~(LHC) experiments and is more competitive than that of Circular Electron Positron
Collider~(CEPC) experiments.
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All authors Xue-Jia Cheng, Chong-Xing Yue, Ji-Chong Yang, Si-Tong Liu
General Relativity and Quantum Cosmology
The (in)stability on total transmission modes with small bumps
Xi-Ning Dong, Liang-Bi Wu, Yu-Sen Zhou et al. (+1 more)
Total transmission modes (TTMs) are a class of reflectionless solutions to black hole perturbation equations, closely related to quasinormal modes (QNMs), and can exhibit significant sensitivity to weak environmental perturbations. In this work, we investigate the spectrum (in)stability of TTMs of Tangherlini black holes by introducing a localized Pöschl-Teller bump perturbation into the effective potential, and employ a modified Chebyshev-Lobatto grid to improve the numerical accuracy of the localized perturbation. For $d=14$, $\ell=2$, and $s=2$, the purely imaginary TTM exhibits relatively strong spectrum stability, whereas the genuine complex TTMs undergo significant migrations even for small perturbations, consistent with the spectrum stability revealed by previous pseudospectrum analyses.
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All authors Xi-Ning Dong, Liang-Bi Wu, Yu-Sen Zhou, Zong-Kuan Guo
Quantum Physics
Electron beam driven collective self hybridized exciton polaritons
Parsa Darman, Maximilian Black, Prabhdeep Singh et al. (+5 more)
Self-hybridized
exciton polaritons in layered
semiconductors emerge from the hybridization of excitonic resonances with confined photonic modes in films and provide a versatile platform for controlling light–matter interactions at the nanoscale. Yet, the nature of
exciton–
photon interactions and the collective and synchronous strong coupling of multiple
excitons to the same photonic mode remain largely unexplored. Here, we use complementary momentum-resolved photoluminescence and cathodoluminescence spectroscopy to compare self-hybridized
exciton polaritons in Ruddlesden–Popper perovskite flakes under optical and electron-beam excitation. We find that cathodoluminescence exhibits remarkably larger polaritonic level repulsion than photoluminescence, revealing an enhanced effective coupling strength under electron-beam excitation. We attribute this enhancement to the collective coherent excitation of multiple
excitons by fast electrons, which couple to the same photonic mode and increase the interaction strength according to a $g_N=g_1\sqrt{N}$ scaling, with an effective number of up to $N\approx23$ coherently coupled excitonic oscillators. By reducing the electron kinetic energy, we further uncover a crossover to a partially incoherent excitation regime in which higher-order Fabry–Pérot
exciton-polariton resonances disappear, leaving only the lowest polariton branches while coherent transition radiation persists. This transition arises because low-energy electrons excite
excitons over extended spatial volumes, washing out the phase coherence required to sustain collective coupling and form polaritonic resonances. Our work shows that electron beams can actively modify collective light–matter coupling in layered
semiconductors and establishes cathodoluminescence as a route to access excitation regimes beyond all-optical excitation schemes.
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All authors Parsa Darman, Maximilian Black, Prabhdeep Singh, Masoud Taleb, Victor DeManuel-Gonzalez, Sara Darbari, Fatemeh Chahshouri, Nahid Talebi
Biological Physics
On the variational framework employing optimal control for biochemical thermodynamics
Adam Moroz and David Ian Wimpenny
The maximum energy dissipation principle can be successfully applied to describe a range of basic nonlinear models. The application of the general variational framework (Moroz, 2008, 2009, 2010) has been illustrated for basic linear schemes. The study presented in the paper shows how the kinetic processes at this level of the biomolecular and biophysical phenomena can be effectively described in terms of the maximum energy dissipation principle and its variational formulation. On the basis of this approach, a range of Lagrangians was proposed for basic nonlinear dissipative kinetic models. The results of this study show that the framework is in agreement with nonlinear
equilibrium thermodynamics.
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Applied Physics
Physics-Constrained Inverse Estimation of Irradiation-Induced Strain in He-H Ion-Implanted 4H-SiC Using Nanoindentation and Finite Element Modeling
M. Bensalem, N. Daghbouj, J.Duchon et al. (+8 more)
Nanoindentation is widely used to evaluate the mechanical properties of irradiated materials however its potential for quantifying irradiation induced subsurface strain remains underexplored. In this work, an integrated experimental numerical framework based on a physics constrained inverse modeling approach is employed to estimate the magnitude of a depth dependent irradiation induced strain distribution in single
crystal 4H SiC following sequential He and H ion implantation. The approach combines depth sensing nanoindentation, finite element modeling FEM, and a simplex based inverse optimization routine to calibrate a physically motivated eigenstrain profile derived from ion damage simulations. The strain field is assumed to follow a lognormal distribution consistent with independently determined damage profiles SRIM, and is implemented in the FEM model through a depth dependent thermal expansion formulation. By minimizing the squared error between simulated and experimental force displacement curves, the peak tensile strain is estimated to be 0.91, accompanied by an effective Young s modulus of 310 GPa and a yield strength of 16.4 GPa. Independent validation using nano beam precession electron diffraction N PED confirms good agreement between the reconstructed and experimentally measured out of plane strain profiles in both magnitude and spatial distribution. The results demonstrate that nanoindentation, when combined with physics based inverse modeling, can provide a practical tool for quantifying irradiation-induced strain and residual stress in
nuclear ceramics. This methodology offers a complementary approach to diffraction based techniques for assessing subsurface damage in ion irradiated materials relevant to advanced
nuclear systems.
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All authors M. Bensalem, N. Daghbouj, J.Duchon, B.S. Li, A.T. AlMotasem, S. Magalhaes, A. Yie, F. Munnik, Xin Ou, W.J. Weber, T. Polcar
Quantum Gases
Nonequilibrium full counting statistics of multicomponent strongly-interacting quantum gases with defects
Ovidiu I. Patu, Oleksandr Gamayun and Catalin Pascu Moca
We investigate the full counting statistics of a one-dimensional multicomponent impenetrable gas released from a bipartite state in the presence of a local defect.
Spin–charge separation reduces the multivariate generating function to an exact Fredholm determinant whose kernel is built from time-evolved single-particle orbitals. Expressing these orbitals in terms of scattering data gives access to both transient dynamics and the nonequilibrium steady state. We derive the leading long-time asymptotics and identify persistent oscillations in densities and currents caused by multiple bound states at the junction. We argue that interactions between components lead to a linear low-temperature correction to the current, in contrast to the quadratic correction in the single-component case. At
equilibrium, we obtain the M-Wright distribution of
spin transfer with $t^{1/4}$ scaling.
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