Materials Science
Symmetry Classification of Non-Relativistic Hidden Spin Polarization in Noncollinear Magnets
Yuzhong Hu, Pan Zhou, Baoru Pan et al. (+2 more)
Hidden
spin polarization (HSP), in which
spin-polarized states exist locally while the total
spin polarization are hidden in momentum space, has been extensively studied in nonmagnetic and collinear
magnetic systems, but remains largely unexplored in noncollinear magnets. Here we establish a unified
symmetry framework for HSP in noncollinear
magnetic materials based on
spin-group theory. We show that
spin symmetries systematically constrain nonrelativistic
spin polarization, giving rise to four distinct split
spin-texture (SST) types for each local sector, denoted as SST-1, SST-2, SST-3, and SST-4. Based on these splitting forms, together with the dimensionality of the associated local
spin textures and the
symmetry relations between different local sectors, we further classify HSP into three categories: HSP-1, HSP-2, and HSP-3. We illustrate these categories using tight-binding models and representative material examples, including SrFe$_2$Se$_2$O, USb, Sr$_2$Mn$_3$Sb$_2$O$_2$, PrFeAsO, and GdMn$_2$Si$_2$. A survey of the MAGNDATA database further identifies 133, 7, and 139 candidate noncollinear
magnetic materials hosting HSP-1, HSP-2, and HSP-3, respectively. In addition, our
symmetry analysis and first-principles calculation show that many of these materials can exhibit nonzero
spin-related response tensors. These results establish a general framework for understanding HSP in noncollinear magnets and highlight their potential for
spin-dependent functionalities.
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All authors Yuzhong Hu, Pan Zhou, Baoru Pan, PengBo Lyu, Lizhong Sun
Mesoscale and Nanoscale Physics
Floquet spintronics: tuning the current-induced spin polarization of topological surface states with light
Youngjae Kim, Aayushi Agrawal and Kwon Park
Topological surface states are a promising platform for spintronics due to
spin-momentum locking.
Spin-momentum locking can induce a net
spin polarization in topological surface states via an electric current, a phenomenon known as the Edelstein effect. In this work, using Floquet theory, we show that the current-induced
spin polarization of topological surface states can be tuned by illuminating them with light, thereby modifying their
spin texture in momentum space. Specifically, the electric
spin susceptibility of topological surface states can be controlled and even reversed by varying the electric-field strength of high-frequency, circularly polarized light.
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Quantum Physics
Quantum-State Projectors on Grassmannian: Geometry, Holonomy, and Topology
Shin-Ming Huang
An isolated group of $k$ bands in an $N$-level
quantum system defines a rank-$k$ spectral projector and hence a map into the complex Grassmannian $\mathrm{Gr}(k,N)$. For a smooth gapped
Hamiltonian, this projector is globally smooth and periodic even when band
topology obstructs a globally smooth periodic, or
symmetry-compatible, Bloch frame. We take the globally defined differential $\dd P$ as the central object: it is the tangent field of the Grassmannian map, removes unphysical rotations within the selected subspace, and retains the physical interband transition. The interband block of this tangent data simultaneously determines the
quantum metric and Berry
curvature; the associated horizontal generator produces finite Grassmannian motion, while wedge products of $\dd P$ enter topological forms. We construct a shortest path between two projectors in the ambient Grassmannian and show that the singular values of its horizontal generator block are the principal angles between the endpoint subspaces. This construction provides a piecewise-geodesic interpretation of discrete
geometric phases. In a separate development, we derive a basis-independent expression for the determinant of a multiband Wilson loop from traces of powers of an ordered projector product, without decomposing a degenerate band multiplet into individual bands. Finally, the same tangent-vector calculus organizes Chern characters,
chiral winding numbers, and the time-reversal $\mathbb Z_2$ index. The resulting framework unifies local
quantum geometry, finite subspace distance, holonomy, and
topology while avoiding global gauge fixing.
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Strongly Correlated Electrons
Prominent Intrinsic Orbital Hall Effect in the 135 Kagome Metal Family and Orbital Responses in the Loop-Current Phase
Jianxin Huang, Rina Tazai, Youichi Yamakawa et al. (+1 more)
The study of electronic orbital degrees of freedom, including the generation and control of orbital currents and orbital angular momentum, has emerged as a vibrant research field. Here, we study the orbital
Hall effect (OHE), one of the key mechanisms for orbital current generation, in transition-metal kagome-
lattice metals. We propose a large positive OHE in CsTi$_3$Bi$_5$ and negative OHEs in CsV$_3$Sb$_5$ and CsCr$_3$Sb$_5$ models. Orbital-sector decomposition shows that the $\vert l^z_d \vert=2$ $d$-orbital channel gives a positive contribution, whereas the $\vert l^z \vert=1$ $d$- and $p$-orbital channels can give negative contributions. Control calculations suggest a persistent orbital-sector sign tendency near the actual filling, while strong $p$-$d$ hybridization modulates the quantitative balance and total OHE sign. Thus, the compound and filling dependence of the OHE reflects both the sign tendency of each orbital sector and the hybridization-controlled balance among them. Furthermore, we investigate the loop-current phase of CsV$_3$Sb$_5$ and show that it induces finite local atomic orbital angular momentum. We also show that loop-current-related
symmetry lowering allows finite symmetric components of the orbital conductivity tensor. This study provides a basis for exploring orbital currents and local orbital-angular-momentum responses in strongly correlated kagome metals.
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All authors Jianxin Huang, Rina Tazai, Youichi Yamakawa, Hiroshi Kontani
Physics and Society
Agentic Artificial Intelligence for Reproducible Human-in-the-Loop Environmental Health Research
Edmund Seto
Agentic artificial intelligence (AI) systems that are capable of planning and executing multi-step analytical tasks are increasingly available to environmental health researchers, but their reliability in real-world practice has not been fully explored. This paper describes a human-in-the-loop agentic framework for environmental health research, involving the review, verification, and correction of AI-generated data analysis code and results at each step - a process that mirrors the mentorship structure of traditional research teams. This approach offers a path toward rigorous, reproducible use of agentic AI in routine data-rich environmental health research. We illustrate this framework through a case study analyzing nitrogenous organic contaminants at U.S. Superfund sites, a chemical family linked to the emerging tire-derived contaminants 6PPD and 6PPD-quinone. Using an agentic large
language model to generate R code for data filtering, spatial mapping, and cluster analysis, we document instances where initial agentic AI outputs benefited from a human-in-the-loop process to produce more rigorous and reproducible results. We conclude that effective use of agentic AI requires both domain expertise to frame questions and evaluate outputs, and coding literacy to guide the AI's approach, while outlining future opportunities for agentic AI workflow to advance the environmental health sciences.
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Plasma Physics
Linear and nonlinear benchmark of gyrokinetic simulation of energetic particle driven toroidal Alfven eigenmodes in ITPA TAE benchmark case
Youjun Hu, Yang Chen, Lei Ye et al. (+2 more)
A new gyrokinetic code, TEK, was benchmarked in simulating energetic particle (EP) driven toroidal Alfven eigenmodes (TAEs) in the simple tokamak configuration chosen by the ITPA-EP group for code benchmarking purpose. Linear
benchmark has been well established by other codes, whereas nonlinear
benchmark for this case is lacking. This paper presents, besides the linear
benchmark, nonlinear results for both single-n and multiple-n simulations (n is the toroidal mode number). The nonlinear results are in good agreement with an analytical theory on zonal field beat-driven by Alfven eigenmodes, partially verifying correctness of the nonlinear simulations. The saturation level and the resulting EP transport are examined. This provides data for future inter-code nonlinear benchmarking. In TEK, all species (electrons, thermal ions, EPs) are treated on the same footing using the gyrokinetic model (with electrons in the zero Larmor radius limit). The electromagnetic cancellation problem is mitigated by using the mixed-variable pullback method. Numerical details related to electromagnetic gyrokinetic simulation are discussed.
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All authors Youjun Hu, Yang Chen, Lei Ye, Zhiyong Qiu, Youwen Sun
Materials Science
Optical Anisotropy and Phase Matching in Non-Centrosymmetric Perovskite Oxides from DFT+U and DFT+U+V Functionals
Mohamed S.M.M. Ali and Ismaila Dabo
Optical anisotropy underpins the operation and performance of a broad range of photonic and
quantum technologies. In this work, we critically examine the accuracy of density functional theory approximations with onsite and intersite Hubbard corrections (the DFT+$U$ and DFT+$U$+$V$ functionals) in predicting the anisotropic optical response of the non-centrosymmetric perovskite
oxides, such as BaTiO$_3$, LiNbO$_3$, KNbO$_3$, and PbTiO$_3$. It is found that correcting self-interaction errors using DFT+$U$ alone does not capture the optoelectronic response of these materials, often leading to a suppression of their optical anisotropy. While intersite Hubbard interactions restore this anisotropy, the choice of the (inter)atomic orbital
manifold that defines the Hubbard correction remains critical to its accuracy. The predictive performance of the resulting, systematically validated DFT+$U$+$V$ functional is achieved at a fraction of the computational cost of hybrid functionals and many-body perturbation theory calculations. As
benchmarks, we investigate Zn- and (Bi,Mn)-substituted BaTiO$_3$ solid solutions; the latter exhibit polarization-dependent bandgap narrowing from mid-gap states, substantially enhancing the dichroic ratio and birefringence with promising implications for polarization-sensitive photodetectors and integrated photonics.
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High Energy Physics (Theory)
Notes on the Graph-Encoded Manifolds for the (Genuine) Multi-Entropy
Norihiro Iizuka
Genuine multi-
entropy is the part of the $\mathtt{q}$-partite multi-
entropy that captures
entanglement genuinely shared among all $\mathtt{q}$ parties, rather than
entanglement already present among fewer subsystems. It was recently proposed that this genuine part – so-called a multipartite
entanglement signal – can be studied via the graph-encoded
manifold (GEM) built from the underlying $\mathtt{q}$-partite multi-
entropy permutation family: reading its $\mathtt{q}$-colored contraction graph $\Gamma_{\mathtt{q},n}$ as a triangulation by $(\mathtt{q}-1)$-simplices. Focusing on $\mathtt{q}=4$, we classify the
topology of every vertex link of $\Gamma_{4,n}$ and find $\chi_{\rm link}(n)=n(3-n)$: the graph satisfies the GEM condition, namely every vertex link is a two-sphere, if and only if $n=2$, while for every $n\geq3$ the vertex links are closed surfaces of strictly positive genus $g_n=\tfrac12(n-1)(n-2)$, so that the graph instead defines a simplicial complex with a conical singularity at every vertex.
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Nuclear Theory
Quantum simulation of bottomonium dynamics in the quark-gluon plasma via the Lindblad equation
Linyuan Wei, Jin Hu, Anping Huang et al. (+2 more)
Quantum computing provides a powerful framework for simulating real-time dynamics in open
quantum systems, offering key advantages for modeling heavy-quarkonium transport in high-energy
nuclear collisions. In this work, we perform
quantum simulations of the isotropic next-to-leading-order Lindblad equation for bottomonium in the
quark-
gluon plasma using a reduced spherical coordinate representation. We discretize operators and wavefunctions, map the physical state onto
qubits, and execute time
evolution via parameterized
quantum gate operations. By extracting the $\Upsilon(1S)$ survival probability, we quantitatively isolate the color-octet contribution, demonstrating that its overall impact is small in the final production of the bottomonium ground state $\Upsilon(1S)$ in the hot QCD medium at temperatures accessible at the Large
Hadron Collider. Additionally, we have further optimized the
quantum simulation
algorithm for the Lindblad equation. The improved
algorithm requires only a single ancillary
qubit to realize the Lindblad
evolution, thereby minimizing the
circuit significantly.
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All authors Linyuan Wei, Jin Hu, Anping Huang, Yunpeng Liu, Baoyi Chen
Earth and Planetary Astrophysics
An Observational Study of Systematics in Differential Transmission Spectroscopy Using HFOSC on the Himalayan Chandra Telescope
Manjunath Bestha, Athira Unni, T Sivarani et al. (+2 more)
Ground-based low-resolution transmission spectroscopy requires photometric precision of a few hundred parts per million, making it sensitive to instrumental and atmospheric systematics. This work studies the systematic effects affecting differential transmission spectroscopy using the Hanle Faint Object Spectrograph Camera (HFOSC) on the 2-m Himalayan Chandra
Telescope (HCT). The study was motivated by an additional flux drop observed in the white-light curve of HAT-P-1 b. HAT-P-1 b is an ideal target for differential spectrophotometry because it has a visual binary companion with similar brightness at a suitable separation, allowing the companion
star to be used as a reference. To investigate the origin of this feature, we analyzed several observational parameters, including FWHM variations, spectral trace motion, centroid drift, and spectral shifts. We also observed WASP-33 b in slitless mode to test whether differential slit losses could explain the observed systematic. In addition, observations of WASP-12 b were used to derive a broadband optical transmission spectrum using common-mode correction. The additional flux drop is unlikely to be caused only by differential slit losses, since similar differential centroid and spectral shifts are present in both slit and slitless observations. The results suggest that the observed systematic may be related to field-dependent distortions and pointing-dependent instrumental flexure, although its exact cause is still unknown. Overall, this work highlights the importance of understanding and reducing observational systematics in ground-based
exoplanet transmission spectroscopy, especially for measurements that require photometric precision of a few hundred parts per million.
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All authors Manjunath Bestha, Athira Unni, T Sivarani, Parvathy M, Devika Divakar
Medical Physics
108 ps coincidence time resolution through optimized scintillators, photodetectors, readout electronics, and DOI-based timing correction in orthogonally stacked detector configurations
Arisa Sanzen, Yuya Onishi, Takahiro Moriya et al. (+2 more)
Objective. Existing commercial time-of-flight positron emission
tomography (TOF-PET) systems yield a coincidence time resolution (CTR) of ~200 ps or less full width at half maximum (FWHM). Recently, there has been a challenge to achieve a CTR of 100 ps FWHM at the system level. However, current silicon photomultipliers (SiPMs) and 20-mm-thick scintillators in conventional single-ended readout scheme is difficult to achieve 100 ps CTR; the
photon transport time spread (PTS) within the scintillator
crystal is a major barrier. Differences in the interaction position result in variations in PTS on the order of several tens of ps, thereby degrading the CTR. A shorter scintillator can improve CTR; however, this can degrade detection efficiency. Approach. To overcome this trade-off between the CTR and detection efficiency, we previously proposed xDetector, an orthogonally stacked configuration along the longitudinal axis of scintillator
crystals. We investigated the CTR potential of the xDetector by improving the scintillator, photodetector, and readout electronics, and by applying CTR correction based on a three-dimensional interaction within the scintillator. Main results. Based on error propagation, the CTR of the paired xDetector was calculated as 113.5 $\pm$ 2.7 ps FWHM. Furthermore, the CTR of the xDetector was measured at four positions along the longitudinal axis by manually sliding the xDetector, and the corrected achieved CTR was 108.6 $\pm$ 1.9 ps FWHM. Moreover, compared with the conventional single detector using a 20.0 mm scintillator, CTR improved by an average of 10.3%. Significance. The xDetector offers potential as a PET detector concept to achieve a CTR of 100 ps FWHM. Such timing performance is expected to improve TOF-PET image quality and quantitative accuracy, contributing to more reliable disease detection and diagnosis than current PET detectors.
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All authors Arisa Sanzen, Yuya Onishi, Takahiro Moriya, Tomohide Omura, Ryosuke Ota
High Energy Astrophysical Phenomena
Probing Variations in Earth's Ionosphere Using Pulsars
Yanqing Cai, Ziwei Wu, Weiwei Zhu et al. (+24 more)
We present high cadence 10-minute rotation measure (RM) monitoring of PSR~J0814+7429 using the LOw-Frequency ARray, aiming to probe ionospheric variability along the
pulsar line of sight (LoS). By separating the ionospheric contribution from the observed RM, we quantitatively reconstruct the diurnal variation of the ionospheric electron density along the
pulsar LoS based on the World
Magnetic Model. The derived variations exhibit clear
solar-driven modulation, including the ionospheric noontime bite-out phenomenon, and show good agreement with the LoS total electron content reconstructed from independent global vertical total electron content maps. These results demonstrate the feasibility of using
pulsars as probes of temporal variations in the electron density of the Earth's ionosphere.
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All authors Yanqing Cai, Ziwei Wu, Weiwei Zhu, Joris P. W. Verbiest, Ningbo Wang, Moochickal Ambalappat Krishnakumar, Lars Künkel, Jörn Künsemöller, Yulan Liu, Nataliya Porayko, Golam M. Shaifullah, Caterina Tiburzi, Marcus Brüggen, Ralf-Jürgen Dettmar, Ziyao Fang, Qiuyang Fu, Jiawei Jin, Caisong Liu, Lingqi Meng, Xueli Miao, Jiarui Niu, Dominik J. Schwarz, Christian Vocks, Mengyao Xue, Mao Yuan, Youling Yue, Zhen Zhang
Chemical Physics
High-temperature simulation of the Raman spectra of the isotopologues $^{13}$C$^{16}$O$_2$ and $^{16}$O$^{13}$C$^{18}$O
Eduardo Suárez, Christian Ostertag-Henning, Miguel Carvajal et al. (+1 more)
Recently, experimental Raman spectra of the isotopologues $^{13}$C$^{16}$O$_2$ and $^{16}$O$^{13}$C$^{18}$O at high temperature have been reported. Separately, a reliable approach for obtaining vibrational wave functions for most isotopologues has been proposed. These descriptions, based on the $SU_1(2)\times U(3)\times SU_2(2)$ dynamical group, provide spectroscopic-quality fits to vibrational term values with root-mean-square deviations of $0.06$ and $0.07~\mathrm{cm}^{-1}$, respectively. Using the resulting wave functions, we simulate the Raman spectra of both species by evaluating transition moments of the mean polarizability, represented as an expansion in curvilinear coordinates up to cubic terms within the same algebraic framework. The difference of two independent experimental Raman spectra under comparable temperature conditions is analyzed with the help of the simulations provided by our model. The resulting simulations show excellent agreement with experiment, reinforcing the reliability of the model, while the estimated transition moments are also consistent with experimental values.
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All authors Eduardo Suárez, Christian Ostertag-Henning, Miguel Carvajal, Renato Lemus
Strongly Correlated Electrons
Suppression of orbital ordering and emergence of a glassy magnetic state in a high-entropy spinel vanadate
Shun Ito, Sota Nakakuki, Satoshi Demura et al. (+1 more)
High-
entropy oxides provide a unique platform for exploring the interplay between configurational disorder and correlated electronic states. We report on structural, thermodynamic, and
magnetic properties of the high-
entropy spinel vanadate (Li$_{0.2}$Mg$_{0.2}$Mn$_{0.2}$Co$_{0.2}$Zn$_{0.2}$)V$_2$O$_4$, in which orbital-active V ions occupy the pyrochlore sublattice. X-ray diffraction measurements reveal that the cubic spinel structure is preserved at temperatures down to 5 K without any detectable
symmetry lowering. Unlike conventional spinel vanadates exhibiting a
symmetry-lowering structural transition driven by orbital ordering, the compound that we study exhibits a suppression of long-range orbital ordering in the high-
entropy state.
Magnetic susceptibility measurements show glassy
magnetic freezing at temperatures below $\sim$20 K, while specific-heat measurements reveal no anomaly associated with long-range ordering down to 3 K. Frequency-dependent ac susceptibility reveals pronounced glassy dynamics. Analyses based on the Mydosh parameter, dynamic scaling law, and Vogel–Fulcher law suggest an intermediate dynamical regime between canonical
spin-glass and cluster-glass behavior. Furthermore, Cole–Cole analyses reveal systematic deviations from a single Debye relaxation process, indicating the presence of heterogeneous
magnetic relaxation dynamics near the freezing regime. Our results demonstrate that, in a frustrated spinel vanadate, high configurational
entropy suppresses long-range orbital ordering and stabilizes a heterogeneous glassy
magnetic state, highlighting the combined roles of geometrical frustration, orbital degrees of freedom, and configurational disorder in high-
entropy magnets.
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All authors Shun Ito, Sota Nakakuki, Satoshi Demura, Tadataka Watanabe
Materials Science
Giant-exchange-driven Vectorial Control of a Minimal Topological Magnet in Eu3In2As4
Haonan Chen, Xunkai Duan, Guangyi Wang et al. (+13 more)
The interplay between magnetism and band
topology provides a route to controlling
quantum states of matter, yet its realization in materials is often constrained by weak exchange coupling and complex electronic structures. Here, a
giant exchange coupling is identified in the newly predicted topological magnet Eu3In2As4, giving rise to magnetization-dependent band shifts of up to 300 meV. Together with its intrinsically soft
magnetic response, this strong cou-pling enables systematic tuning of topological phases by both the magnitude and orientation of applied
magnetic fields. The magneto-topological phase diagram is mapped out in which an
antiferromagnetic topological
insulator ground state evolves, under modest fields, into a pro-posed intermediate 2/3-ferrimagnetic phase, and further into fully polarized
ferromagnetic states predicted to host either Weyl or nodal-ring semimetals. Notably, the Weyl phase corresponds to a minimal model hosting a single pair of Weyl nodes.
Quantum oscillations, anomalous
Hall transport and magneto-infrared spectroscopy consistently reveal exchange-driven band recon-struction across these transitions. Rotation of the magnetization theoretically provides an effi-cient means to tune the momentum-space positions and separations of the Weyl nodes. These results establish Eu3In2As4 as a model system for exploring how strong exchange coupling can be used to control topological band structures with minimal complexity.
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All authors Haonan Chen, Xunkai Duan, Guangyi Wang, Yuhan Du, Huayao Li, Jiayu Wang, Wenbin Wu, Zixuan Xu, Yingchao Xia, Jiaming Gu, Pengliang Leng, Lin Miao, Fengfeng Zhu, Xiang Yuan, Tong Zhou, Cheng Zhang
Mathematical Physics · Cross-listed from math.RA
Post-Poisson algebras, extended $\mathcal{O}$-operators and extended Poisson Yang-Baxter equations
Yuanchang Lin and Dilei Lu
This paper introduces the extended $\mathcal{O}$-operators on Poisson
algebras as a natural generalization of ordinary $\mathcal{O}$-operators, together with the extended Poisson Yang-Baxter equations. We show that $\mathcal{O}$-operators of weight $\lambda$ on Poisson
algebras give rise to post-Poisson
algebras, whose operad are the trisuccessor of the operad of Poisson
algebras, and that extended $\mathcal{O}$-operators induce new Poisson
algebra structures on module spaces.Equivalent characterizations of extended $\mathcal{O}$-operators are obtained via the symmetrizer-antisymmetrizer decomposition. The generalized Poisson Yang-Baxter equations are also introduced, and their connections with coboundary Poisson bialgebras and extended $\mathcal{O}$-operators are established. The tensor form of extended $\mathcal{O}$-operators leads to the notion of the extended Poisson Yang-Baxter equations, which generalizes the notion of the Poisson Yang-Baxter equations. Finally, the relationships among extended $\mathcal{O}$-operators, the extended Poisson Yang-Baxter equations, and the Poisson Yang-Baxter equations are studied in the framework of quadratic Poisson
algebras and semi-direct product Poisson
algebras.
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Physics and Society
Estimating GHG Emissions from AI Use: Framework for Corporate-Level Measurement
John Bistline, Shaena Ulissi, Steven J. Davis et al. (+5 more)
Electricity demand from data centers is expected to grow from roughly 5% of U.S. consumption in 2025 to between 9% and 17% by 2030, and corporate artificial intelligence (AI) use is following a similar trajectory, spanning employee productivity assistants, direct access to large
language models (LLMs), and AI features embedded in enterprise software. AI emissions today are a small share of footprints for many enterprises, but that share is unlikely to remain small for long. Without reasonable estimates, companies cannot set reduction targets or identify effective decarbonization levers as emissions grow. Companies, regulators, and auditors are asking for emissions estimates that withstand scrutiny, but no widely accepted methodology exists today. Published per-query estimates can differ by several orders of magnitude depending on what is counted, which provider is measured, and what assumptions are made about electricity use and the grid mix. This white paper proposes a standardized framework for corporate-level AI emissions accounting. The framework is designed to be defensible with current data constraints, tiered to meet companies where their data are, transparent about its assumptions, updatable as provider disclosure matures, and built for action rather than disclosure alone. Since AI emissions accounting is still nascent, it has the opportunity to design for actionability from the outset, so that measurement incentivizes responsible choices during AI's rapid buildout.
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All authors John Bistline, Shaena Ulissi, Steven J. Davis, Jonathan Glidden, James Joyce, Mo Li, Jackson Mohsenin, Sangwon Suh
Nuclear Theory
Anurag Tiwari and Min He
Non-perturbative scattering $T$-
matrix is a core input for the evaluation of transport phenomena in a strongly-coupled medium. Existing in-medium $T$-
matrix calculations are typically formulated in the two-particle center-of-mass frame, where the scattering equation can be reduced to a lower-dimensional problem. However, a medium explicitly breaks Lorentz invariance and defines a preferred reference frame, entailing that physical observables be constructed from scattering amplitudes evaluated in the medium rest (laboratory) frame. In this work, by exploiting the rotational
symmetry about the scattering-pair-momentum axis, we develop a practical framework for solving the in-medium two-body $T$-
matrix directly in the laboratory frame while retaining the full dependence on the total pair-momentum and scattering geometry. We demonstrate that the resulting amplitudes differ significantly from conventional center-of-mass-frame results and, when applied to heavy-light
quark scattering in the
quark-
gluon plasma (QGP), lead to 25-40% corrections to heavy-
quark drag coefficients at low momenta, thereby removing a significant source of theoretical uncertainty in extracting the QGP transport properties with heavy-
quark probes.
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Quantum Physics
Robust device-independent characterization of sharpness and incompatibility of unsharp instruments
Qian Zhang, Kai-Yu Yuan, Yan-Xin Rong et al. (+3 more)
Unsharp measurements are key resources for tasks that balance information gain and disturbance, but certifying them without device assumptions remains a challenge. We propose a fully device-independent protocol for characterizing unsharp instruments, based on an
entanglement-assisted sequential
quantum random access code, where the first decoder is allowed to communicate her measurement setting to the second. This communication-enhanced scheme creates a decoding regime in which both decoders surpass classical bounds, enabling tight quantification of sharpness and direct quantification of measurement incompatibility beyond noncommunicating protocols. Experimentally, we implement tunable unsharp measurements using a Mach-Zehnder interferometer, observing the predicted sequential enhancement in decoding probability. Additionally, we achieve significantly narrower sharpness intervals and incompatibility quantification across multiple target sharpness values. Our results show that communication is a powerful operational resource for certifying precisely unsharp instruments and advancing device-independent
quantum information protocols.
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All authors Qian Zhang, Kai-Yu Yuan, Yan-Xin Rong, Zhen Shang, Yong-Jian Gu, Ya Xiao
High Energy Astrophysical Phenomena
Evolution of low-mass He stars and implications for electron-capture supernova formation in close binaries
Jun-Qian Li, Ying Qin, Zi-Yuan Wang et al. (+3 more)
The
evolution of low-mass helium (He)
stars ($\sim2.5$–$5\,M_\odot$) with
neutron-
star (NS) companions in close binaries has been extensively studied, but the combined effects of rotation and
tidal interaction remain poorly understood. We investigate how rotation, mass transfer, and
tidal interactions affect the
evolution of low-mass He
stars, the formation of electron-capture
supernovae (ECSNe), and the properties of the resulting NSs. Using detailed
stellar and binary
evolution calculations that include mass loss, differential rotation, and
tidal interactions, we systematically explore the initial binary parameter space leading to ECSNe. We find that rotation has only a modest effect on the
evolution of low-mass He
stars. ECSNe occur within a narrow initial He-
star mass range of $2.42$–$2.67\,M_\odot$ at
solar metallicity ($Z_\odot$) and $2.37$–$2.62\,M_\odot$ at $0.01\,Z_\odot$. The resulting NSs have
spin periods of $7.7$–$83.8\,\mathrm{ms}$,
magnetic fields of order $10^{12}\,\mathrm{G}$, and rotational energies of $2.6\times10^{48}$–$2.5\times10^{50}\,\mathrm{erg}$, although these values would be substantially reduced if efficient angular-momentum transport mechanisms, such as the Spruit–Tayler dynamo, were included. We further show that the evolutionary outcome is highly sensitive to the initial orbital period, with shorter-period systems undergoing Roche-lobe overflow at earlier evolutionary stages and experiencing stronger binary interactions. Finally, comparison with
Galactic double NS systems indicates that most observed binaries can be reproduced in the eccentricity–orbital-period plane by adopting relatively large natal kick velocities.
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All authors Jun-Qian Li, Ying Qin, Zi-Yuan Wang, Qing-Wen Tang, Han-Feng Song, Georges Meynet
Quantum Physics
Sub-Vacuum Jamming for Secure Communication
Sh. Barzanjeh, A. Poostindouz and B. C. Sanders
Artificial-noise jamming improves physical-layer security by degrading an eavesdropper's channel, but the injected noise also interferes with the legitimate receiver. We introduce a correlated-jamming protocol based on classical and
quantum correlations that suppresses this self-interference while preserving the jamming penalty experienced by the eavesdropper. Bob broadcasts one mode of a correlated two-mode source and retains the second as a local reference. Eve, who has no access to the retained mode, receives the full thermal jamming field, whereas Bob uses an optimized joint measurement to cancel its correlated fluctuations. The residual self-jamming noise is governed by the conditional variance of the transmitted jamming quadrature given the retained reference. Any classically correlated source is bounded by the
vacuum-noise floor and therefore restores Bob, at best, to his unjammed receiver noise. An entangled two-mode squeezed source surpasses this limit and produces sub-
vacuum residual noise, with the maximum
quantum advantage set by the transmissivity of the jamming path back to Bob. In the bright-source regime, this advantage becomes a fixed reduction in Bob's noise floor, independent of the signal and jamming powers. Within a bounded-collection wiretap model, correlated jamming preserves positive secrecy even when Eve has a stronger direct channel than Bob and remains effective against collective measurements on Eve's Gaussian output states. The protocol supports bright classical message transmission and requires no end-to-end
quantum channel. Possible applications include shot-noise-limited optical communication, cryogenic microwave networks, and covert or power-constrained secure links.
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High Energy Astrophysical Phenomena
Radio Constraints on the Circumstellar Environment of the Type IIb Supernova SN 2024iss
Yuhei Iwata, Tomoki Matsuoka, Masanori Akimoto et al. (+6 more)
Type~IIb
supernovae exhibit diverse progenitor properties, and
radio observations offer a unique probe of their mass-loss histories shortly before the explosion. We present Japanese VLBI Network single-baseline monitoring of the nearby Type IIb SN 2024iss at 6.9 and 8.4 GHz, spanning approximately one year after its discovery. Our
radio observations have detected its emission at 10 and 23 days after the explosion, with subsequent epochs yielding non-detections. Based on the peak
radio luminosity and peak time, SN 2024iss exhibits
radio properties highly comparable to those of compact-envelope events. Using a synchrotron self-absorption (SSA) modeling, we estimate a progenitor mass-loss rate of $\dot{M} \approx 2.5 \times 10^{-6}\>M_{\odot}\>{\rm yr^{-1}}$ for a compact progenitor wind velocity of $100 \>{\rm km\>s^{-1}}$. Furthermore, our SSA analysis yields a mean expansion velocity of $V_{\rm sh} \approx 3.3 \times 10^4\>{\rm km\>s^{-1}}$, which exceeds the theoretical shock velocity derived from the self-similar solution by a factor of $\sim 2.4$. Even for the conservative upper-bound peak time, the SSA-derived velocity remains larger than the theoretical expectation by a factor of $\gtrsim 1.7$. To explain this velocity excess, we propose the presence of a confined, dense circumstellar matter (CSM) surrounding the progenitor. The shock emergence from this confined CSM may have accelerated the forward shock, pointing to a highly complex and non-steady mass-loss history shortly before the explosion.
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All authors Yuhei Iwata, Tomoki Matsuoka, Masanori Akimoto, Keiichi Maeda, Nozomu Tominaga, Yoshinori Yonekura, Takashi J. Moriya, Kotaro Niinuma, Kenta Fujisawa
Quantum Physics
Conditions for Quantum Advantage in AC Power Flow
Parikshit Pareek, Abhijith Jayakumar, Carleton Coffrin et al. (+1 more)
This paper aims to contextualize the requirements for
Quantum Computing (QC)
algorithms to achieve a
quantum advantage in solving the alternating current power flow (ACPF) problem, with a focus on runtime complexity. First, we establish a
benchmark for a QC iterative solver to demonstrate an advantage over the classical Newton-Raphson Load Flow (NRLF)
algorithm. Next, we derive a baseline expression for the end-to-end runtime complexity of any Gate-based QC
algorithm as $\Omega(N \kappa/\varepsilon),$ reflecting dependence on system size $N$, condition number $\kappa$, and error tolerance $\varepsilon$. Finally, we highlight key areas where QC
algorithms may offer potential benefits over NRLF in addressing the standard ACPF problem.
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All authors Parikshit Pareek, Abhijith Jayakumar, Carleton Coffrin, Sidhant Misra
Cosmology and Nongalactic Astrophysics
Say Hello, Wave Goodbye: Gravitational Waves from Hyperbolic PBH-SMBH Interactions
Laura Burn, Nelson Christensen and Richard Easther
Primordial black holes (PBHs) formed in the early Universe remain a viable dark matter candidate. Since dark matter is expected to be concentrated toward
galactic centres, a significant population of PBHs would reside near a supermassive black hole (SMBH), providing a promising environment for gravitational wave emission. We consider PBHs with masses from $10^{-15}$ to $10$
solar masses on
hyperbolic trajectories past an SMBH, that produce bursts of gravitational radiation during periastron passage. Sagittarius A* is an obvious location for these events, but we show that both M31* and M87* would generate similar signals, albeit at lower frequencies. We assess the detectability of both individual bursts and "popcorn" backgrounds, relative to LISA and the proposed $\mu$Ares mission. Comparing these results to plausible central
halo densities, we find that unbound PBHs are unlikely to yield detectable signals.
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Mesoscale and Nanoscale Physics
Electron Temperature and Electron-Electron Scattering Length in GaAs/AlGaAs Using Mesoscopic Multiparallel Aperture Geometries
Arati Thapa, Rishav Khatiwada, Prakash Sharma et al. (+5 more)
Quantifying electron temperatures and electron-electron scattering lengths is essential for understanding electron transport regimes in two-dimensional systems. To that end, this work experimentally investigates low-temperature ballistic transport using semiclassical cyclotron orbits in a multiparallel aperture geometry. The mesoscopic geometry is fabricated on a GaAs/AlGaAs
heterostructure of very high electron mobility. The amplitudes of maxima in magnetoresistance due to ballistic transport are observed to decay exponentially with temperature, allowing determination of the electron-electron scattering length from the data. A quantitative relation between electron temperature and an applied dc bias heating current is established by comparing magnetoresistance peak amplitudes measured as a function of temperature and dc bias, reflecting bias-induced Joule heating. In addition, the resistance measured near zero
magnetic field decreases with increasing temperature, providing signatures of superballistic conductance.
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All authors Arati Thapa, Rishav Khatiwada, Prakash Sharma, Jean J. Heremans, Adbhut Gupta, Kirk W. Baldwin, Loren N. Pfeiffer, Mansour Shayegan
Quantum Physics
Shor's algorithm requires Fanout
Lucas Gretta and Malvika Raj Joshi
Shor's
algorithm is a canonical
quantum supremacy target whose core operation relies on the
Quantum Fourier Transform (QFT). In this note, we resolve an open question of Fang, Fenner, Green, Homer and Zhang from 2006 by showing that approximating QFT in constant depth, for any $n$-
qubit modulus, necessarily requires the $n$-
qubit Fanout operation. Formally, let $\mathsf{QFT}_q$ be the gate acting on $n = \lceil \log q \rceil$
qubits that computes the QFT under modulus $q$. It is known that any $n$-
qubit $\mathsf{QFT}_q$ can be implemented in constant depth using $\mathsf{FANOUT}_n$, i.e. $\mathsf{QFT}_q \in \mathsf{QAC}^0_f$. We prove the converse by using a $\mathsf{QFT}_q$ gate to construct a state of "non-negligible felinity". Consequently, $\mathsf{QFT}_q \in \mathsf{QAC}^0 \iff \mathsf{FANOUT}_n \in \mathsf{QAC^0}$. In the case of $q = 2^n$, such as in Shor's, we approximate $\mathsf{FANOUT}_n$ using a single $\mathsf{QFT}_{2^n}$ gate and $O(1)$ two-
qubit local gates, thus tying the feasibility of realizing Shor's
algorithm with NISQ
circuits to that of Fanout.
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Materials Science
Universal Magnetoresistance Scaling in Layered Pd-based Multiband Metals Beyond Compensated Semimetal Regime
Kenjiro Okawa and Takao Sasagawa
We systematically investigated the magnetoresistance ratio (MR) of single-crystalline, nonmagnetic layered Pd-based metals, including centrosymmetric PdTe2, PdPb2, and beta-PdBi2 and noncentrosymmetric alpha-PdBi. Our study identifies a distinct class of large MR in multiband, high-carrier-density systems. Unlike well-studied extremely large MR materials, such as Dirac and Weyl semimetals described by simple compensated-carrier models, these compounds possess complex
Fermi surfaces, as validated by our first-principles calculations. Nevertheless, they exhibit a remarkably simple MR scaling governed by carrier mobility, manifested in systematic dependencies on
magnetic field, temperature, and the residual resistivity ratio (RRR). The validity of Kohler's rule in high-RRR
crystals indicates that MR is governed by a single effective scattering time, even in these multiband systems. The field and RRR dependences of MR follow an intermediate power-law behavior between linear and quadratic, attributable to imperfect carrier compensation and a distribution of carrier mobilities. Among the studied compounds, alpha-PdBi exhibits the largest MR, reaching 1500% (2 K, 7 T), owing to its exceptionally high RRR (approximately 660). However, when compared on an equal-RRR basis, its MR is smaller than that of its centrosymmetric counterparts. This trend suggests that additional scattering channels arising from
spin-orbit-induced band splitting in noncentrosymmetric systems reduce the effective carrier mobility. Our results establish a new class of large MR in clean multiband metals where complex electronic structures give rise to emergent single-parameter scaling, highlighting the interplay between disorder, mobility, and
symmetry.
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Chemical Physics
3D Molecular Representation Learning for Organic Mixtures: Viscosity and Density Prediction
Haicheng Qu, Yanyi Su, Ning Wang et al. (+4 more)
The viscosity and density of organic mixtures are essential properties for designing lubricants, solvents, and heat transfer fluids. In engineering practice, formulating a functional fluid requires understanding how these properties change with composition and temperature. However, exhaustive experimental characterization across the full parameter space is impractical due to the vast number of possible species and combinations. Here we introduce a mixture-aware 3D molecular representation learning strategy, built upon a pre-trained molecular encoder, that jointly encodes component structures, mole fractions, and temperature to achieve accurate predictions for organic mixtures. Fine-tuning on publicly available
datasets covering a wide range of binary organic mixtures yields test-set R2 values of 0.973 for dynamic viscosity and 0.996 for density, significantly outperforming traditional machine learning baselines. Beyond this overall accuracy, the model captures non-monotonic viscosity changes upon mixing, surpassing simple linear or logarithmic mixing rules. The architecture is extendable to ternary and multicomponent mixtures, as verified via preliminary experiments. Using this model, we quantitatively analyze how molecular structure-branching, cycloalkane, and aromatic rings-affects viscosity-temperature behavior, which benefits the design of lubricants with superior viscosity-temperature performance. Altogether, this work provides a practical, data-driven tool for mixture property prediction, accelerating the rational formulation of functional fluids in chemical engineering.
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All authors Haicheng Qu, Yanyi Su, Ning Wang, Shangqian Chen, Zhifeng Gao, Jun Cheng, Qi Ou
Optics
Geometric Control of Visible Emitter Creation in Hexagonal Boron Nitride by Oblique Ion Irradiation
Sagar Chowdhury, Bhaveshkumar Kamaliya, Ramachandra Bangari et al. (+5 more)
Ion irradiation creates optically active defects in wide-bandgap van der Waals materials, yet most approaches tune defect formation by varying the ion species, energy, or fluence while leaving the incidence geometry fixed. The ion-incidence angle is established here as a
geometric control parameter for engineering visible emitters in hexagonal boron nitride (hBN). The angle and ion fluence of a
plasma-focused heavy-ion (Xe+) beam are varied across hBN flakes of different thickness, and the resulting photoluminescence is quantified. In thick flakes, oblique irradiation shifts the fluence for maximum emission by nearly two orders of magnitude relative to normal incidence, whereas thin flakes exhibit an angle-independent optimum. Ion-trajectory simulations attribute this thickness dependence to lateral redistribution of the collision cascade and enhanced oblique sputtering. Atomic force microscopy identifies distinct processing regimes that delineate the useful defect-creation window. Post-irradiation annealing quenches the emission and shifts the spectral weight toward the green-yellow band while preserving the angle-dependent activation trends. Spectrally resolved lifetime measurements show comparable biexponential dynamics for normal and oblique incidence, consistent with emission from related defect families rather than a geometry-specific emitter species. These results establish ion-incidence geometry as a materials-level knob for programming optical defect activation and spatial defect distributions in van der Waals photonic materials.
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All authors Sagar Chowdhury, Bhaveshkumar Kamaliya, Ramachandra Bangari, Caleb Whittier, Joseph Spielbauer, Nabil D. Bassim, Thomas G. Folland, Ravitej Uppu
Quantum Physics
High-Performance Quantum Transduction with Correlated Noise
Yu-Bo Hou, Xiaoan Ai, Pengbo Li et al. (+1 more)
Quantum transduction, which coherently converts
quantum states between microwave and optical frequency domains, is a key technology for hybrid
quantum architectures. Its performance, however, is fundamentally limited by thermal noise. Direct
quantum transduction is particularly susceptible to noise and often fails to achieve positive
quantum capacity.
Entanglement-based
quantum transduction, which realizes state conversion through
quantum teleportation assisted by microwave-optical
entanglement, is intrinsically more robust against thermal noise. However, generating sufficiently strong
entanglement in a realistic thermal environment remains a major challenge. In this paper, we exploit correlated noise as a resource for
quantum transduction. For direct
quantum transduction, it is shown that the noise correlations give rise to controllable interference terms that substantially suppress the effective channel noise. For
entanglement-based
quantum transduction, the same correlations enhance the generation of microwave-optical
entanglement, thereby improving the fidelity of teleportation-based conversion. As a result, both transduction protocols exhibit broad regions of positive
quantum capacity over experimentally relevant ranges of cooperativity. We further discuss a possible physical mechanism for engineering the required noise correlations, providing theoretical guidance for experimental implementations. These results suggest that correlated noise can substantially relax the stringent cryogenic requirements for microwave-optical
quantum transduction and facilitate the realization of practical hybrid
quantum networks.
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All authors Yu-Bo Hou, Xiaoan Ai, Pengbo Li, Changchun Zhong