Quantum Physics
Holonomic quantum gates via continuous measurement in bosonic codes: GKP and cat states
Juan Garcia-Nila, Anirudh Lanka and Todd A. Brun
We apply continuous measurement-based holonomic
quantum computation (CMHQC) to bosonic
quantum error-correcting codes and develop explicit protocols for both four-component cat codes and Gottesman-Kitaev-Preskill (GKP) codes. In this framework, a continuously monitored time-dependent codespace undergoes a closed trajectory on the Grassmannian
manifold while Zeno confinement suppresses departures from the instantaneous code subspace. For cat codes, we construct a family of squeezed-cat trajectories whose projected Wilczek-Zee connection generates arbitrary logical Z rotations, including non-Clifford T-gates. For GKP codes, we introduce a translated-
lattice trajectory that realizes the logical GKP T gate through a purely
geometric holonomy. We derive the corresponding time-dependent projectors, analytically evaluate the projected connections, and show that the resulting holonomies reproduce the desired logical operations without
Hamiltonian control. Furthermore, we analyze the error-correcting capabilities of the instantaneous codespaces by establishing dressed Knill-Laflamme conditions for the relevant bosonic error models and derive analytical estimates for leakage induced by finite-strength continuous measurements. Our results provide a concrete realization of measurement-induced holonomic control in experimentally relevant bosonic platforms and establish a full fault-tolerant logical gate implementation.
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Materials Science
Strain-controlled magnetism and magnetoelasticity in monolayer NiPS$_3$ and CrPS$_4$
Balázs Nagyfalusi, Alvaro Bermejillo-Seco, Linde de Jong et al. (+5 more)
We develop a first-principles framework for magnetoelastic coupling in two-dimensional magnets based on a strain-dependent Heisenberg model. In this approach, strain derivatives of the exchange interactions provide direct access to magnetostriction and to the
magnetic renormalization of the elastic tensor, establishing a microscopic link between
spin interactions and elastic response. We apply the method to monolayer NiPS$_3$ and CrPS$_4$, which exhibit contrasting magnetoelastic behavior. NiPS$_3$ shows weak and nearly isotropic
spin-
lattice coupling, consistent with a robust zigzag
antiferromagnetic ground state. In contrast, CrPS$_4$ displays strong anisotropic coupling, leading to strain-driven transitions between
spin-spiral and
ferromagnetic phases and significant changes in the critical temperature and elastic response. Our results demonstrate a general route to quantify magnetoelastic effects in low-dimensional magnets and highlight CrPS$_4$ as a promising platform for strain engineering of
magnetic order.
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All authors Balázs Nagyfalusi, Alvaro Bermejillo-Seco, Linde de Jong, Ritesh Das, Yaroslav M. Blanter, Herre S. J. van der Zant, Amador Garcia-Fuente, and Jaime Ferrer
Nuclear Theory
Nuclear level density studied in odd-mass nuclei in the framework of the projected shell model
Jiaqi Wang, Saumi Dutta, Cui-Juan Lv et al. (+2 more)
In a recent article [Phys. Rev. C 108, 034309 (2023)], we proposed a projected shell model method for the calculation of
nuclear level density (NLD) in deformed even-even
nuclei. The current article presents the subsequent study of NLDs in odd-mass
nuclei as well as a comparative analysis between our calculated NLDs in adjacent even-even and odd-A systems. Since one nucleon in the odd-mass system remains blocked from participating in the pair formation, resulting in a weakened pairing (assessed by a smaller BCS pairing gap), pronounced differences between the NLDs in an odd-mass (both even-odd and odd-even)
nucleus and its immediate even-even neighbour have been found. In general, the structure-dominated variations, which were found to be prominent in the even-even NLD at low energies, are greatly suppressed in the odd-mass systems. Specifically, from excitation energy as low as 2 MeV, the calculated densities of odd-parity and even-parity levels in odd-mass
nuclei show an equal division signaling faster attainment of the statistical behavior.
Nuclear level-
spin distributions of both parities have been seen to adopt a regular Gaussian shape earlier than that found in the even-even system. Moreover, the pleasant property of our shell-model results, that each of our calculated levels is an eigenstate of angular momentum, allows us to extract the values of the energy-dependent dispersion $\sigma$ of Ericson's
spin-distribution formula and plot $\rho(E, I, \pi)$, the energy-,
spin-, and parity-dependent level density.
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All authors Jiaqi Wang, Saumi Dutta, Cui-Juan Lv, Long-Jun Wang, Yang Sun
Statistical Mechanics
Observable dependence and rate identifiability in false-vacuum decay of the quantum Ising chain
Boliang Yu, Ruixin Zhou and Hang Su
Extracting a thermodynamic nucleation rate from finite-time
quantum dynamics requires separating observable decay from
estimator and finite-size validity. We develop a multilevel identification framework for real-time tensor-network simulations of false-
vacuum decay in the one-dimensional
quantum Ising chain. Across twelve parameter points, the same coherent two-kink amplitudes semi-quantitatively predict both infinite-chain survival and magnetization dynamics: the survival coefficient has a median
lattice-to-theory ratio of 0.896, while the magnetization-area slope ratios span 0.767–0.931. By contrast, the microscopic nearest-neighbour bond response is coherence dominated:
vacuum–pair coherence contributes 60.0–81.5% across seven points with matched bond-dimension control, while substantial late-window slope discrepancies remain that cannot be removed by a scalar normalization. The analysis establishes finite-time survival and magnetization
benchmarks and identifies the additional finite-size and branch-validation requirements for a bulk thermodynamic rate interpretation. Within the two-kink model and under the adopted common normalization, the
lattice-resolved WKB action gives a median fixed-prefactor rate discrepancy of 4.13% from the coherent-bubble spectral calculation. These results distinguish finite-time
lattice–theory consistency from the additional observable and finite-size evidence required to identify a thermodynamic nucleation rate.
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Astrophysics of Galaxies
From blue to red spirals: Slow galaxy transformation via ram pressure stripping in TNG-50
V. Lora, J. I. Gonzalez-Carbajal, A. Pasquali et al. (+5 more)
Late-type
galaxies lose gas through ram-pressure stripping (RPS) after falling into a massive
halo. Because this mechanism primarily removes the gaseous component while leaving the
stellar disk largely undisturbed, it provides a pathway for quenching
star formation without immediate morphological transformation. While RPS is well established in
galaxy clusters,
galaxy evolution in low-mass groups is often attributed to mergers, leaving open the question of whether RPS alone can drive the transition from blue,
star-forming spirals to quenched systems in these environments. We use the high-resolution cosmological simulation TNG-50 to investigate the
evolution of blue spiral
galaxies, after their infall into group-scale
halos. We excluded systems undergoing significant mergers, thus isolating the effect of RPS. We find that RPS in low-mass groups (M$_{group}<10^{14.5}$ M$_{\odot}$) can efficiently quench
star formation while preserving the
stellar disk structure. The transformation is gradual, with quenching timescales $\gtrsim6$ Gyr after infall, longer than the $\sim4$ Gyr typically associated with merger-driven
evolution. The resulting
galaxies are predominantly red, anemic spirals rather than fully transformed S0 systems, indicating that gas removal alone is insufficient to produce complete morphological transformation. Our results show that RPS in group environments can generate long-lived quenched spirals which might represent an intermediate evolutionary pathway preceding the formation of lenticular
galaxies.
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All authors V. Lora, J. I. Gonzalez-Carbajal, A. Pasquali, A. Marasco, J. Fritz, E. K. Grebel, J. P. Ortiz-Jimenez, S. Estrada-Dorado
Earth and Planetary Astrophysics
Spectral Energy Distribution Analysis for Habitable Worlds Observatory Target Stars
Stephen R. Kane, Kaspar von Braun, Tara Fetherolf et al. (+1 more)
The Habitable Worlds Observatory (HWO) will directly image and characterize
planets potentially similar to Earth orbiting nearby
stars. Accurate
stellar properties, particularly effective temperatures ($T_\mathrm{eff}$), angular diameters ($\theta_\star$), and bolometric fluxes ($F_\mathrm{bol}$), are essential for reliable Habitable Zone (HZ) calculations,
exoplanet yield predictions, and coronagraph design trade studies. We present a spectral energy distribution (SED) analysis for the 164
stars from the HWO
Exoplanet Exploration Program (ExEP) list, using $\chi^2$-minimization fits of empirical spectral templates from the Pickles
stellar spectral flux library to broadband photometric data. The SED fits provide direct measurements of $F_\mathrm{bol}$. We adopt spectroscopic $T_\mathrm{eff}$ values from the PASTEL catalog for 127 of the 164
stars, with the remainder drawn from the HWO ExEP catalog, and use these in combination with $F_\mathrm{bol}$ to calculate $\theta_\star$ via the Stefan-Boltzmann equation. As a consistency check, we compare the Pickles template $T_\mathrm{eff}$ with the adopted spectroscopic values and find agreement to within $\sim$3% for 65% of the sample, with a systematic tendency for the templates to yield cooler values. We identify 48
stars with discrepancies exceeding 200~K, including close binary systems where photometric contamination compromises the SED solution. We discuss the implications for HZ boundary calculations, atmospheric
retrieval of directly imaged
planets, and target prioritization for HWO. This SED catalog constitutes a uniform set of empirically determined $F_\mathrm{bol}$ values and associated
stellar parameters for the HWO target sample.
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All authors Stephen R. Kane, Kaspar von Braun, Tara Fetherolf, Natalie R. Hinkel
Superconductivity
Light induced superconducting diode effect in patterned films
Evan M. Wilson, Hou-Tong Chen and Alexander V. Balatsky
Structured light offers a route to control superconducting transport without permanently modifying the material or applying a static bias. Here we show that structured optical driving can generate a superconducting diode response in patterned superconducting films with asymmetric holes. Using generalized time-dependent Ginzburg Landau simulations, we find that optical driving produces rectified dc photovoltages and zero bias directional supercurrent imbalance in a junction free geometry, with continuous-drive diode efficiencies of order $10^{-3}$ and pulsed efficiencies reaching $10^{-2}$. The response is controlled by both the hole array and the optical mode. Increasing the number of asymmetric holes enhances rectification, reversing circular helicity reverses the diode polarity, and the optical spatial mode strongly modifies the magnitude and polarity of the directional response. Pulsed excitation enhances the zero bias line cut current imbalance to the percent level. For linearly polarized illumination, the asymmetric metacrystal converts the drive into local
chiral supercurrent motion, inducing an inverse Faraday effect like mechanism for dynamical time reversal
symmetry breaking. These results establish patterned superconducting films as a viable platform for light-tunable superconducting diode behavior.
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Quantum Physics
Robust Quantum Machine Learning for Collider Event Selection under Detector Variability
Christopher Brown, Michael Spannowsky and Simon Williams
Robust machine-learning methods are becoming increasingly important for high-energy physics data analysis as experiments enter the era of higher luminosity and future higher-energy
colliders. Detector degradation, changing running conditions and calibration drift can shift data distributions, causing models trained on clean reference samples to degrade after deployment. We investigate whether parameterised
quantum models provide a useful inductive bias for robust
collider-event selection in two complementary settings. In the unsupervised study,
quantum autoencoders trained on background events are compared with classical and variational autoencoders for anomaly detection. In the supervised study,
quantum classifiers with data reuploading are trained to distinguish a supersymmetric signal from background and are compared with linear and multilayer-perceptron classifiers. All models are trained under reference conditions and subsequently evaluated under controlled feature-level smearing while their parameters and preprocessing transformations are held fixed. On clean inputs, the
quantum autoencoders achieve competitive anomaly-detection performance, including in the low-false-positive-rate regime relevant for triggering, while the deeper data-reuploading classifier attains discrimination comparable to the non-linear classical baseline. Under smearing, the
quantum models generally exhibit smaller shifts in their output scores and retain their discrimination more effectively than the expressive classical baselines. These results suggest that parameterised
quantum models can provide a useful robustness inductive bias for
collider-event selection and motivate further studies with realistic detector systematics, finite-shot statistics and
quantum-device noise.
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Earth and Planetary Astrophysics
A Pair of Warm Saturn-mass Planets near the 2:1 Mean Motion Resonance around TOI-3850
Sean Collins, Michelle Kunimoto, Nicolas B. Cowan et al. (+24 more)
Warm Jupiters, with orbital periods of $10$–$200~\rm{days}$ and radii exceeding $8~R_{\oplus}$, are a relatively understudied class of
exoplanets occupying the parameter space between hot Jupiters and more widely separated, colder Jupiter analogs. In this work, we report the detection of a multi-
planet warm Jupiter system around TOI-3850 (TIC-143008050), a moderately active, near-
solar metallicity G0
dwarf star observed by TESS in Sectors 15, 21, 41, 48 and 75. Initially, a single candidate
planet was discovered by TESS, displaying transit timing variations (TTVs) with an amplitude of $\sim 1~\rm hr$ and a super-period of $513~\rm days$. Through a combination of transit photometry, radial velocity observations with MAROON-X, and TTV modeling, we identify two
planets: TOI-3850 b $(P_b=14.484\pm0.002~\mathrm{days},~ M_b =112\pm20~M_{\oplus},~e_b = 0.018\pm0.008, R_b = 12.07\pm0.09~R_{\oplus}, ~T_{\rm{eq}}=841\pm10~\rm{K})$, a transiting warm Jupiter, and TOI-3850 c $(P_c=29.85\pm0.01~\mathrm{days},~ M_c =90\pm15~M_{\oplus},~e_c < 0.015, ~T_{\rm{eq}}=661\pm7~\rm{K})$, a non-transiting, Saturn-mass companion. The two
planets lie wide of the 2:1 mean motion resonance $(P_c/P_b \approx 2.06)$, consistent with a formation history involving disk-driven migration. $N$-body integrations indicate that TOI-3850 c may begin to transit on decadal timescales, while TOI-3850 b remains a promising target for follow-up atmospheric characterization.
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All authors Sean Collins, Michelle Kunimoto, Nicolas B. Cowan, Keivan G. Stassun, Jack J. Lissauer, Ze'ev Vladimir, Teo Močnik, Ernesto Elenter, David W. Latham, Karen A. Collins, Jacob Bean, Stephanie Striegel, Khalid Barkaoui, Ritvik Basant, Tanya Das, Raquel Forés-Toribio, Akihiko Fukui, Jose A. Muñoz, Felipe Murgas, Enric Palle, Ivan A. Strakhov, Richard P. Schwarz, Avi Shporer, Gregor Srdoc, Chris Stockdale, Neil B. Thomas, Francis P. Wilkin
Quantum Physics
Modelling quantum measurement dynamics: from decoherence to redundancy with site-hopping indistinguishable particles
Katja Schneeweiss, Tom Rivlin, Maximilian P. E. Lock et al. (+2 more)
In recent years, new theoretical insights into decoherence and
quantum measurements have emerged through the study of many-body dynamics in isolated
quantum systems. It is now understood that the parameters and energy scales in system-environment interactions decisively affect how readily information spreads from a
quantum system into its surroundings during a decoherence event. A popular choice for studying these effects is the framework of
quantum Darwinism (QD), but so far few works have applied this to realistic many-body models. Inspired by experimentally-accessible setups, in this work we introduce a simple, flexible, numerically exact many-body model of a system broadcasting information into an environment: a 1D
lattice of sites with hopping particles. We show that different choices of parameters lead to the recovery of known scenarios featuring different decoherence and QD effects, such as equilibration, revivals of coherence, and redundancy. In constructing this model we resolve the crucial issue of indistinguishability: we explain how to calculate the
entropy of a fraction of the environment when said environment is composed of indistinguishable
fermions or
bosons (or
lattice sites containing them). We then show that particle statistics can make a notable difference to the QD properties of the setup, with fermionic environments sometimes achieving redundancy much more readily than bosonic or site-based ones. Our work opens the door to much closer
alignment between theoretical models and experimental tests of the dynamics of
quantum measurements and the
quantum-to-classical transition.
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All authors Katja Schneeweiss, Tom Rivlin, Maximilian P. E. Lock, Marcus Huber, Iva Březinová
High Energy Physics (Phenomenology)
Particle Production, Equilibration, and Quantum Recurrences from Classical Fields
Iván Cuntín, Wenyang Qian and Bin Wu
We investigate particle production from classical fields, a phenomenon central to the pre-
equilibrium dynamics of relativistic heavy-ion collisions and the reheating epoch of the early Universe. Using
lattice $\lambda\phi^4$ theory as a proof of principle, we show that this problem is naturally amenable to
quantum computation, providing a first-principles framework for nonequilibrium
quantum-field dynamics beyond existing approximations. We perform simulations on small spatial
lattices, exhausting our available classical computational resources while maintaining a direct mapping to future
quantum-computing implementations. We find that particle production is accompanied by equilibration of observables, including the field expectation value, occupation-number distribution, and pressure. The observed equilibration persists for timescales several times longer than the initial equilibration time before the observables resume oscillatory behavior associated with
quantum Poincaré recurrences. Our results establish a route toward first-principles studies of equilibration in nonequilibrium
quantum field theory and provide insight into the search for the smallest possible locally equilibrated
quark-
gluon systems at
hadron colliders.
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High Energy Astrophysical Phenomena
XRISM Spectroscopy of Variable Accretion-driven Disk Winds in NGC 4151: When, Where, and How Fast Outflows are Launched
Xin Xiang, Jon Miller, Missagh Mehdipour et al. (+12 more)
X-ray observations probe the inner
accretion flow within active
galactic nuclei, revealing the highest gas column densities and fastest winds. The most diverse winds yet revealed with the Resolve calorimeter spectrometer aboard XRISM are found in NGC~4151, a nearby Seyfert-1 AGN that may qualify as a “changing-look” source (CLAGN). Herein, we report on wind variability in 14 XRISM observations of NGC~4151, summing to 0.9~Ms of exposure over a period of 395 days. We examined the dependence of key wind parameters on hardness and intensity selections, and as a function of time relative to flaring and dip events. The results suggest a globally organized but locally complex wind structure. Slow “warm absorber” components (WAs; $v_{\rm{out}} \sim 100-1000~\rm{km~s^{-1}}$) are always observed and likely represent failed winds at radius of $10^4 - 10^5 GM/c^2$, within the inner wall of the
torus. In contrast, “very fast” and “ultra-fast”
outflows (VFOs and UFOs; $v_{\rm{out}} \sim 10^3-10^4~\rm{km~s^{-1}}$, $v_{\rm{out}} \sim 0.033-0.33~c$) are strongest 10~ks after the peak of
flares, and during periods with low flux. Ten kiloseconds is among the shortest
flare–wind response timescales reported in an AGN, suggesting that the winds are observed close to the launching site. The absorption measure distribution (AMD) and the large
outflow momentum rates suggest that the high-velocity flows visible in the Fe~K band are magnetically driven, while locally clumpy, likely owing to radiation pressure; one or both of these mechanisms may be enhanced following a
flare and most visible during low-flux windows.
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All authors Xin Xiang, Jon Miller, Missagh Mehdipour, Ehud Behar, W. Niel Brandt, Laura Brenneman, Luigi Gallo, Elias Kammoun, Peter Kosec, Liyi Gu, Doyee Byun, Richard Mushotzky, Stephane Paltani, Elisa Costantini, Abderahmen Zoghbi
Quantum Physics
Teleportation through time-varying channels: threshold geometry and a complete-positivity bound on non-Markovian backflow
Chaibata Seida
A Bell pair distributed through a link that combines amplitude damping with dephasing at time-dependent rates has dynamics that separate into a fixed part and a moving one. The negativity, fully entangled fraction, discord, and average teleportation fidelity depend on time only through the accumulated damping parameters $p(t)$ and $q(t)$. Every threshold is therefore a curve fixed in the unit square, and the rates select nothing but a trajectory across it. The Horodecki fidelity formula $\bar{F} = \frac{1}{2} + \frac{1}{6}\mathrm{Tr}|T|$ covers one- and two-sided exposure alike: the condition $\det T \leq 0$ under which it takes this form holds throughout the unit square for both. Under symmetric two-sided noise the
entanglement vanishes when $p+q\geq1$, where the exact relation $\bar{F}^{2s}=\frac{2}{3}+\frac{1}{3}\mathcal{N}_{2s}$ ties disentanglement and the loss of
quantum advantage to the same instant. One-sided exposure admits no finite-time sudden death for any rate profile, and the discord stays strictly positive throughout the open square, so the distributed state can be separable, useless for teleportation, and still nonclassical. For harmonically modulated rates, complete positivity caps the backflow at one modulation period of static decay, $\Delta\Gamma_{k}\leq2\pi\gamma_{k,0}/\Omega$, equivalently at a modulation depth $\xi_{k}\leq4.6033$ independent of $\Omega$. Inside that window the trajectory reverses, producing finite intervals of restored
quantum advantage and
entanglement sudden birth.
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High Energy Physics (Theory)
Exact Defect Correlation Functions in Chern-Simons Matter Theories
Gwenaël Ferrando and Elior Urisman
We study defect correlators in three-dimensional, large-$N$, conformal field theories with slightly broken higher-
spin symmetry. Focusing on the quasi-fermionic theory, we bootstrap correlation functions of four defect-changing operators, i.e. of two collinear conformal line defects with boundaries, at arbitrary values of the coupling constant. We can compute an infinite number of such correlators and present a detailed analysis for three typical cases. In addition, we obtain some defect OPE coefficients that give us access to the relative conformal dimension between defect-changing operators at order $O(1/N)$. In the course of our analysis, we also derive explicit expressions for some Feynman integrals that might be of independent interest, including an extension of the usual
star-triangle relation. Our bootstrap assumptions naturally apply to Chern-Simons matter theories, so our results provide a non-trivial example of explicit, non-perturbative defect four-point functions in a strongly coupled gauge theory.
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Earth and Planetary Astrophysics
Formation of multiple dust rings and gaps in protoplanetary discs by a single migrating planet. A parameter study in locally isothermal discs
Sören C. Meiners, Kim M. Weiskopf, Thomas Rometsch et al. (+1 more)
ALMA observations show that large protoplanetary discs usually contain multiple concentric
dust rings separated by dark gaps. A natural explanation is
dust-trapping at the edges of gaps opened by newly formed
planets. However,
planets typically migrate inward on timescales shorter than disc lifetimes, seemingly at odds with rings at large radii. We aim to investigate the conditions under which migrating
planets can form long-lived, multi-ringed structures out to $r\sim 150$ au to constrain the parameter space for the planetary origin hypothesis of rings. Using the FargoCPT hydrodynamics code, we ran two-dimensional, locally isothermal disc models with a single migrating
planet, varying disc aspect ratio, viscosity ($\alpha$), and planetary mass. In all models, the
planet eventually stalls in a deep gap. At $\alpha\leq 10^{-4}$, secondary spirals launched by the
planet can open additional gaps at smaller radii. When
planets exceed twice the local thermal mass before stalling, they enter a regime of alternating slow and type-III rapid migration, leaving partial gaps outside their orbit. The gap edges consistently feature pressure maxima that trap
dust. These begin as large
vortices at $\alpha\leq 10^{-4}$, but gradually smear out into rings before dissipating. The type-III remnant rings dissipate quickly at $\alpha=10^{-3}$, but persist for at least 300-500 kyr at $\alpha\leq 10^{-4}$. Both smear-out and dissipation timescales increase with lower $\alpha$. Our results show that migrating
planets can reproduce observed multi-ringed structures in discs with $\alpha\lesssim 10^{-4}$ through their stall ($r\lesssim 50$ au), secondary gap-opening ($r\lesssim 20$ au), and type-III migration remnants (extending to $r\sim 150$ au for Jupiter-mass
planets in sufficiently massive discs). Longer simulations will be required to compare the statistics of ring-to-
vortex occurrence to observations.
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All authors Sören C. Meiners, Kim M. Weiskopf, Thomas Rometsch, Cornelis P. Dullemond
High Energy Astrophysical Phenomena
A Diverse Distribution of Black Hole Spins from Stable Mass Transfer
Linhao Ma, Jakub Klencki, Eliot Quataert et al. (+1 more)
Gravitational wave observations have found over 300 merging binary black holes, yet their origins remain uncertain. Recent work showed that many may come from isolated
stellar binaries whose orbits shrink through stable mass transfer. If true, their
spins may help to distinguish this channel from other formation pathways. We investigate the
tidal spin up of black hole progenitor
stars with detailed modeling of binaries undergoing stable mass transfer. We calculate the
tidal torques by solving tidally excited oscillation modes and predict the resulting black hole
spins. We find a diverse
spin distribution strongly affected by the mass transfer histories of the progenitors. Binaries can form black holes with moderate
spins ($0.1\lesssim\chi_\mathrm{eff}\lesssim0.3$) if they only go through case A or case B mass transfer. In the former case, they can become super-synchronized upon detachment, while in the latter case, the donor is usually only partially stripped, leaving a puffy envelope where strong tides are excited. If both case A and case AB mass transfer occur, the resulting black hole
spins are almost always negligible. As the mass transfer history is jointly determined by mass ratio and initial binary period, our results predict an anti-correlation between black hole
spins and mass ratio, consistent with limited evidence from data. Our results can also potentially explain the case of GW190412, a moderately-spinning binary with a high mass ratio. We discuss the limitations of our methods and additional physics (e.g., nonlinear tides, case C, and L2 mass transfer) that need to be incorporated in future work.
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All authors Linhao Ma, Jakub Klencki, Eliot Quataert, Lieke van Son
Quantum Physics
Marcin Rudziński, Aaron Z. Goldberg, Andrei B. Klimov et al. (+2 more)
Coherent states bridge the gap between
quantum and classical physics, but their overcomplete and nonorthogonal nature makes it difficult to identify the minimal discrete set needed to reconstruct
quantum information. Finite
spin-coherent
tomography and discrete coherent-state operator bases are known, but here we address the more specific rank-resolved problem of preserving the canonical contravariant-symbol representation. We show that the canonical finite coherent-state formula reconstructs every operator in the rank-$S$ sector exactly if and only if the sampling points form a spherical $(2J+S)$-design. We call the associated configurations
spin-coherent
quantum designs. We further give a fully explicit positive-weight Gauss-Legendre construction that avoids the need for an equal-weight spherical design. Together, these results establish a unified framework for reading out physical observables from a handful of measurement samples, playing for
spin systems the role that the so-called von Neumann
lattice plays for canonical coherent states. Finally, we derive practical protocols for estimating moments of
spin operators from these constructions, with direct applications to polarimetry, magnetometry, and
quantum state
tomography.
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All authors Marcin Rudziński, Aaron Z. Goldberg, Andrei B. Klimov, Luis L. Sánchez-Soto, Karol Życzkowski
Quantum Physics
Spectrally local geometric response at the onset of many-body quantum chaos
George Mihailescu and Pablo M. Poggi
We introduce the spectral density of
geometric response, a measure of eigenstate sensitivity across an energy spectrum. Applied to many-body
quantum systems, it reveals an exponentially sensitive integrability-to-chaos crossover, where eigenbasis deformations first accumulate in localized spectral regions before spreading throughout the spectrum. Physically motivated random-
matrix ensembles reproduce this behaviour, whereas Gaussian ensembles do not, indicating universal features of the route to chaos that are absent from featureless random-
matrix models.
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High Energy Physics (Theory)
A Comment On Topological Degeneracy In Gauged WZW Models
Gregory W. Moore, Eliezer Rabinovici and Ranveer Kumar Singh
Given a Lie group $G$, a level $k$, and a Lie subgroup $H$ one can construct 2d conformal field theories by either 1.) gauging a nonanomalous $H$
symmetry of the WZW model constructed from $(G,k)$ or 2.) using an algebraic procedure known as the GKO coset construction. The two models are closely related, but not precisely the same: The gauged WZW model is identified with the corresponding GKO model coupled to a 2d topological field theory. The topological theory is characterized by a commutative Frobenius
algebra derived from the endomorphisms of an
algebra object in a modular tensor category constructed from $(G,H,k)$. The partition function on the
torus of the two models differ by a factor of the dimension of this
algebra of endomorphisms. Concrete examples are constructed and some applications to string theory and 2d Yang-Mills coupled to nonanomalous matter are briefly discussed. This paper is a summary of a longer companion paper.
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High Energy Physics (Theory)
Universal quadratic field equations via homotopy algebras
Christoph Chiaffrino, Raji Ashenafi Mamade and Barton Zwiebach
We explain how the 'bar-cobar' construction for homotopy
algebras reformulates the equations of motion of arbitrary gauge theories as gauge-covariant quadratic equations for an extended set of fields. The linear term of the new equations encodes the interactions of the original theory, while the quadratic term is universal. The extended fields include type-I multilocal fields, which depend on a set of coordinates and type-II multilocal fields, which depend on several sets of coordinates. The new equations of motion are the Maurer-Cartan equations of a differential graded associative
algebra or Lie
algebra. We show that every solution of the new equations is gauge equivalent to a solution with only type-I fields, that represents a solution of the original equations of motion. In string theory type-I fields are entangled states of the associated CFT, to be inserted across multiple punctures of a Riemann surface. General type-II states can also represent disconnected Riemann surfaces.
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High Energy Physics (Phenomenology)
Effective Lagrangians from functional matching
Stefan Dittmaier, Sebastian Schuhmacher and Maximilian Stahlhofen
We briefly review a variant of functional matching to derive an Effective Field Theory (EFT) for heavy particles at the one-loop level in the top-down approach. The method integrates out heavy fields that correspond to mass eigenstates, i.e. after removing mixing effects by diagonalizing mass
matrices. Tree- and loop-level effects are separated by employing the background-field method, hard and soft modes are separated with the use of the expansion by regions. The method is exemplified for the
Higgs Singlet Extension of the Standard Model where the mass $M_\mathrm{H}$ of the additional
Higgs boson is considered large, and the
Higgs mixing angle $\alpha$ is assumed to scale like $1/M_\mathrm{H}$, in order to guarantee decoupling in the large-$M_\mathrm{H}$ limit. Our calculation is agnostic w.r.t. the type (SMEFT vs. HEFT) of the emerging EFT. Eventually the emerging EFT Lagrangian can be transformed into SMEFT form, but only at the cost of introducing fermionic EFT operators, although no such operators are directly generated upon solving the functional integral over the heavy
Higgs field.
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Strongly Correlated Electrons
Thermodynamic Spectroscopy of Emergent Excitations in Quantum Spin Ice
Zhengbang Zhou, Tony An and Yong Baek Kim
Quantum spin ice (QSI) is a three-dimensional
quantum spin liquid where fractionalized spinons interact with emergent
photons. The XXZ model on the pyrochlore
lattice realizes such a $U(1)$
quantum spin liquid and a number of pyrochlore magnets have been investigated as candidate materials, but the detection of emergent excitations has been a major challenge. The specific heat is expected to show the higher-energy spinon excitations and a lower-energy anomaly at the ring-exchange scale, which sets both the
photon bandwidth and the energy of the emergent
magnetic monopoles (or visons). In reality, the lower-energy peak is obscured by the
nuclear Schottky anomaly in non-Kramers Pr-based systems, while it is not clearly resolved from the spinon contributions in Ce-based dipolar-octupolar systems. In this work, we propose a novel thermodynamic probe of the elusive ring-exchange energy scale. We show that in the presence of a weak perturbation coupled to the transverse component of the pseudospin degrees of freedom, the temperature derivative of an observable conjugate to such a weak perturbing force is highly sensitive to the ring-exchange energy scale. Using this scheme, it is shown that the difference between thermal expansion coefficients along the [100] and [010] directions should show a peak at the ring-exchange energy scale for non-Kramers QSI. Similarly, the temperature derivative of the magnetization, $dM/dT$, of dipolar-octupolar pyrochlores under a weak
magnetic field can also detect the same signal. Moreover, the sign of these signatures distinguishes the zero-flux and $\pi$-flux QSI states.
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Instrumentation and Detectors
Temperature-Dependent Performance of NaI(Tl) Crystal with Dual-Channel SiPM Readout for Low-Mass Dark Matter Searches
W. K. Kim, H. Y. Lee, K. W. Kim et al. (+1 more)
We report the first temperature-dependent characterization of a NaI(Tl)
crystal readout by two silicon photomultipliers (SiPMs) directly coupled to opposite ends of the
crystal for rare-event searches. A $6 \text{ mm} \times 6 \text{ mm} \times 13 \text{ mm}$ NaI(Tl)
crystal was directly coupled to two SiPMs and characterized in a
liquid nitrogen-cooled cryostat over a temperature range of 94$-$293 K. The light yield, energy resolution, and scintillation decay time were measured using $\gamma$-ray peak from a $^{241}$Am source. After correcting for optical crosstalk contributions, the light yield increased, reaching $17.7 \pm 1.1$ photoelectrons/keV at 238 K, corresponding to a 34.5% enhancement relative to room temperature (293 K). Furthermore, dual-channel configuration effectively suppresses random thermal noise via coincidence triggers, which together with the observed increase in light yield, provides a critical pathway toward lowering the energy threshold for dark matter and coherent elastic
neutrino$-$
nucleus scattering searches.
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All authors W. K. Kim, H. Y. Lee, K. W. Kim, H. S. Lee
Strongly Correlated Electrons
The Fate of Crystalline Topological Phenomena in the Continuum
Rajas Chari and Taylor L. Hughes
The continuum limit is a widely used theoretical construct for obtaining continuum field-theories of crystalline systems. We study the formulation of a continuum limit for gapped bosonic phases and ask whether their topological properties survive passage to the continuum. Using methods in algebraic
topology and category theory, we give a rigorous formulation of the continuum limit and construct a surjective global map relating crystalline topological phases across all finite point-group
symmetries to continuum invertible topological phases. Consequently, we find that some
lattice phases admit no continuum limit, while distinct
lattice phases that do admit a continuum limit can share the same continuum image, hence implying that some
lattice topological data can collapse. Conversely, we find that every continuum invertible phase admits a faithful crystalline realization. In addition to the general framework, we apply it to several examples, including studies of a 2D rotation-symmetric phase, higher-order topological phases, and the mixed
spin-
lattice anomaly of the deconfined
quantum critical point between an antiferromagnet and valence bond solid.
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Strongly Correlated Electrons
Quetzalcoatlite as a Disorder-Free Platform for Chiral Magnetism and Frustration
Aleksandar Razpopov, P. Peter Stavropoulos, Felix Flicker et al. (+2 more)
The natural mineral quetzalcoatlite Zn$_6$Cu$_3$(TeO$_6$)$_2$(OH)$_6$ $\cdot$ (Ag$_x$Pb$_y$Cl$_{x+2y}$) is a structurally ideal kagome magnet, providing a platform for exploring the interplay of
geometric frustration, chirality, and tunability in a disorder-free framework. Here, we present the (first) comprehensive ab initio study of its electronic and
magnetic properties. The electronic structure is dominated by localized half-filled Cu $d_{x^2-y^2}$ orbitals that become insulating through electronic correlations. Mapping the low-energy physics onto a Heisenberg model reveals that the magnetism is governed primarily by two exchange interactions: a nearest-neighbor intralayer kagome coupling and a next-nearest-neighbor interlayer coupling. Their competition stabilizes an unconventional three-dimensional
chiral magnetic state. Each kagome layer hosts a $\sqrt{3}\times\sqrt{3}$ order, while adjacent layers are rotated by $60^\circ$, producing a right-handed spiral along the crystallographic $c$-axis. This intrinsic
chiral order emerges naturally from the
crystal structure and
magnetic interactions, establishing quetzalcoatlite as a distinctive realization of
chiral magnetism on a perfect kagome
lattice. At the same time, the small energy scale of the exchange interactions places the material close to competing
magnetic regimes, suggesting that moderate pressure, chemical substitution, or structural modifications may strongly enhance frustration, suppress long-range order, and potentially drive the system toward a
quantum spin-
liquid state.
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All authors Aleksandar Razpopov, P. Peter Stavropoulos, Felix Flicker, Michael R. Norman, Roser Valentí
High Energy Astrophysical Phenomena
ATLAS22kjn (AT 2022fpx): A Coronal Line Emitter with an Early Light Curve Bump and Mid-Infrared Dust Echo
Athena C. Engholm, Jason T. Hinkle, Benjamin J. Shappee et al. (+14 more)
We present an analysis of ATLAS22kjn (AT 2022fpx), whose high-ionisation coronal lines (CLs) and pre-peak light curve bump provide distinctive opportunities to investigate the physical mechanisms powering
tidal disruption events (TDEs). In addition to CLs, the optical spectra show common TDE features, including a strong, blue continuum and broad Balmer and He II lines. The CLs appear before UV/optical light curve peak, preceding the detection of X-rays by $\sim 300$ days and persisting after X-rays are no longer detected, suggesting the X-ray emission is obscured at both early and late times. Using the CL luminosities, we constrain the temperature
evolution of the ionising source, finding a decrease of $\lesssim 10 \%$ over 500 days. In the UV/optical light curve, we observe a $9 \substack{+4 \\ -2}$ day bump that peaks $125 \substack{+5 \\ -3}$ rest-frame days before the peak of the main
flare. Although we cannot definitively determine the origins of the bump, we find that its timescale and luminosity are most consistent with theoretical predictions for a precursor feature produced by a stream-stream collision or a wind-stream collision. ATLAS22kjn also shows a prominent
dust echo in its mid-infrared (MIR) light curves, indicating a high
dust covering fraction $f_c \simeq 0.40 \pm 0.03$, similar to the covering fractions of other CL-emitting TDEs. From the multi-wavelength observations of ATLAS22kjn, we estimate the size and relative radii of the emission regions in its
nuclear environment and determine that the CL region lies between the broad line region and the MIR-emitting
dust. ATLAS22kjn demonstrates the importance of multi-wavelength and early-time observations, and the utility of CLEs in characterising the otherwise unobservable EUV/ultrasoft X-ray emission of TDEs.
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All authors Athena C. Engholm, Jason T. Hinkle, Benjamin J. Shappee, Katie Auchettl, Dhvanil D. Desai, Willem B. Hoogendam, Christopher S. Kochanek, Nicholas Earl, K. Decker French, Michael A. Tucker, Chris Ashall, Aaron Do, Allison Blum, Thomas de Jaeger, Mark E. Huber, Anna Payne, Jose L. Prieto
High Energy Physics (Theory)
Macroscopic origin of the topologically twisted index on $T^2 \times \Sigma_{\mathfrak{g}}$
Nikolay Bobev, Vasil Dimitrov and Dario Martelli
We construct a novel family of non-supersymmetric, asymptotically locally AdS$_5$ solutions of five-dimensional minimal gauged supergravity. In Lorentzian signature the solutions describe finite temperature rotating electro-magnetically charged black strings with $S^1\times \Sigma_{\mathfrak{g}}$ horizon
topology. In Euclidean signature the solutions are completely smooth and are asymptotic to $T^2\times \Sigma_{\mathfrak{g}}$. We present a detailed analysis of the thermodynamic properties of these gravitational backgrounds, compute their regularized on-shell action and analyze the extremal and supersymmetric limits. The supersymmetric, but non-extremal, limit of the Euclidean backgrounds is a family of complex black saddles and it provides the
holographic dual description of the topologically twisted index of 4d $\mathcal{N}=1$ SCFTs placed on $T^2\times \Sigma_{\mathfrak{g}}$. We show that the supergravity regularized on-shell action in this limit is in agreement with the large $N$ limit of the topologically twisted index in the dual SCFT.
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High Energy Physics (Phenomenology)
Anomalies in Hadronic $B$ Decays
Marianne Bouchard and David London
The decays $B\to PP$, where the pseudoscalar $P$ is a $\pi$ or $K$, have been studied under the assumption of flavour SU(3)
symmetry [SU(3)$_F$]. The global fit shows a 3.6$\sigma$ discrepancy with the Standard Model (SM). Separate fits for $\Delta S = 0$ and $\Delta S = 1$ decays find parameter sets that differ by a factor of 10, suggesting 1000% SU(3)$_F$ breaking, significantly larger than the $\sim$ 30% breaking expected in the SM. This study has been extended to include final states with $\eta$ and $\eta'$
mesons. The resulting global fit, once again under the assumption of SU(3)$_F$
symmetry, is worse, with a 4.1$\sigma$ deviation from the SM. When theoretical constraints $|\widetilde C/\widetilde T| = 0.2$ or $\widetilde A = 0$ are imposed, the fits worsen, with the discrepancy approaching 5$\sigma$. These results hint at new-physics contributions to these decays.
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Statistical Mechanics
Geometry of Noisy Quantum Many-Body Dynamics with Continuous Symmetries: Entanglement and Correlations
Marco Lastres and Sanjay Moudgalya
We study
unitary quantum dynamics in noisy Brownian models with global continuous
symmetries, such as $U(1)$ and $SU(2)$, focusing on Rényi
entanglement entropies and hydrodynamic and non-hydrodynamic correlators. By mapping the averaged late-time dynamics to the low-energy physics of effective replica
Hamiltonians, we find that the
evolution is controlled by the
quantum geometry of their ground-state
manifolds, which is directly related to the geometry of $k$-commutants—the
symmetry algebra of $k$ replicas of the system. In interacting systems, these $k$-commutants are generically determined solely by the
symmetries of the system, independent of microscopic details of the noisy
evolution. This allows us to use the time-dependent variational principle (TDVP) to provide simple
geometric explanations for the sub-ballistic Rényi
entanglement growth and the anomalous decay of non-hydrodynamic correlators in interacting systems with continuous
symmetries. We find this behavior to be intimately connected to singularities within the $k$-commutant
manifolds, arising from frozen “void” states in the
Hilbert space that exist due to continuous on-site
symmetries. This also demystifies the important role of voids in the dynamics of these observables, previously identified in $U(1)$ symmetric systems. We compare these behaviors in interacting systems with Abelian and non-Abelian continuous
symmetries and in free-
fermion systems, which differ in the geometry of their $k$-commutants. Ultimately, this work provides a general
geometric framework for systematically studying observables in noisy systems with continuous
symmetries, including Haar-random
circuits.
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Cosmology and Nongalactic Astrophysics
A new measurement of the FRB DM-galaxy cross correlation and a first joint analysis with the kinematic SZ effect
Samuel McCarty, Liam Connor, Kritti Sharma et al. (+8 more)
Understanding the distribution of
cosmic baryons is crucial for advancing cosmology and
galaxy formation. Localized Fast
Radio Bursts (FRBs) are a promising new probe of the diffuse gas, but measurements thus far have been limited by small sample size. In this work, we measure the FRB dispersion measure (DM)-
galaxy cross correlation with 130 localized FRBs, including new spectroscopic host
redshifts from the DSA-110, and the DESI Legacy Survey Bright
Galaxy Sample. We detect this signal at the highest significance to date ($6.5\sigma$) in both configuration and harmonic space. By comparing to simulations and a
halo model, we demonstrate that this statistic can constrain the strength of baryonic feedback. Our measurements disfavor a no-feedback scenario in which gas traces the underlying dark matter at $\sim\,9\sigma$. In addition to small scale feedback, this represents one of the first direct measurements of the clustering of electrons on scales larger than a few Mpc. We compare our measurement to recent kinematic Sunyaev-Zeldovich effect (kSZ) studies, which show good agreement despite the differences in observational methods and sample selection. Finally, we make a first attempt at breaking the kSZ optical depth degeneracy with FRBs, jointly measuring the growth rate of large-scale structure $f\sigma_8$. With future samples, FRB two-point statistics will provide precision constraints on the distribution of
cosmic baryons and complement other probes.
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All authors Samuel McCarty, Liam Connor, Kritti Sharma, Simone Ferraro, Vikram Ravi, Elisabeth Krause, Boryana Hadzhiyska, Vishnu Balakrishnan, Casey Law, Pranav Sanghavi, Kaitlyn Shin