Statistical Mechanics
Renormalization-Group Fixed Points Not Associated with Universality Classes
Ko Okumura
Universality classes have recently been identified for self-similar solutions of nonlinear partial differential equations (PDEs) as consequences of repeated renormalization-group (RG) transformations that eliminate irrelevant structures. Whether all RG fixed points are associated with universality classes, however, remains unclear. We address this question by extending a recently proposed predictive RG framework to traveling-wave solutions, using the Burgers and Korteweg–de Vries (KdV) equations as examples. Traveling waves can be mapped onto self-similar forms via a logarithmic transformation. Applying the predictive RG to the log-transformed governing equations yields an RG-flow analysis that reproduces shock and
soliton solutions, thereby identifying traveling waves as RG fixed points and the logarithmic variable as RG-flow time. Although the predictive RG framework has shown that self-similar fixed points are associated with universality classes, we find that the present traveling-wave fixed points do not produce the irrelevant structures whose elimination normally gives rise to universality classes. This failure originates from the logarithmic representation, which renders analytic local functions of the field and its derivatives scale invariant, thereby preventing the emergence of irrelevant structures. Traveling waves thus provide explicit examples of RG fixed points without universality classes. These observations suggest that the absence of universality classes may be generic for traveling-wave RG fixed points formulated through logarithmic coordinates. The absence of universality classes suggests that information associated with initial conditions may persist asymptotically, promoting
memory retention. The Burgers and KdV examples suggest that
memory of initial conditions can survive RG transformations, although its form remains system dependent.
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Statistical Mechanics · Cross-listed from quant-ph
The Pauli Probability Spectrum Carries the Pure-State Quantum Fisher Metric
E. A. Ramirez Trino and M. A. Rajabpour
How a
quantum state responds to small parameter changes underlies state distinguishability, many-body response, and metrological sensitivity. The Pauli probability spectrum provides a natural description of many-body
quantum states, but it is not evident how much of this response survives in the corresponding classical distribution. Here we show that, for pure states, the complete labeled Pauli distribution retains the full local metric of the pure-state
manifold, reproducing the
quantum Fisher metric up to a fixed normalization. This correspondence has a direct measurement realization: preparing a state together with its complex conjugate and performing pairwise Bell measurements between corresponding degrees of freedom converts the
quantum response into an ordinary classical distribution without losing any of the sensitivity available in the two inputs. The readout is fixed, factorizes into local pairwise measurements even for strongly entangled many-body states, and preserves the response along all parameter directions simultaneously. We trace this correspondence to the reality of the underlying operator amplitudes and show that the same mechanism extends beyond
qubits. When the correspondence fails, we identify explicitly where the missing information resides: part of the response can remain hidden in phases for identical-copy and complex-coordinate readouts, while mixed states develop transverse operator-space motion that is invisible to the Bell probabilities. These results provide a direct link between Pauli/Bell statistics, many-body response, nonstabilizerness, and
quantum geometry.
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Soft Condensed Matter · Cross-listed from physics.flu-dyn
Liquid bridges between horizontal cylinders: effects of gravity and electric fields
Agnes J. Bokányi-Tóth, Andrew J. Archer, Radu Cimpeanu et al. (+3 more)
Liquid bridges suspended between two parallel horizontal cylinders are studied using experiments, reduced-order mathematical modelling and numerical simulations. Both non-electrified and electrified configurations are considered, with the cylinders acting as electrodes between which a potential difference can be applied. The initial focus is on
equilibrium bridge shapes, while the dynamics is examined only in the non-electrified case. In the experiments,
transformer-oil bridges are investigated and modelled as perfect dielectrics. The electric field counteracts the gravitational effects and causes the bridges to rise and become flatter, with shapes that are well described by Young–Laplace-type equations containing non-local electric-field contributions evaluated using a boundary-element method. Bifurcation diagrams of these solutions are constructed by pseudo-arclength continuation to characterise the dependence of bridge shapes on
liquid volume and electric-field strength. In the absence of an electric field, the transient relaxation to
equilibrium is analysed using a reduced-order model developed using Onsager's variational principle, with comparison to direct numerical simulations. The steady states predicted by the reduced-order model agree closely with those of the full formulation over a wide parameter range, and the dynamics is well captured in the overdamped regime.
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All authors Agnes J. Bokányi-Tóth, Andrew J. Archer, Radu Cimpeanu, H. C. Hemaka Bandulasena, Gyula I. Tóth, Dmitri Tseluiko
Statistical Mechanics
Embedding Paired Free-Fermion Gaussian States into Gutzwiller-Projected Bardeen–Cooper–Schrieffer Wave Functions
Ryui Kaneko
Gutzwiller-projected Bardeen–Cooper–Schrieffer (BCS) wave functions of Abrikosov
fermions are widely used to describe
quantum many-body states. Taking the one-dimensional transverse-field Ising model as an example, we exactly embed any even-parity spinless fermionic Gaussian state representable as a paired exponential in the chosen particle basis into a projected BCS state of spinful Abrikosov
fermions. The construction provides controlled initial states for variational Monte Carlo studies of nonintegrable models.
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Materials Science
Discovery of novel magnetic Y-Mn-B compounds via advanced machine learning guided framework
Weiyi Xia, Wei Shen Tee, Maxim Moraru et al. (+2 more)
Rare-earth transition-metal borides offer critical structural motifs for permanent-magnet design; however, the manganese-rich regions within these compositional phase spaces remain largely unexplored. In this work, we develop an advanced machine-learning-assisted discovery framework to explore Y-Mn-B ternary system. Starting from over one million hypothetical structures generated from known structures in databases, we filtered promising candidates by first applying graph neural networks to predict material stability, then using machine-learning-interatomic-potential to relax their structures, and finally validating the results with first-principles calculations. We identify 5 stable and near-stable Y-Mn-B phases along with 61 metastable compounds with the formation energy within 100 meV/atom with respect to the ternary convex hull. Among them, Y2Mn7B7 and YMn4B4 are structurally analogous to the previously synthesized $R_{1+\epsilon}Fe_4B_4$ 1D incommensurate composite chain compounds. In striking contrast to the strongly suppressed Fe moments reported, our first-principles calculations reveal that the predicted Mn-chain phases preserve sizable local Mn moments (approximately 1.1 $\mu_B$) and favored
ferromagnetic ordering. Electronic structure analyses elucidate the microscopic origin of moment recovery via an enhanced exchange splitting driven by a Stoner-like instability. We also perform systematic Mn-Fe substitution to confirm the thermodynamic continuity and a monotonic enhancement of the macroscopic magnetization, from Fe to Mn. These findings indicate that targeted transition-metal substitution within a one-dimensional boride family can recover transition-metal magnetism, offering a physically interpretable route for designing new
magnetic rare-earth transition-metal borides.
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All authors Weiyi Xia, Wei Shen Tee, Maxim Moraru, Ying Wai Li, Cai-Zhuang Wang
Soft Condensed Matter · Cross-listed from physics.flu-dyn
Autonomous route to the strange attractor: the many life stages of the chaotic bubblewheel
Michael Zhao and Saverio E. Spagnolie
A body floating atop a supersaturated fluid may accumulate bubbles along its underbelly, which can render the body rotationally unstable. But rotation can strip the surface of these bubbles when they make contact with the air above. To explore this coupling we perform experiments using cylinders floating on carbonated water. The cylinders exhibit an array of distinct dynamics, including constant rolling, periodic and aperiodic oscillation, chaos, and intermittent capsizing, which can be tuned by body size, mass distribution, and gas concentration. A continuum model for the bubble density dynamics, and Galerkin projection, tie the experiment to the generalized Lorenz system and its famed chaotic attractor. Even an extremely small center-of-mass offset can have a qualitative impact on the dynamics, and an offset of as little as a few percent can fully stabilize the system. The experiment represents a highly accessible physical realization of the Lorenz system, which, owing to continuous gas loss from the fluid to the air above, sweeps slowly without intervention across a classical bifurcation diagram in time.
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Statistical Mechanics · Cross-listed from math.AP
Fixed-particle-number optimizers for the Lieb–Oxford inequality
Matthew Rosenzweig
Let $\mathsf{d}\geq1$, $0<\mathsf{s}<\mathsf{d}$, and $N\geq1$. We prove that the optimal fixed-particle-number constant $\Lambda_N(\mathsf{s},\mathsf{d})$ in the Riesz Lieb–Oxford inequality is attained and that these constants are strictly increasing in $N$. The proof combines grand-canonical concentration–compactness with a strict one-particle extension. After recentering, a limiting plan arising from a maximizing sequence may assign positive probability to several particle numbers and hence be grand-canonical. A strict $N$-particle completion excludes this case, while the inequalities $\Lambda_N>\Lambda_k$ for $k<N$ exclude limits with a fixed lower particle number. Once attainment at particle number $N$ is known, the compact-support
theorem of Di Marino and Lelotte arXiv:2607.11440, valid for all $0<\mathsf{s}<\mathsf{d}$, permits a non-product one-particle extension and yields $\Lambda_{N+1}(\mathsf{s},\mathsf{d})>\Lambda_N(\mathsf{s},\mathsf{d})$. Together, these implications close an induction beginning at $N=1$.
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Materials Science
Temperature-Induced Reorganization of Supported Zn$_3$ Clusters on Cu(111): From Minimum-Energy Structures to Finite-Temperature Ensembles
Jiayan Xu, Zheng Yu, Abhirup Patra et al. (+4 more)
Understanding the nature of catalytic active sites under reaction conditions remains a central challenge in heterogeneous catalysis. In industrial copper/zinc
oxide/alumina catalysts for methanol synthesis, small Zn-based species at the Cu interface have long been proposed as active-site candidates, yet their atomic-scale structure and stability remain controversial. Computational studies typically identify such species from optimized 0 K structures, assuming that minimum-energy configurations remain representative under reaction conditions. Here, we combine machine-learning-interatomic-potential-accelerated global optimization, molecular dynamics, and enhanced-sampling free-energy calculations to investigate supported Zn$_3$(OH)$_3$ and Zn$_3$(OH)$_2$CHOO clusters on Cu(111)-based surfaces from 0 to 450 K. While compact triangular configurations are generally favored among minimum-energy structures at 0 K, finite-temperature free-energy calculations reveal a pronounced shift toward extended linear configurations with increasing temperature. This transition is driven primarily by entropic stabilization and cannot be inferred from potential energies alone. Molecular dynamics further shows substantial cluster mobility on pristine Cu(111), indicating that long-term persistence depends not only on configurational stability but also on surface mobility. Surface Zn alloying strongly suppresses
diffusion, thereby stabilizing isolated interfacial Zn species. Together, these results show that thermodynamically relevant structures of supported Zn-based clusters can differ fundamentally from static 0 K predictions because of competing enthalpic and entropic effects. Our findings highlight the limitations of identifying catalytic active sites solely from 0 K structures and underscore the importance of explicit finite-temperature sampling in catalyst modeling.
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All authors Jiayan Xu, Zheng Yu, Abhirup Patra, Amar Deep Pathak, Sharan Shetty, Detlef Hohl, Roberto Car
Statistical Mechanics · Cross-listed from cs.LG
Iterative tensor network transformations for element-wise evaluation of elementary and filtering functions
Xiao Wang, Tomohiro Hashizume, Pia Siegl et al. (+1 more)
Tensor networks are powerful formats for compressing large-scale data. However, their application to general data processing has been limited by the difficulty of performing nonlinear operations. Here, we introduce iterative tensor network transformations (ITNTs), a general algorithmic framework for the element-wise evaluation of elementary and nonlinear filtering functions on data encoded as tensor trains (TTs), a class of tensor networks. Our approach operates entirely in the compressed domain, enabling efficient computation on exponentially large
datasets while maintaining a controlled computational cost. We demonstrate its power in two key areas: (I) evaluating highly nonlinear elementary and filtering functions on a 3D reactive flow field, enabling high-fidelity reaction rate computation and region filtering, and (II) finding extrema in complex optimization problems, such as solving Max-SAT instances on spaces up to $2^{70}$ configurations. These results establish ITNT as a foundational tool that provides tensor network methods with the capability for general-purpose data science and large-scale optimization.
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All authors Xiao Wang, Tomohiro Hashizume, Pia Siegl, Dieter Jaksch
Superconductivity
Demonstration of a scalable all-solid-state refrigerator exploiting diffusion geometries and limiting interfacial conductances at temperatures below 1 kelvin
Robert M. Young, Zachary Stegen, John X. Przybysz et al. (+32 more)
Solid-state refrigerators using Normal-metal/
Insulator/
Superconductor (NIS) junctions have previously demonstrated excellent electron cooling but limited ability to cool
phonons. The energy gap of the
superconductor is used as an energy filter to allow higher than average energy electrons to preferentially tunnel from the normal-metal through the
insulator into the
superconductor where they travel as quasi-particles. Typically, the heat is moved and work is done to deposit hot quasi-particles into a normal-metal quasi-particle trap for rejection to the next refrigeration stage. Realizing that (1) the quasi-particles flow diffusively, driven by a concentration gradient in the electric field-free
superconductor, and (2) that the undesirable backwards leaking of heat from the hot-side trap can be reduced by engineering the geometry and materials at the
superconductor-to-trap interface, enhanced cooling can be achieved. Fabrication of the refrigerator was accomplished using a tungsten and titanium-tungsten
alloy as the cold-side normal-metal, aluminum
oxide as the
insulator, aluminum as the
superconductor, and gold as the trap, with the cold-side NIS portion being attached to the hot-side gold trap by bump bonding. The refrigerator consisted of 1121 junction pairs, each pair being an SINIS unit, all electrically connected in series. Using this we have measured the effective
phonon temperature of a 3.9 mm x 3.9 mm x 0.65 mm silicon chip driven down to 70 mK from a bath temperature of 120 mK, and down to 174 mK from a 271 mK rejection temperature (a cooling of -97 mK). This is the first demonstration of the sub 1 K cooling of an entire silicon chip using NIS junctions.
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All authors Robert M. Young, Zachary Stegen, John X. Przybysz, Edward R. Engbrecht, Aaron A. Hathaway, Justin C. Hackley, Kirby B. Myers, Christian C. Thorpe, Aurelius L. Graninger, Robert Miller, Diego A. Morales, Roberto D. Carcamo, Glen Walters, Jeric P. Sarad, Nicholas F. Pleim, Seth Whitsitt, Joshua T. Shipman, Anil Erol, Melissa G. Loving, Evan Donohue, Corey A. Kegerreis, Benjamin Dalfort, Moe S. Khalil, Christopher Pinion, Randi Jaramillo, John Milinichik, Sandro J. Di Giacomo, Thomas Zodda, Nilesh Tralshawala, Gregory R. Boyd, Jonathan M. Cochran, Katherine A. Maddock, Michael P. De Feo, Aaron A.Pesetski, Marc E. Sherwin
Materials Science
Over what length scale does an inorganic substrate perturb the structure of a glassy organic semiconductor?
Kushal Bagchi, Chuting Deng, Camille Bishop et al. (+6 more)
While the bulk structure of vapor-deposited glasses has been extensively studied, structure at buried interfaces has received little
attention, despite being important for organic electronic applications. To learn about glass structure at buried interfaces, we study the structure of vapor-deposited glasses of the organic
semiconductor DSA-Ph (1,4-di-[4-(N,N-diphenyl)amino]styryl-benzene) as a function of film thickness; structure is probed with grazing incidence X-ray scattering. We deposit on silicon and gold substrates and span a film thickness range of 10-600 nm. Our experiments demonstrate that interfacial molecular packing in vapor-deposited glasses of DSA-Ph is more disordered compared to the bulk. At a deposition temperature near room temperature, we estimate ~ 8 nm near the substrate can have modified molecular packing. Molecular dynamics simulations of a coarse-grained representation of DSA-Ph reveal a similar length scale. In both the simulations and the experiments, deposition temperature controls glass structure beyond this interfacial layer of a few nanometers.
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All authors Kushal Bagchi, Chuting Deng, Camille Bishop, Yuhui Li, Nicholas E Jackson, Lian Yu, M.F. Toney, J.J. de Pablo, M.D. Ediger
Soft Condensed Matter
Rejuvenation versus overaging: The effect of cyclic loading/unloading on the segmental dynamics of PMMA glasses
Trevor Bennin, Enran Xing, Josh Ricci et al. (+1 more)
The acceleration of structural relaxation or physical aging by deformation, known as overaging, has been reported in experiments and simulations of
polymer and colloid glasses, and correctly accounting for overaging is important for the prediction of the long-term behavior of
polymer glasses in engineering applications. Here the effects of cyclic loading/unloading on the segmental dynamics and mechanical properties of PMMA glasses are investigated using a probe reorientation technique and time-aging time superposition of the mechanical response, respectively. Sets of 5000 tensile loading/unloading cycles were performed at temperatures between Tg - 10 K and Tg - 25 K with cycle extension strains ranging from 0.003 to 0.007. After cycling, the segmental dynamics measured with the probe reorientation technique either remained unchanged or were faster relative to an undeformed sample. The relaxation times of cycled glasses recovered with a common time scale on the order of their aging time, indicating that they retain a
memory of their original age, as opposed to a full erasure of their thermal and mechanical history. Surprisingly, changes as a result of cycling were more obvious in probe reorientation measurements than in the mechanical properties, suggesting that the probe reorientation technique can sensitively detect nonlinear effects of deformation. No evidence of overaging was observed in the optical or mechanical measurements as a result of these cyclic loading/unloading experiments.
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All authors Trevor Bennin, Enran Xing, Josh Ricci, M.D. Ediger
Soft Condensed Matter
Controlling Structure and Properties of Vapor-Deposited Glasses of Organic Semiconductors: Recent Advances and Challenges
Kushal Bagchi and MD Ediger
The last decade has seen great progress in manipulating the structure of vapor-deposited glasses of organic
semiconductors. By varying the substrate temperature during deposition, glasses with a wide range of density and molecular orientation can be prepared from a given molecule. We review recent studies that show the structure of vapor-deposited glasses can be tuned to significantly improve the external
quantum efficiency and lifetime of OLEDs (organic light emitting diodes). We highlight the ability of molecular simulations to reproduce experimentally observed structures, setting the stage for in-silico design of vapor-deposited glasses in the coming decade. Finally, we identify research opportunities for improving the properties of organic
semiconductors by controlling the structure of vapor-deposited glasses.
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Quantum Gases
Hidden Ergodic Relaxation in the Quench Dynamics of a Bichromatic Mott Lattice
Áttis V. M. Marino, Rhombik Roy, M. A. Caracanhas et al. (+5 more)
We investigate the nonequilibrium dynamics of strongly interacting
bosons in a finite bichromatic Mott
lattice following a sudden quench of the secondary
lattice amplitude. The coefficient
entropies and second Rényi
entropy exhibit pronounced growth toward their Gaussian Orthogonal Ensemble (GOE) predictions from random-
matrix theory, consistent with GOE-like statistical spreading in the employed multiconfigurational representation. In striking contrast, experimentally accessible observables, including the momentum distribution, fragmentation, and Glauber correlation functions, remain nearly unchanged throughout the
evolution. For the sampled strong quenches, the coefficient
entropies, second Rényi
entropy, and the $N$-body coefficient spreading collapse onto a common relaxation trajectory that becomes largely independent of the perturbation strength. Our results reveal an emergent hidden ergodic relaxation beneath the persistent local Mott-like order. An effective embedded random-
matrix model captures the qualitative crossover from restricted to extensive
Hilbert-space spreading, providing an interpretive framework for the observed relaxation dynamics.
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All authors Áttis V. M. Marino, Rhombik Roy, M. A. Caracanhas, N. D. Chavda, Antônio M. S. Macêdo, V. S. Bagnato, Robin P Sagar, B. Chakrabarti
Mesoscale and Nanoscale Physics
Emissivity by Design: Geometric Mesh Inductance Governs Thermal Radiation in Metallic Nanowire Networks
Amaury Baret and Ngoc Duy Nguyen
The thermal infrared emissivity of metallic nanowire networks - the property that makes them candidate low-emissivity transparent electrodes - follows regularities that have resisted physical explanation: a strong wire-diameter dependence with no wire-length dependence, a correlation with sheet resistance that breaks down above ~15 ohm/sq, and an angular signature that turns from dielectric-like to metallic as the network densifies. We show that all of them follow from one local
geometric length, the average inter-wire gap g, acting through the
geometric inductance of a mesh finer than the thermal wavelength: $X_L = Z_0 (g/\lambda) \ln(2g/\pi D)$, a parameter-free reactance that exceeds the ohmic loss and, unlike the DC sheet resistance, stays finite instead of diverging at the percolation threshold. Since the gap is fixed by areal density and wire diameter alone, the optics is length-independent and decoupled from percolative transport; what has been read as a second, optical percolation is instead a smooth impedance crossing. With a single fitted parameter the theory reproduces 56 silver-nanowire samples across four diameters to a mean absolute error of 0.04, collapses them onto one universal curve, and - unchanged - predicts the emissivity-transmittance data of five independent groups and the measured spectral emissivity, including the silica
phonon band. Because this reactance contains no material constant, the inter-wire gap emerges as the master design variable for the radiative properties of metallic nanowire transparent conductors.
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Mesoscale and Nanoscale Physics
Local magnetic resonance of scalar spin chirality
Mar Ferri-Cortés and Joaquin Fernández-Rossier
Quantum states with finite scalar
spin chirality carry an orbital
magnetic moment that has eluded direct measurement. We show that a local drive breaks the cyclic
symmetry and activates chirality-changing transitions. We propose two complementary probes: direct chirality resonance and chirality-resolved
spin resonance. Lindblad simulations demonstrate their feasibility in locally addressable
spin platforms, including scanning tunneling microscopy, silicon donors, and
quantum dots.
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Statistical Mechanics · Cross-listed from astro-ph.SR
Tracking nonlinear solar-wind dynamics over three solar cycles using Wind observations
Dario Javier Zamora and Facundo Maximo Abaca
The
solar wind is a turbulent, weakly collisional
plasma characterized by non-Gaussian fluctuations, long-range correlations, and multifractal dynamics. We investigate the long-term
evolution of these properties using hourly
proton density measurements obtained directly by the Wind spacecraft over 1995–2025. The use of a single-spacecraft
dataset provides an independent test of previous results derived from the multi-spacecraft OMNI database. The three components of the nonextensive $q$-triplet are estimated within one-year sliding windows shifted monthly: $q_{stat}$ from the distribution of density increments, $q_{rel}$ from the decay of the autocorrelation function, and $q_{sens}$ from the multifractal spectrum. Their mean values, $q_{stat}=1.71\pm0.07$, $q_{rel}=4.62\pm0.52$, and $q_{sens}=-0.45\pm0.27$, confirm the persistent presence of heavy-tailed statistics, slow relaxation, and weakly chaotic multifractal dynamics. The parameters nevertheless exhibit distinct temporal variability and relationships with
solar activity. The
Fourier spectrum of $q_{stat}$ contains a dominant period of approximately $10.1$ years, while its correlation with the sunspot number is positive and moderate ($r=0.611$). Correlation and mutual-information analyses show that $q_{stat}$ is primarily associated with
solar proxies, whereas $q_{sens}$ displays stronger relationships with geomagnetic indices and $q_{rel}$ exhibits weaker dependencies. An anomalous enhancement of $q_{stat}$ around 2004 coincides with a sequence of intense interplanetary disturbances, although possible effects related to Wind's orbital transition must also be considered. These findings demonstrate the robustness of the nonextensive description and show that the statistical and dynamical properties of
solar wind
proton density show evidence of modulation by
solar activity.
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Mesoscale and Nanoscale Physics · Cross-listed from quant-ph
Multi-purpose quantum laboratories from superconducting circuits
Arpit Arora, Emily M. Been, William Munizzi et al. (+4 more)
Superconducting
circuits (SCs) are the cornerstone of modern
quantum technology, enabling scalable computing through coherent control of macroscopic
quantum states. Through a legacy that predates modern
quantum computing, SCs have emerged as high-precision instruments for discovery. In this review, we highlight the role of SCs as general-purpose
quantum laboratories, outlining the emerging landscape of correlated matter-
circuit science. We review and unify the capabilities of superconducting
quantum hardware across condensed matter, high energy and
quantum information sciences. We trace the technical
evolution of these architectures, illustrating how their foundational development has culminated in a toolkit for resolving the complexities of macroscopic
quantum states.
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All authors Arpit Arora, Emily M. Been, William Munizzi, Joel Wang, Taylor L. Patti, Aaron Chou, Prineha Narang
Quantum Gases · Cross-listed from hep-th
Yu-Ping An, Peng-Bo Ding, Zhen-Han Jin et al. (+1 more)
A long-standing obstacle in
quantum turbulence has been the difficulty of sustaining robust statistical steady states, preventing unambiguous identification of universal
vortex organization and kinetic scaling. We construct such a steady state in two-dimensional
holographic superfluid
turbulence by continuous Landau-instability driving, sustaining ${\sim}2500$
vortices free from transient artifacts. The topological charge structure factor $S_c(k)$ reveals Class I disordered hyperuniformity with $S_c(k)\propto k^{\alpha>1}$ as $k\to0$, where $k$ is the wavenumber. This constitutes the strongest long-range order of its kind and its first observation in a strongly driven, far-from-
equilibrium quantum fluid with topological defects as the organizing principle, establishing a novel non-
equilibrium vortex phase. Exploiting this platform, we resolve the scaling controversy: the apparent $k^{-5/3}$ signature in the kinetic energy spectrum is a narrow crossover between the $k^{-1}$ single-
vortex and $k^{-3}$ core regimes, not a genuine Kolmogorov inertial range. The real-space second-order structure function provides decisive evidence via $S_2(r)\propto \ln r$ where $r$ is the spatial separation, with no $r^{2/3}$ Kolmogorov scaling, ruling out a true inertial cascade. These findings reveal that strongly coupled
quantum turbulence lacks an inverse cascade due to the absence of macroscopic Onsager clusters, demonstrating energy transport fundamentally distinct from weakly coupled superfluids.
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All authors Yu-Ping An, Peng-Bo Ding, Zhen-Han Jin, Li Li
Materials Science
PowderLine: a programmatic powder diffraction analysis application
Adam A. Corrao, Jennifer A. Perez, John D. Langhout et al. (+3 more)
Whole-pattern fitting methods, such as Rietveld refinement, excel at extracting detailed structural, chemical, and microstructural information from powder diffraction data. Obtaining reliable results requires both considerable expertise and software-specific knowledge, and applying these methods at scale typically relies on custom scripts written for each application. High-throughput experiments and autonomous self-driving laboratories increasingly utilize powder diffraction analysis to proceed programmatically and to return structured, machine-readable results. Here, we introduce PowderLine, a Python application that encapsulates a complete refinement into a single declarative recipe, validates that recipe against a versioned schema, and executes it through refinement software to return structured results. The refinement recipe is an all-inclusive, machine-readable and -writable description of either Rietveld or single peak analysis that users, scripts, and automated
agents can specify and run in the same way. As a result of PowderLine's composability, it naturally fits into interactive, scripted, and autonomous workflows alike.
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All authors Adam A. Corrao, Jennifer A. Perez, John D. Langhout, Megan M. Butala, Thomas A. Caswell, Daniel Olds