Materials Science · Cross-listed from physics.comp-ph
A unified variational framework for phase-field fracture and third-medium contact in finite deformation hyperelasticity
Jaemin Kim, Gukheon Kim, Sungmin Yoon et al. (+1 more)
This paper presents a unified variational framework that integrates phase-field fracture (PFF) and third-medium contact (TMC) within finite deformation hyperelasticity. The key idea is that both crack and contact are treated through regularization: the sharp crack
topology is regularized into a diffuse damage field, while the discrete contact interface is regularized by a compliant fictitious medium with auxiliary fields. This strategy eliminates the need for explicit contact detection or crack tracking
algorithms. The framework is validated through two-dimensional three-point bending and three-dimensional Brazilian disk test simulations, demonstrating the interplay between contact-induced stress concentration and crack nucleation/propagation. In particular, the Brazilian disk simulation naturally reproduces secondary crushing-type fracture zones near the contact regions – a phenomenon consistently observed in experiments yet inaccessible to simplified loading models. These results pave the way for predictive simulation of coupled contact-fracture phenomena without recourse to explicit interface tracking.
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All authors Jaemin Kim, Gukheon Kim, Sungmin Yoon, Dong-Hwa Lee
Materials Science · Cross-listed from physics.bio-ph
Advancing Food Nanotoxicology with Microphysiological Systems: Rebalancing the Risk/Benefit Ratio Toward Safer Nano-Enabled Food Innovations
Georges Dubourg
Incorporating nanomaterials into food products provides key benefits, including extended shelf life, improved safety, and enhanced quality and texture. These innovations could help tackle major challenges in modern food systems, such as reducing waste and enhancing food quality and safety. However, potential toxicity remains a concern, compounded by the lack of physiologically relevant models for assessing ingested nanomaterials. Traditional in vitro and in vivo approaches often fail to mimic gastrointestinal complexity, resulting in inconsistent and non predictive nanotoxicity data that hinder accurate risk assessment of nano enabled foods. To address this gap, this review evaluates the potential of microphysiological systems (MPS), particularly gut-targeted MPS, for modeling gastrointestinal nanoparticle exposure. It examines how MPS technologies replicate key physiological processes relevant to food specific risk assessment, including intestinal barrier function, microbiota immune interactions, and gut organ communication. A comparative analysis of technological advances and their applications in nanotoxicology explores how MPS can be better adapted for nanofood safety evaluation.
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Materials Science
Thermal conductivity of CdCr$_{2}$Se$_{4}$ ferromagnet at low temperatures: role of grain boundaries and porosity
Jiří Hejtmánek, Kyo-Hoon Ahn, Zdeněk Jirák et al. (+5 more)
It is unambiguously demonstrated that the low temperature
magnon specific heat in a ferromagnet varies as T$^{3/2}$ and the
magnon thermal conductivity, due to T$^{1/2}$ - dependent effective velocity of
magnons, as T$^{2}$. The confirmation of these model comportments is based on the experimental study of chalcospinel CdCr$_{2}$Se$_{4}$, which represents relatively rare example of a
ferromagnetic insulator (T$_{C}$ = 130 K) without undesirable masking contributions of the itinerant electron excitations and
nuclear specific heat that both make impossible to conclusively unveil the role of
magnons. The ratio of the
magnon to
lattice specific heat is found to reach 87:13 at 2 K and is in accordance with predictions based on the
spin-wave stiffness D = 33.5 meVA$^{2}$ and Debye temperature ${\theta}_{D}$ = 237 K. On the other hand, the ratio of the
magnon to
phonon thermal conductivity reaching 27:73 at 2 K is much lower than expected for standard model of the grain boundary limited transport. This suggests that mean free paths for long-wavelength
magnon/
phonon heat carriers are largely different - shorter than the grain size (of 1${\mu}$m) for
magnons and longer than grain size for
phonons. The
phonon dominated low temperature thermal conductivity exhibits, moreover, a T$^{2.3}$ temperature dependence instead of the standard predicted model in T$^{3}$. The relevant scattering mechanisms, both the
phonon frequency independent and dependent ones, are discussed in detail.
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All authors Jiří Hejtmánek, Kyo-Hoon Ahn, Zdeněk Jirák, Petr Levinský, Jiří Navrátil, Sandy Al Bacha, Emmanuel Guilmeau, Karel Knížek
Statistical Mechanics
Coarse-grained Shannon entropy of random walks with shrinking steps
Alexander Feigel and Alexandre V. Morozov
In one-dimensional diffusive processes with discrete steps characterized by geometrically decaying magnitudes, the usual Gaussian broadening familiar from Brownian motion is replaced by bounded probability distributions over particle positions that are characterized by multi-scale fractal structures. In this work, we study random walks with shrinking steps (known as Bernoulli convolutions), focusing on their behavior in the vicinity of the dyadic contraction ratio 1/2. Our analytical and numerical results show that the coarse-grained Shannon
entropy of particle distributions induced by Bernoulli convolutions exhibits a local maximum at the dyadic ratio, arising from the competition between diffusive spreading, which increases
entropy, and emergent fine structure, which tends to decrease it. This
entropy maximum is a general property of systems driven by non-Gaussian discrete noise, whose dynamics near stable fixed points can be viewed as an autoregressive process - an approximation that is mathematically equivalent to unbiased random walks with shrinking steps. We discuss potential implications of Bernoulli convolution dynamics for protocell self-replication and vesicle proliferation, establishing a link between our information-theoretic approach and biophysical models of
cell division.
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Mesoscale and Nanoscale Physics
Topology as a Design Variable for Multiproperty Engineering in Synthesized 4-5-6-8 Carbon Nanoribbons
Djardiel da S. Gomes, Isaac M. Felix, Lucas L. Lage et al. (+3 more)
Nonbenzenoid carbon frameworks expand low-dimensional material design via controlled asymmetry. Here, we show the experimentally realized 4-5-6-8 carbon nanoribbon establishes a
topology-driven paradigm for multiproperty engineering, not just a
graphene variant. Using hybrid DFT, tight-binding, and molecular dynamics in a multiscale framework, we demonstrate the
symmetry-broken
lattice stabilizes hierarchical bonds within standard energy ranges. This geometry produces a robust semiconducting state (hybrid gap >1 eV) and enables strain as a controllable modulation parameter. A tight-binding
Hamiltonian fitted only at
equilibrium accurately captures strain-dependent band
evolution, proving the essential physics is
topology-dominated. Mechanical analysis reveals high stiffness with fracture governed by the largest polygons, showing asymmetry redistributes stress without compromising integrity. Intrinsic
phonon scattering suppresses thermal conductance, enabling favorable thermoelectric performance without extrinsic disorder. Optical response confirms non-equivalent ring connectivity reorganizes interband transitions, promoting strong visible absorption and efficient photocarrier generation. These results position
topology as a governing parameter coupling elasticity, electronics, thermal transport, and optics, establishing the 4-5-6-8 nanoribbon as a unified platform for predictive design of multifunctional carbon materials.
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All authors Djardiel da S. Gomes, Isaac M. Felix, Lucas L. Lage, Douglas S. Galvão, Andrea Latgé, Marcelo L. Pereira Junior
Materials Science
Interfacial properties of MoS2 thin films grown on functional substrates
Hafiz Sami Ur Rehman, Nunzia Coppola, Alice Galdi et al. (+8 more)
Interface chemistry and defect formation in MoS2 thin films grown on single
crystal substrates critically determine the electronic structure of MoS2 and thus can strongly modify material functionality relevant for many applications, including electronics, optoelectronics, and energy related catalysis. We investigate MoS2 grown on three technologically relevant substrates, namely SrTiO3(111), c-axis Al2O3(0001) and 6H-SiC(0001). Experimental investigations by temperature dependent resistivity, photoemission spectroscopy and scanning transmission electron microscopy with coupled energy dispersive spectroscopy, with the support of theoretical calculation by Density Functional Theory, allow the identification of the substrate induced specific defects and their correlation with the electronic properties. Ti interdiffusion in SrTiO3/MoS2 generates donor like states near the
Fermi level, leading to metallic transport. Al2O3/MoS2 exhibits a high density of sulfur related defects that introduce localized states and yield nearly temperature independent conductivity. SiC/MoS2 exhibits significant interface disorder resulting in a semiconducting temperature dependent resistivity, yet deviating from the ideal bulk like behavior. These results demonstrate how substrate choice governs defect formation and ultimately dominates the electronic behavior of MoS2 thin films, making the control of film substrate interactions essential for the engineering of new functional devices.
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All authors Hafiz Sami Ur Rehman, Nunzia Coppola, Alice Galdi, Sandeep Kumar Chaluvadi, Shyni Punathum Chalil, Pasquale Orgiani, Sara Passuti, Regina Ciancio, Paolo Barone, Luigi Maritato, Carmela Aruta
Statistical Mechanics
Data-driven, non-Markovian modelling of weather in the presence of non-stationary, non-Gaussian, and heteroskedastic climate dynamics
Thomas Sayer and Andrés Montoya-Castillo
While the generalized Langevin equation (GLE) is a powerful tool to understand the behavior of complex dissipative systems, driving by external fields renders standard GLE construction workflows invalid. Filtering approaches that separate fluctuations from the non-
equilibrium response can sometimes circumvent the need for a non-
equilibrium formalism when the residual fluctuations are homoskedastic, stationary, and preferably Gaussian. Here, we introduce the temperature time series from Boulder, Colorado, as representative of the more general and complex case where the filtered time series remains non-Gaussian, non-stationary, and heteroskedastic. With this example, we develop a protocol to build an accurate and efficient low-dimensional description of the weather fluctuations. Our protocol classifies the weather data based on the position in the annual cycle, and introduces local homoskedasticity as a metric to identify seasons of likely stationarity. Within these seasons, we build pseudo-
equilibrium models. Leveraging state-based generalized master equation modelling as an alternative to the GLE, we resolve difficulties like non-Gaussianity and position dependence of the
memory (friction) kernel. Our data-driven approach accurately reproduces the evolving fluctuations of the Boulder temperature time series, illustrating the feasibility of our method as a general tool to describe driven, dissipative systems.
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Strongly Correlated Electrons
Proliferation transitions from a topological phase in $2+1$ dimensions
Meng Cheng and Nathan Seiberg
We consider phase transitions out of a general topological phase in $2+1$ dimensions. We assume that the transition is triggered by a single Abelian anyon, which becomes light near the transition and whose worldlines proliferate after the transition. (This proliferation is often referred to as “condensation.”) We describe the transition using a continuum field theory obtained by coupling the corresponding topological
quantum field theory (TQFT) to a single complex scalar field associated with this anyon. With these assumptions, we find the most general relativistic field theory for such a transition. Even though for a given TQFT and a choice of anyon, there are infinitely many such field theories, the transition theory depends on only a single additional integer parameter. We analyze all these theories, their global
symmetries, and their phases. In generic cases, the theory after the transition can be related to the original one via an Abelian hierarchy construction. In special cases, the theory after the transition is gapless, and with a particular deformation, it is related to the original TQFT by gauging an anomaly-free one-form global
symmetry. We also explore the enrichment of this setup by a global U(1)
symmetry. In some cases, enriching the original TQFT is incompatible with the full transition theory. Finally, we demonstrate our construction with many specific examples.
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Strongly Correlated Electrons
Conductivity scaling of the anomalous Hall effect in the altermagnetic semiconductor {\alpha}-MnTe
Sara Bey, Shelby S. Fields, Nicholas G. Combs et al. (+22 more)
{\alpha}-MnTe is a prototypical altermagnet exhibiting a strong anomalous
Hall effect (AHE), despite having a nearly vanishing magnetization. Lately, sample-to-sample variations of the amplitude of the AHE have raised concerns of a possible defect related origin, especially in thin films. Here, we study the AHE in {\alpha}-MnTe films grown on SrF2 that have the
crystal structure and m'm'm
magnetic point group
symmetry expected for bulk. By studying the scaling of the AHE with conductivity for those films and previously reported measurements in the literature, we find that sample-to-sample variations are well explained by a scaling law consistent with a hopping origin. Importantly, a comparison with other
magnetic semiconductors reveals the colossal amplitude of the AHE of {\alpha}-MnTe compared to its measured spontaneous magnetization from magnetometry and polarized
neutron reflectivity. Our findings address the important fundamental question of the origin of the AHE of {\alpha}-MnTe and further demonstrate the potential of altermagnets as promising spintronic materials.
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All authors Sara Bey, Shelby S. Fields, Nicholas G. Combs, Bence G. Márkus, Jiashu Wang, Liam Schmidt, Lincoln Curtis, Allecia Dodd-Noble, Alexander Poulin, Syed Mohammad Shahed, Resham Regmi, Mariia Holub, Phillipe Ohresser, Arun Bansil, Swastik Kar, Haile Ambaye, Valeria Lauter, László Forró, Cory D. Cress, Joseph C. Prestigiacomo, Nirmal Ghimire, Alberto de la Torre, Steven P. Bennett, Xinyu Liu, Badih A. Assaf
Statistical Mechanics · Cross-listed from quant-ph
Theory of Magic Phase Transitions in Encoding-Decoding Circuits
Piotr Sierant and Xhek Turkeshi
Quantum magic resources, or nonstabilizerness, are a central ingredient for universal
quantum computation. In noisy many-body systems, the interplay between these resources and errors leads to sharp magic phase transitions. However, the microscopic mechanism behind these critical phenomena is still an open question, especially since early empirical evidence showed conflicting results regarding their universality classes. In this work, we provide a comprehensive picture of magic phase transitions for the class of encoding-decoding
quantum circuits to resolve these ambiguities. We analytically show that the behavior of magic resources is fundamentally dictated by the chosen measurement protocol. When we fix, or post-select, the class of measurement syndromes, the magic transition inherits the universal features of the error-resilience phase transition in the
circuits. Interestingly, this clean transition survives even for fully random Haar encoders showing that it is a consequence of initial's state
retrieval, and not an artifact of the Clifford encoders. On the other hand, if we consider realistic Born-rule sampling, the intrinsic statistical fluctuations of a given syndrome measurement act as a relevant perturbation. This brings in strong finite-size drifts and an apparent multifractality, which end up altering the critical behavior of the system. We reveal that magic phase transitions are actually direct manifestations of error-resilience thresholds, rather than independent critical phenomena, reconciling conflicting observations from the earlier literature. Ultimately, our framework clarifies how the
quantum computational power can survive, or be irreversibly destroyed, due to the competition between scrambling, measurements, and errors.
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Mesoscale and Nanoscale Physics · Cross-listed from physics.optics
Tailored dissipation for directional transport in plasmonic ratchets
Anna Sidorenko, Jan Mathis Giesen, Sebastian Eggert et al. (+1 more)
We present a joint experimental and theoretical study of a ratchet implemented in arra ys of evanescently coupled plasmonic waveguides with tailored losses. In this setup the time-periodic dissipation is the only active mechanism and notably, we find better rectified transport and lower losses in the transmitted signal with increased local dissipation. Using Floquet theory, we uncover a driving regime that allows efficient directional tr ansport for suitable driving frequencies and loss rates, which are linked to linear qu asienergy bands with minimal losses. These regions are separated from non-resonant beh avior by sharp transitions with characteristic exceptional points in the spectrum. Direct experimental observation of the Floquet-dissipative ratchet effect using a comb ination of real- and
Fourier-space leakage radiation microscopy is provided.
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All authors Anna Sidorenko, Jan Mathis Giesen, Sebastian Eggert, Stefan Linden
Statistical Mechanics
Thermalization-Induced Entropy-Rate Representation of Internal Energy in a Damped Quantum Oscillator
Hyeong-Chan Kim and Youngone Lee
We study a harmonic oscillator weakly coupled to a thermal bath and evolving under the standard
quantum-optical master equation. For zero-mean Gaussian states,
entropy alone does not determine the internal energy because the latter also depends on nonequilibrium Gaussian structure. We show, however, that thermal relaxation yields the exact representation $ E=E(S,\dot S) $ for every mixed Gaussian state evolving under this thermal
quantum-optical master equation. Explicitly, \[ E(S,\dot S)= \frac{\omega\nu(S)}{\nu_{\rm th}} \left[ \nu(S)+ \frac{\dot S}{\gamma S'(\nu(S))} \right]. \] Once the thermal GKLS equation is assumed, no further expansion in the damping rate,
entropy rate, or distance from
equilibrium is made. The
entropy rate is not an alternative instantaneous state coordinate: it depends on the open-system dynamics and therefore carries information about the coupling to the bath. This is exposed by the isolated limit, where $\dot S=0$ for all Gaussian states and the representation no longer determines the energy. The result thus identifies an exact thermalization-induced dynamical energetic relation, distinct from rate dependence generated by an external driving protocol. We also describe an operational test based on time-resolved purity and energy measurements. At fixed frequency the bath only relaxes pre-existing squeezing. We therefore also consider frequency modulation, which can drive an initially thermal state away from the instantaneous Gibbs family by generating off-Gibbs Gaussian structure. Within a local Gaussian continuation, the bath then relaxes this driven deformation, providing a dynamical realization of the
entropy-rate dependence.
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Statistical Mechanics
Samuel H. Pickering and Bruno Bertini
The discovery of chaotic
quantum circuits with (partially) solvable dynamics has played a key role in our understanding of non-
equilibrium quantum matter and, at the same time, has helped the development of concrete platforms for
quantum computation. It was shown that solvability does not prevent the generation of chaotic dynamics, however, it imposes non-trivial constraints on the generated correlations. A natural question is then whether it is possible to gain insight into the generic case despite the latter being very hard to access. To address this question here we introduce a family of 'asymptotically solvable'
quantum circuits where the solvability constraints only affect correlations on length scales beyond a tuneable threshold. This means that their dynamics are only solvable for long enough times: for times shorter than the threshold they are generic. We show this by computing both their dynamical correlations on the
equilibrium (infinite temperature) state and their thermalisation dynamics following
quantum quenches from compatible (asymptotically solvable) non-
equilibrium initial states. The class of systems we introduce is generically ergodic but contains a non-interacting point, which we use to provide exact analytical results, complementing those of numerical experiments, on the non-solvable early time regime.
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Soft Condensed Matter
Active fluctuations induce buckling of living surfaces
Matteo Ciarchi, Andriy Goychuk and Erwin Frey
Active tissues exhibit tension fluctuations that are correlated in space and time. We study a minimal overdamped surface model in which such fluctuations enter as a zero-mean, multiplicative modulation of the local surface tension. Although the deterministic elastic dynamics (tension plus bending) stabilizes the flat state for all nonzero wave numbers, we find that sufficiently persistent active fluctuations generate positive ensemble growth rates for a finite band of
Fourier modes, leading to
stochastic buckling with wavelength selection. A non-Markovian theory based on the Novikov–Furutsu
theorem captures the instability threshold and unstable band observed in simulations.
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Materials Science
Resolving the Metastable Si-XIII Structure through Convergent Theory and Experiment
Fabrizio Rovaris, Corrado Bongiorno, Anna Marzegalli et al. (+10 more)
Silicon is the undisputed cornerstone of modern technology, with applications ranging from micro- and opto-electronics to
quantum technologies. Recently, the exploration of its allotropes has emerged as a pivotal frontier for engineering materials with tailored optical and electronic functionalities. High-pressure experiments have revealed several metastable silicon phases, among which is Si-XIII. First observed more than 20 years ago, this phase has remained structurally unidentified, representing a significant gap in our understanding of elemental silicon allotropy. In this work, a convergent methodology is employed combining advanced theoretical modeling with experimental characterization to finally resolve the long-standing structural assignment of Si-XIII. Guided by careful experimental observations, a structural model validated through first-principles optimization and systematically tested against multiple experimental signatures is constructed. All the fingerprints of this phase are rationalized by our proposed
crystal structure: interplanar spacings, Raman frequencies, thermodynamic stability, and kinetic pathways. These findings provide a crucial missing piece in the high-pressure phase diagram of silicon and demonstrate the power of integrating computational predictions with experimental validation to resolve complex structural problems in materials science.
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All authors Fabrizio Rovaris, Corrado Bongiorno, Anna Marzegalli, Mouad Bikerouin, Davide Spirito, Gerald J. K. Schaffar, Mohamed Zaghloul, Agnieszka Anna Corley-Wiciak, Francesco Montalenti, Verena Maier-Kiener, Giovanni Capellini, Antonio M. Mio, Emilio Scalise
Statistical Mechanics
Anomalous hydrodynamic fluctuations in the quantum XXZ spin chain
Takato Yoshimura, Žiga Krajnik, Alvise Bastianello et al. (+1 more)
The
quantum XXZ
spin-1/2 chain features non-Gaussian
spin current fluctuations in the regime of easy-axis anisotropy. Using ballistic macroscopic fluctuation theory, we derive the exact probability distribution of typical
spin-current fluctuations in thermal
equilibrium. The obtained nested Gaussian distribution is fully characterized by its variance which we analytically relate to the
spin diffusion constant and static
spin susceptibility, and compare with numerical simulations. By unveiling how the same mechanism which leads to anomalous charge current fluctuations in single-file systems manifests itself in the XXZ chain, our approach establishes the universal hydrodynamic origin of the observed anomalous fluctuations.
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All authors Takato Yoshimura, Žiga Krajnik, Alvise Bastianello, Enej Ilievski
Strongly Correlated Electrons · Cross-listed from hep-lat
Imprints of $U_A(1)$ chiral anomaly and disorder in the Dirac eigenspectrum of QCD at finite temperature
Ravi Shanker, Harshit Pandey and Sayantan Sharma
We perform a comprehensive study of the properties of Dirac
eigenvalue spectrum in QCD as a function of temperature on the
lattice. In addition to effects due to interplay between interactions and disorder inherently present in a many-body system, the Dirac spectrum also contains crucial information about the effective restoration of different subgroups of almost exact two-
flavor chiral symmetry in QCD. We calculate the infrared
eigenvalues of the overlap Dirac operator on 2+1
flavor QCD ensembles generated using domain wall
fermion discretization, on a large volume
lattice. From the normalized level spacing ratios, we identify those
eigenvalues that have intermediate level statistics, distinctly different from the majority in the bulk spectrum that follow universal level fluctuations similar to a random
matrix of Gaussian
unitary type. We provide an explanation of these intermediate level ratios in terms of a specific random
matrix model and quantify the correlation between these eigenstates and disorder in the gauge fields manifested in the renormalized Polyakov loop values. Whereas the existence of intermediate eigenmodes is intimately connected to the effective restoration of different subgroups of
chiral symmetry close to
chiral crossover transition, their origin can be traced to random uncorrelated disorder at higher temperatures when the $U_A(1)$ is effectively restored. We also, for the first time, calculate the Thouless conductance for the Dirac spectrum that quantifies the structural
rigidity of the eigenvectors, and use it as a diagnostic tool to understand the restoration of the anomalous $U_A(1)$ subgroup of
chiral symmetry and localization driven by disorder.
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Quantum Gases
Effective Three-Boson Interactions using a Separable Potential
Corinne Beckers, Jacques Tempere, Jeff Maki et al. (+1 more)
Effective field theories (EFTs) are widely used to study many-body systems by describing two-body interactions using zero-ranged contact potentials. However, when extended to three-body processes, these contact interactions lead to divergences due to the absence of an intrinsic length scale. In EFT, this is typically resolved by introducing a zero-ranged three-body interaction, which can be renormalized to make the low-energy physics independent of the short-distance physics. However, when the two-body potential has a finite range, such as in separable potentials, there is no need for such renormalization. In this work, we derive the integral equation for the three-body scattering amplitude for separable potentials, and solve it in the strongly-interacting regime. With our model, we retrieve the known analytic form of the scattering amplitude for inelastic scattering processes and formulate a new scaling law for elastic three-body scattering processes.
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All authors Corinne Beckers, Jacques Tempere, Jeff Maki, Denise Ahmed-Braun