Papers

Moiré multi-layers of transition metal dichalcogenides have been shown to exhibit optical responses that are endowed with a richness that is absent in single monolayers. Much of this can be attributed to the Moiré superlattice that modulates the electronic landscape of these heterostructures. Strongly coupled layer-hybridized excitons in $\text{MoSe}_2 / \text{WS}_2$ heterobilayers have been shown to exhibit enhanced optical nonlinearities. In this work we strongly couple layer hybridized excitons and trions in n-doped $\text{MoSe}_2 / \text{WS}_2$ heterobilayers inside an optical microcavity. We find that the additional Lindhard screening from dopant electrons and the formation of trions result in a strikingly non-monotonic nonlinear response. The absence of electron capture in the Moiré superlattice plays a crucial role, promising very large second-order nonlinearities. In this work, trion polaritons manifest as high velocity hot polaritons, reaching nominal diffusion lengths approaching 100 microns.

Understanding the relaxation dynamics of isolated quantum systems remains a central challenge in nonequilibrium physics. In this short review, we discuss recent experimental and theoretical advances in universal dynamics of turbulent Bose gases, with particular emphasis on nonthermal fixed points and wave turbulence in our experimental system at the São Carlos Institute of Physics of the University of São Paulo. We highlight the emergence of self-similar scaling behavior and its connection to particle and energy transport across momentum scales. In addition, we discuss an approach in which a differential equation has a universal scaling solution, providing a practical framework for extracting universal exponents from limited regions of the momentum distribution. Furthermore, we recap experimental observations of direct and inverse cascades in a three-dimensional trapped Bose–Einstein condensate, revealing distinct relaxation stages governed by universal scaling laws. These results demonstrate that turbulence plays a key role in far-from-equilibrium dynamics, offering a unified perspective on transport processes and thermalization in quantum many-body systems.

The magnetization dynamics of an all-garnet trilayer consisting of Y3Fe5O12/Y3Fe3Al2O12/Y3Fe5O12 (YIG/YIAG/YIG) is analysed. The two magnetic YIG layers, separated by a 4 nm thick paramagnetic YIAG layer, are coupled via dipolar interactions leading to the formation of hybrid magnon modes distinct from the modes found in a single YIG layer. The YIAG exchange-decouples the YIG layers while enabling lattice coherence, maintaining the low damping of the YIG. Both ferromagnetic resonance and micro-Brillouin light scattering measurements were used to characterize the sample and its hybrid dynamics, which showed excellent agreement with an analytical reciprocal space model of spin-wave dynamics and with micromagnetic modeling of a dipolarly coupled magnetic heterostructure.

We study equilibrium clustering in a finite one-dimensional lattice gas of $L$ sites with periodic boundary conditions, as a minimal model for adsorption and binding on small ring-like substrates. Using a grand-canonical formulation with nearest-neighbor coupling, we derive exact finite-size expressions for the mean occupancy, the mean number of domain walls, and the mean number of clusters. Building on exact $k$-site correlation functions, we further derive expressions for the mean number of clusters of size $k$ and for two complementary size statistics: the cluster-size distribution, and the site-weighted cluster-size distribution. These observables characterize how spatial organization changes across attractive (cooperative) and repulsive (anticooperative) interactions, and highlight finite-size and parity-dependent effects of the underlying lattice, the latter being particularly pronounced near half filling in small systems. To access larger lattices without enumerating all $2^L$ microstates, we also develop a cluster-based combinatorial formulation in which configurations are classified by cluster counts and sizes, reducing the effective state space to a set whose size scales with integer partitions, $\approx e^{\sqrt{L}}$, rather than with $\approx e^{L}$. Taken together, our results provide exact benchmarks for finite periodic systems and suggest experimentally relevant cluster observables that complement occupancy-based measures of cooperativity, with particular relevance for binding on ring-like substrates for biological assemblies.

We derive an effective orbital-lattice model with quantum $S=1$ degrees of freedom for transition-metal compounds, providing a microscopic understanding of cluster formation driven by the cooperative interplay of spin, orbital, and lattice degrees of freedom. Motivated by the trimerized phases observed in LiVS$_2$ and LiVO$_2$, we consider a triangular-lattice three-orbital system with two electrons per site occupying the threefold-degenerate $t_{2g}$ manifold. Starting from a multiorbital Kanamori-Hubbard Hamiltonian, we project the low-energy sector onto the local $S=1$ triplet manifold, in which two electrons occupy different orbitals according to Hund's coupling. The resulting effective model exhibits exchange networks whose geometry is determined by the orbital configuration. However, the orbital-driven exchange interactions alone do not stabilize the experimentally observed trimer phase. We find that by incorporating ionic lattice displacements that modulate transfer integrals and induce bond-dependent exchange couplings on shortened and elongated bonds, the phase competition is qualitatively altered, leading to the robust stabilization of a trimerized ground state within a fully quantum-mechanical framework. We further show that a simplified orbital-lattice model, in which the spin-exchange energy is replaced by effective bond energies, faithfully reproduces the essential ground-state properties of the microscopic model. This reduced description enables large-scale finite-temperature simulations and reveals a rich sequence of thermal phase transitions, including first-order, second-order, and Kosterlitz-Thouless transitions into distinct spin-, orbital-, and lattice-ordered phases.

Extending the holographic principle to de Sitter (dS) spacetimes remains one of the most vital open frontiers in quantum gravity, where a microscopic, bottom-up tensor-network framework that relates boundary quantum data to emergent de Sitter spacetime is still lacking. In this work, we first show the emergence of de Sitter spacetime from boundary entanglement by formulating a non-unitary continuous multi-scale entanglement renormalization ansatz (cMERA) for a concrete non-Hermitian critical fermion chain. Within this emergent spacetime, we analyze the associated geodesics and show that they act as extremal Ryu-Takayanagi (RT) surfaces undergoing a smooth timelike-to-null transition. Remarkably, we demonstrate that this continuum trajectory suggests a distinct tensor-network architecture in which the bond-counting contribution naturally truncates at the discrete timelike-to-null transition toward the deep infrared. In the resulting architecture, the null ray along the horizon is represented by zero-cost links, since the associated cut severs no tensor legs. This network structure successfully reproduces the logarithmic scaling of non-unitary critical entanglement entropy, offering a bond-counting picture for the de Sitter RT formula. Our results provide the long-sought dS/(c)MERA correspondence at the level of both emergent spacetime and discrete holographic entanglement.

Higher-order topological phases provide robust corner modes, but their use requires controllable creation, isolation, and transfer of individual modes and their superpositions. Here we demonstrate, using the two-dimensional Benalcazar-Bernevig-Hughes model as an example, that subchiral symmetry provides a general control principle for manipulating topological corner modes. The conventional chiral symmetry decomposes into four subchiral symmetries, each associated with one zero-energy corner mode. By selectively breaking these subsymmetries with controlled intercell hoppings, we reduce the fourfold corner-state manifold step by step to single isolated modes. We further design adiabatic protocols that transfer either a single corner state or a superposition of two corner states between selected corners, while preserving the relative phase in the latter case. Both numerical simulations and IBM quantum-processor implementations show that the proposed protocols can be executed with high fidelity, establishing subchiral symmetry as a route to programmable higher-order topological state manipulation.

According to the recent Wealth Thermalization Hypothesis (WTH) the wealth inequality in the world is described by the Rayleigh-Jeans (RJ) thermal distribution of interacting agents in a society with social stratification. In this concept, the wealth layers of society are associated with energy levels from a nonlinear dynamical system conserving two integrals of motion being total energy and probability norm. This leads to RJ condensation and the formation of a huge poverty phase of low wealth and a tiny oligarchic phase that captures a main part of total society wealth. This RJ phenomenon has similarities with self cleaning in multimode optical fibers and constraint driven condensation in various physical systems. We analyze real Lorenz and Pareto curves for wealth of households in countries and the world, Gross Domestic Product of countries, market capitalization of companies at stock exchange of Hong Kong, Shanghai, London, bitcoin transactions, world trade between countries and show that the WTH theory gives a good description of these curves. On the basis of this comparison we argue that the RJ thermal distribution provides a universal description of wealth inequality in the world.

Quantum zero-point effects have been long proposed to explain a well-known discrepancy between the low-temperature flow stresses of body-centered cubic metals and corresponding atomistic models of plastic flow. Previous investigations on quantum effects relied on empirical interatomic potentials, which poorly reproduce dislocation energy landscapes compared to density functional theory (DFT) calculations. Here, we revisit this problem using DFT and machine-learning interatomic potentials (MLIPs). We show that while quantum effects do contribute to dislocation glide at low temperature, their magnitude is much lower than previously reported, and insufficient to reconcile atomistic predictions with experiments. Our results thus reopen a long-standing question and challenge for predictive atomistic modeling, on a fundamental property of crystals.

We develop an effective-mass theory for spin-resolved transport and intersubband optical absorption in a finite semiconductor nanowire containing a uniform screw-dislocation-induced torsion. The central transport quantity is the band bottom of each torsion-dependent one-dimensional subband: torsion lowers this band bottom while an axial magnetic field resolves the two Zeeman branches, so that a spin-selective torsion interval opens when the Fermi level lies between the two branch minima. We distinguish this band-bottom transport threshold from the fixed-momentum transverse energy that governs the vertical intersubband optical transition, and obtain a design rule for the width of the spin-selective torsion interval that is linear in the Zeeman splitting in the small-splitting limit. Finite-size effects are incorporated by treating the active region as an open scattering region of length $L$ and radius $R$, with Fabry-Perot interference, radial boundary conditions, and surface-induced linewidth broadening. The spin-resolved response remains well defined when the effective linewidth satisfies $\Gamma_{\mathrm{eff}}\ll\Delta_Z$, a criterion quantified through polarization and conductance-contrast maps. In the optical sector, finite-radius intersubband absorption gives a torsion-tunable resonance in the THz range; surface boundary conditions shift the absolute resonance frequency and modify the oscillator strength, while, for the dominant unit-branch transition, the leading fixed-momentum torsional slope $\partial\omega/\partial\tau\simeq\hbar k_F/m^*$ is preserved. The resulting framework connects geometric torsion, spin-resolved mesoscopic transport, spin thermopower, and tunable intersubband absorption within a single open-quantum-wire model.

The three-dimensional repulsive Hubbard model is investigated using the strong-coupling diagram technique. For half-filling, the boundary between paramagnetic and antiferromagnetic states is determined for the range of the Hubbard repulsion $4t\leq U\leq12t$, where $t$ is the hopping integral between neighboring sites. Along this boundary, the density of states is calculated, and it demonstrates the Mott transition at $U\approx9t$. For $U\geq6t$ and half-filling, the density of states has the shape inherent in the strong electron repulsion, while for $U=4t$, its shape points to weak coupling. The dependence of the Néel temperature $T_{\rm N}$ on the electron concentration $\bar{n}$ is investigated for the cases $U=4t$ and $12t$. In the former case, $T_{\rm N}$ decreases monotonously with $\bar{n}$, while in the latter case, there is a plateau in the dependence near $\bar{n}=0.87$. The plateau is connected to a reconstruction of the density of states caused by an effective weakening of electron coupling due to electron depopulation. For $U=12t$ and half-filling, the magnetic critical exponent $\gamma\approx1.4$, which is close to the value in the Heisenberg model. Some features resembling the first-order phase transition, revealing themselves in a finite crystal, are discussed.

We derive a Lindbladian description of holographic Brownian motion in the high-temperature regime. Starting from the influence functional for a trailing string endpoint, we identify the corresponding quantum master equation and prove that it is completely positive and trace-preserving. We determine the coefficients of the Lindbladian explicitly for two holographic backgrounds: the BTZ black hole and the AdS$_5$ black brane, restricting in the latter case to the endpoint fluctuation along the $x^1$-direction. We then analyze the time evolution of phase-space moments, energy relaxation, and steady states.

Magnetism has long been attributed to localized d, f, and even p electrons with strong correlations, whereas s electrons exemplified by hydrogen are reactive and tend to have their spins quenched, making s-electron-derived magnetism and long-range ordered magnetic crystals seem unattainable. Here we report a low-Z ferromagnetic crystal H13@(BN)12 using first-principles calculations, where thirteen hydrogen atoms are encapsulated within a (BN)12 cage and magnetism originates from the 1s electron of the central hydrogen atom. The crystal remains stable under ambient pressure owing to chemical precompression. Notably, the central hydrogen atom retains a magnetic moment of 1 {\mu}B, with long-range magnetic order established through multicenter bonding within the H13 aggregate and the intercell B-B network, while the zero orbital angular momentum of s electrons renders spin-orbit coupling (SOC) negligible as expected. Electronic structure analyses reveal that the large cavity and central negative electrostatic potential of the (BN)12 cage localize the hydrogen 1s electron, preventing spin quenching. Interestingly, under 16 GPa compression, the system transforms into a nonmagnetic metallic state driven by delocalized electrons of the central hydrogen atom. This study opens a pathway for constructing s-electron-driven magnetic materials and lays the foundation for developing low-energy consumption magnetic devices without SOC.

Activated carbons are promising adsorbents for post-combustion CO2 capture due to their high surface area, tunable microporosity, and resistance to moisture and flue-gas impurities. Despite extensive equilibrium adsorption studies, the dynamic behavior of activated carbons under fixed-bed operating conditions relevant to post-combustion CO2/N2 remains insufficiently understood, particularly for renewable materials. In this work, the adsorption and separation behavior of CO2/N2 mixtures on a commercial coal-derived activated carbon (WS-480) and a biomass-based activated carbon (MSP700-A900CO2) is comparatively evaluated by combining experimental measurements and simulations. We examine the physicochemical properties of both materials, revealing that although WS-480 exhibits a higher of porosity, MSP700-A900CO2 contains a larger fraction of ultramicropores (<0.7 nm) and a broader distribution of oxygen-containing functional groups. These characteristics result in higher CO2 adsorption capacities for MSP700-A900CO2 in fixed-bed breakthrough experiments conducted under varying flow rates, temperatures and CO2 concentrations. We employ atomistic activated carbon models, augmented with surface functional groups as representations of WS-480 and MSP700-A900CO2, achieving close agreement with experimental adsorption data. The validated models are subsequently used to predict CO2/N2 separation under equilibrium and dynamic conditions, reproducing the experimental breakthrough behavior while providing molecular-level insight into the influence of pore structure and surface chemistry on adsorption performance.

Topological edge states are celebrated for their robustness against disorder, yet the interplay between disorder and system size remains poorly understood. We use large deviations theory as a framework to study finite-size effects beyond the central limit theorem. We analyze Lyapunov exponent fluctuations in the static and periodically driven disordered Kitaev chain and find an asymmetry in the large deviations statistics that makes stronger edge localizations of Majorana zero modes exponentially more likely than weaker ones. We demonstrate that this fluctuation asymmetry is not tied to the topological phase. This asymmetry endows topological edge states with an additional protection against disorder and persists across a broad class of disorder distribution. We show how to use our framework to find the minimum system size required to satisfy topological quantum computing constraints.

Some topological phases of matter are called fragile. They can be trivialized by adding additional valence bands and do not generically host protected gapless boundary states. Here we establish a fragile topological index with a bulk signature: it guarantees the presence of gap closing points in the bulk band structure of systems with both time-reversal and twofold rotation symmetry. This result extends the established use of the Euler class in diagnosing the presence of Dirac cones for general two-dimensional systems with a combination of time-reversal and twofold rotation symmetry, to the case of nonmagnetic materials obeying both symmetries individually. The abundance of natural nonmagnetic materials with these symmetries renders the topological invariant practically useful, despite its fragility. We demonstrate this by applying first-principles calculations to five materials and finding that all of them host Dirac points identified by the invariant, suggesting its widespread applicability. Our results thus provide a robust spectroscopic signature of fragile topology in nonmagnetic systems which can be directly accessed in experiments on practically relevant materials. Furthermore, they enable an alternate method for finding Dirac cones in ab-initio simulations, and may be used as a route towards identifying materials with nonlinear transport properties.

We develop a replica-based framework for the scaled cumulant-generating functional of the empirical spectral distribution function $i_C$ of diluted Hermitian random matrices. Within a replica-symmetric saddle-point assumption, this construction yields a candidate rate functional for fluctuations of $i_C$. As an illustrative application, we consider adjacency matrices of unweighted Erdős-Rényi random graphs with mean degree $c$. We derive explicit expressions for the first two cumulants of $i_C$, indicate how higher cumulants can be obtained from further functional derivatives, and compute the rate function of Fourier coefficients, equivalently of selected linear spectral statistics. The replica-symmetric predictions are tested against exact numerical diagonalization and show good agreement in the accessible fluctuation regime. The approach provides a basis for studying rate functionals of spectral observables in sparse random matrix ensembles.

The microscopic origin of chirality-induced spin selectivity (CISS), a phenomena where chiral molecules connected to a magnetic electrode show large spin-dependent conductance asymmetry even in ambient temperature, still remains an open question. Most of the existent theories are based on some sort of effective spin-orbit coupling or interfacial scattering, which do not provide satisfactory explanations for experimental observations such as the magnitude of spin polarization or the length dependence of the effect. We propose an alternative theoretical framework rooted in an intrinsic molecular contribution that shows a robust CISS effect and scales with the length of the molecule. The mechanism is based on the emergent molecular magnetic moment (MOM), which can produce experimentally observed point-symmetric I-V curves without violating the Onsager-Casimir reciprocity relation. The MOM has an intrinsic component that is governed by the chirality of the molecule and leads to finite CISS magnetoresistance and magnetochiral conductance asymmetry (MChA) that are even in bias voltage. By decomposing the MOM into its Fermi sea and Fermi surface components, we show that under strong bias, the MOM can be dominated by the Fermi surface contribution, which causes a sign change in the MChA leading to a behavior similar to that of electric magnetochiral anisotropy (eMChA). Finally, we analyze the effect of a magnetic field within the same framework, which may provide better insight into the crossover between CISS and eMChA.

Photonic higher-order topological insulators (HOTI) are characterized by a hierarchy of topologically-protected states with different dimensionalities, making them especially interesting for potential applications that combine strong localization of electromagnetic fields and their robust waveguiding. However, their practical implementation often requires expensive processing techniques and is limited by accessible material parameters. In this paper, we demonstrate that a radio-frequency photonic HOTI can be implemented as a metasurface composed of split-ring resonators with couplings between dipole and quadrupole modes. We verify, by numerical simulations and experimentally at frequencies of 1.5-1.7 GHz, that a proposed metasurface supports corner- and edge-localized states. Our results reveal a scalable and easily reconfigurable GHz-range platform that employs printed circuit board technology, thus making crucial steps required for further experimental studies of photonic HOTI and the development of their microwave applications.

Realizing conditional quantum operations, e.g., quantum gates, for quantum computing and simulation requires controlled interactions between particles. Often, these interactions depend on the interparticle distance, and accordingly, an uncertainty of the relative particle position may translate into gate infidelities. We consider here a quantum computing platform based on an array of neutral atoms and present a method that allows to reduce the uncertainty of all interatomic distances. Our approach exploits the coupling between atomic motion and stroboscopically excited atomic Rydberg states. It allows to collectively squeeze the modes corresponding to interatomic displacements, thereby reducing distance fluctuations down to a fraction of the motional vacuum state. Furthermore, the method permits the creation of non-classical states with substantial Wigner negativity. These correlated states may allow reducing motional decoherence, increasing gate fidelity, and potentially yield a resource for quantum-enhanced metrology.

Altermagnetism as a new concept in condensed matter physics is currently being thoroughly investigated. Despite the absence of macroscopic magnetization, altermagnets host a hidden spin order whose direct detection remains a challenge. Here we report on the observation of electric and magnetic dipole forbidden optical second-harmonic generation (SHG) in the altermagnet CoF$_2$ with a centrosymmetric lattice and spin order. We demonstrate that below the Néel temperature $T_N = 38$ K the SHG signal is sensitive to the ferrotype magnetic octupole $\mathbf{\mathcal{O}}^M$ which is the order parameter in the antiferromagnetic phase. By combining polarization-resolved SHG experimental data and a phenomenological symmetry analysis, we show that the altermagnetic spin structure of CoF$_2$ enables a ferroic-octupole-induced electric-quadrupolar nonlinear polarization $\mathbf{P}^{2\omega} = \mathrm i\varepsilon_{0}{ }^c\mathbf{\chi}^{(3)}(\mathbf{\mathcal{O}}^M) :\mathbf{E}^{\omega} \nabla \mathbf{E}^{\omega}$. The temperature dependence of SHG reveals a phase transition at $T_N$ confirming the spin origin of the observed signal. The SHG response is resonantly enhanced by a coherent three-photon process caused by the electronic $d$-$d$ transitions of the Co$^{2+}$ ion. Model calculations of SHG polarization rotational anisotropies and temperature dependencies give a reasonable agreement with experimental data, proving the disclosed nonlinear contribution. Our results establish SHG as a novel sensitive tool of ferroic-octupolar spin ordering and highlight the potential of CoF$_2$ and other altermagnets for further nonlinear optical investigations and applications.

Magnetic behavior across Fe$_2$O$_3$ polymorphs varies widely despite identical chemistry, highlighting crystal architecture as a key determinant of exchange topology, magnetic anisotropy, and ultimately magnetic order. Here, using neutron and synchrotron X-ray diffraction, we establish the magnetic ground state of the poorly understood bixbyite $\beta$-Fe$_2$O$_3$ polymorph and uncover the structural origin of its strong frustration. Below the Néel temperature, a noncollinear antiferromagnetic state emerges through activation of the $mH_1^{+}$ irrep at the H-point [$\mathbf{k}=(1,1,1)$] and the antitranslation $(1'|\tfrac{1}{2},\tfrac{1}{2},\tfrac{1}{2})$, breaking the body centering and yielding two interpenetrating primitive cubic magnetic subcells with inverted moments and nonpolar type-IV symmetry. Under exclusively antiferromagnetic Fe$^{3+}$-O-Fe$^{3+}$ interactions, $\beta$-Fe$_2$O$_3$ exhibits a large frustration index ($f \approx 7.56$). This behavior originates from the intrinsic geometry of the bixbyite lattice: two magnetic sublattices with distinct point symmetries and anisotropy constraints are embedded in a three-dimensional exchange network containing interconnected triangular and hexagonal motifs. In $\{111\}$ planes, Fe2 ions form hexagonal rings interconnected by frustrated triangular units, while locally Ising-like Fe1 ions occupy the ring centers. Our results thus identify the bixbyite architecture as a promising general platform for frustrated noncollinear magnetism. Extending this structural framework to other magnetic transition-metal or 4$f$ ions opens a materials space for engineering competing exchange interactions and anisotropies, potentially stabilizing new noncollinear and field-tunable magnetic states.

Heat conduction in semiconductor crystals is fundamentally governed by the linearized Peierls-Boltzmann equation (LPBE) for phonon transport, that arises out of a kinetic theory for phonon quasiparticles. Yet, continuum theories such as the Fourier's heat diffusion, weakly quasiballistic and hydrodynamic heat equations are often used to explain the experimental observations of heat flow in these materials. Here, we show that a systematic reduction of the LPBE into such equivalent continuum descriptions are possible only for the limiting values of a set of generalized Knudsen numbers. We further show that all of these continuum heat flow regimes, along with the ballistic heat flow, can be described by a single continuum equation for the temperature field that originates from the eigenmode analysis of the LPBE, thus offering a unified picture of all possible heat flow regimes in semiconducting crystals. Using quantitative examples on twenty three technologically important semiconductors, we show that several previously-unidentified features of the non-Fourier heat flow regimes emerge from this generalized Knudsen number framework such as (1) the mutual exclusivity of the weakly quasiballistic and the hydrodynamic heat flow regimes, (2) length-dependent velocity of the hydrodynamic second sound temperature wave and a characteristic heating length for the strongest hydrodynamic second sound, (3) characteristic frequency-domain temperature response distinguishing the hydrodynamic second sound from the ballistic heat flow regime and, (4) a new non-oscillatory signature of transient hydrodynamic heat flow. Our work formally bridges the continuum and the particulate descriptions of heat flow, and provides insights into the important signatures of temperature dynamics in each of these heat flow regimes, that will aid in their unambiguous experimental observations in the future.

We propose a minimal model for chirality-induced spin selectivity (CISS) in dc transport through insulating chiral molecules, based on quantum tunneling and interaction-induced spin splitting. As a concrete realization of the latter, we consider a weak Zeeman interaction of the particle spin with the current-induced magnetic field, recently shown to occur in helical molecules. We show that quantum tunneling, combined with dissipation, amplifies the effect, so that even such a small spin-dependent perturbation can yield spin polarizations on the order of 100% across a wide range of applied bias voltages. Furthermore, our tunneling scenario naturally reproduces the characteristic CISS symmetry of the current-voltage dependence – namely, the invariance of the spin-polarization sign under reversal of the current direction – while fully respecting Onsager's reciprocity relations.

We propose a spin-wave phase shifter controlled using a domain-wall racetrack. The concept is demonstrated using micromagnetic simulations of a Permalloy domain-wall racetrack placed above a YIG film. The stray field from pinned domain walls modifies the internal magnetic field in the YIG region under the racetrack. This leads to a local change of the spin-wave wavelength and thereby enables control of the phase accumulated by Damon-Eshbach spin waves propagating through the region. Moving domain walls on the racetrack, the same physical structure can provide phase shifts of up to +/-90 degrees, without changing the waveguide geometry. A model based on the semiclassical approximation confirms that the phase shift is dominated by the domain-wall-induced stray field. These results suggest a route toward a compact programmable spin-wave phase shifter for interference-based magnonic circuits for information processing. Moreover, the demonstrated magnonic device integration with a magnetic domain-wall racetrack can lead to its application in in-memory computing.

We investigate the relationship between volumetric and surface growth within a recently proposed optimization-driven framework for linearly elastic solids. In this approach, growth is not prescribed through an evolution law; instead, the growth distribution is determined as the solution of a constrained optimization problem. Focusing on processes driven by the minimization of the work performed by external loads in one-dimensional and axisymmetric settings, we derive explicit analytical solutions for the resulting growth distributions. Although growth is initially formulated as a volumetric process through a distributed growth strain tensor, we show that the optimal growth distributions are singular and concentrate on boundaries or internal interfaces. These results provide a variational mechanism through which, under certain conditions, surface growth is selected as the optimal realization of volumetric growth.

Relaxation dynamics of supercooled liquids approaching glassy arrest remain a central challenge in integrated electronic architectures, where conventional rheometry becomes incompatible. Here, we demonstrate that an ambipolar PdSe$_2$ field-effect transistor functions as an electrical probe capable of resolving ion-specific relaxation dynamics in fragile ionic glass formers and semiquantitatively inferring rheological parameters within an operating device environment. Temperature evolution of the transfer curve hysteresis and time-resolved current transients under ionic-gate pulse reveal a non-Arrhenius fragile slowdown. We track the continuous reduction of dynamically equilibrated liquid regions approaching the glass transition through an electrically accessible quantity $p_\text{eq}(T)$, quantifying the fraction of the mobile ions able to relax within the experimental timescale. Upon cooling, $p_\text{eq}$ collapses sharply as mobile regions fragment into percolating fractal clusters, consistent with a reduction of configurational entropy predicted for fragile glass formers. This approach enables temperature-dependent scaling of viscosity and extraction of characteristic temperatures marking the ergodic-to-nonergodic crossover, within a solid-state device architecture where conventional rheological characterization is inapplicable. Further, polymer confinement of the ionic liquid shifts these characteristic temperatures upward, demonstrating the sensitivity of this method to structural constraints imposed by the polymer matrix.

Fractional quantum Hall (FQH) colliders measure anyon exchange phases via time-domain braiding, but the $\nu=2/5$ state exhibits an intriguing negative Fano factor, challenging theoretical predictions. Here, we study the effect of inter-edge interactions in a multi-mode FQH collider. We demonstrate that the resulting fractionalization into eigenmodes causes the anyon beam to decompose into correlated and uncorrelated components, which have very distinct behavior in terms of time-domain braiding. We show that the uncorrelated part dominates in the long-junction limit, reversing the tunneling current sign and reproducing the observed negative Fano factor at $\nu=2/5$. Our results highlight the role of interactions and provide a robust interpretation of anyonic braiding in multi-mode systems.

Motivated by permutation statistical models arising in random tensor networks, we study permutation models on a Cayley tree whose variables take values in the symmetric group $\Sn$. The pair interaction is assumed to depend only on the cycle type of the relative permutation. Then the Boltzmann weight is written as a class function on $\Sn$. This property diagonalizes the edge convolution operator in irreducible representation sectors. As a result, the linear stability of the uniform paramagnetic cavity solution is controlled by the character eigenvalue ratios. For cycle-factorized weights, these eigenvalues can be expressed as specializations of Schur functions. We derive the instability criteria and also verify their validity by comparison with direct numerical iterations of the cavity equation.

Unlike de Haas–van Alphen measurements, heat-capacity magneto-quantum oscillations directly probe the oscillatory bulk quasiparticle density of states. Here, we report the observation of MQOs in V$_2$Ga$_5$ single crystals studied via highly sensitive ac calorimetry. The strongest MQO signal is observed for a magnetic field applied along the vanadium chains, in excellent agreement with de Haas–van Alphen magnetization data. A single dominant frequency of 126.6 T resolved by fast Fourier transform confirms the true bulk origin of the elliptical $\gamma$ Fermi-surface pocket located near the Z point of the Brillouin zone. The angular dependence of the FFT frequency closely tracks the anisotropy of the $\gamma$ pocket, as supported by first-principles calculations. Analysis of the temperature- and field-dependent MQO amplitudes allows the precise determination of the effective cyclotron mass, Dingle temperature, quantum relaxation time, carrier mobility, and electron mean free path. Furthermore, we demonstrate that the net Berry flux is invariant with respect to the magnetic-field orientation, as a consequence of a conserved hybridization phase twist within the $\gamma$ pocket. These findings establish ac calorimetry as a powerful macroscopic probe of topological orbital hybridization in complex intermetallics.