Papers

Proteins and nucleic acids form non-Newtonian liquids with complex rheological properties that contribute to their function in vivo. Here we investigate the rheology of the transcription factor NANOG, a key protein to maintain embryonic stem cell pluripotency. We find that at high concentrations, NANOG forms macroscopic aging gels that are dependent on its intrinsically disordered domain. By combining molecular dynamics simulations, mass photometry and Cryo-EM, we also discover that – in contrast with unbounded condensates formed by other intrinsically disordered proteins – NANOG forms self-limiting micelles with exposed DNA-binding domains. We show that these micelles can stabilize DNA entanglements and in turn modulate DNA dynamics. Based on our findings, we conjecture that NANOG may contribute to regulate gene expression by creating local gel-like environments that restrict genome dynamics and that its aging may ingrain mechanical memory in gene regulatory networks.

Correlated real-time dynamics in large, spatially inhomogeneous quantum systems remain difficult to access with nonequilibrium many-body methods. Two-time nonequilibrium Green functions (NEGF) retain dynamical correlations but their computational runtime grows cubically with the number of time steps $N_\mathrm{t}$. This scaling bottleneck could recently be overcome by introducing the G1–G2 scheme that is linear in $N_\mathrm{t}$, but requires propagation of a two-particle correlation function and may suffer from numerical instabilities. This has restricted simulations to small systems with $N_\mathrm{b} \sim 10^2$ basis states. Here we introduce a quantum-fluctuation formulation of nonequilibrium Green functions, denoted $\delta$NEGF, that represents dynamical two-particle correlations through fluctuations of field-operator products, $\delta \hat G$. This guarantees stable dynamics by preserving the positivity of the reduced density matrices, avoids the explicit storage of the two-particle Green function, and reduces the propagation to a finite ensemble of Hartree-Fock-like trajectories. Combined with a stochastic low-rank decomposition of the correlation functions, the method retains time-linear scaling while extending dynamical $GW$ and particle-particle and particle-hole $T$-matrix simulations to basis sizes of order $N_\mathrm{b}\sim 10^4$. We benchmark $\delta$NEGF against exact and HF-GKBA results for lattice systems, finding stable correlated dynamics also at strong coupling. We further demonstrate large-scale simulations of diffusion in two-dimensional Hubbard lattices and ultrafast relaxation in graphene nanoribbon heterostructures with long-range Coulomb interactions. These results establish $\delta$NEGF as a scalable route to dynamical self-energy simulations of large, spatially inhomogeneous correlated quantum systems beyond the reach of existing NEGF implementations.

Nonequilibrium thermodynamics is governed by the dynamical partition function, and its computation in high-dimensional continuous-state dynamics is a longstanding challenge. The Feynman-Kac formalism provides a rigorous representation for generating functions of arbitrary path observables; however, practical evaluation beyond low dimensions or the weak-noise limit is hindered by the curse of dimensionality and the exponentially growing replica demands of trajectory-based methods. Here we develop a mesh-free neural variational framework that realizes the Feynman-Kac theorem with generative flow models, recasting tilted stochastic evolution as a time-dependent optimization problem. This approach enables the direct computation of both finite-time and asymptotic trajectory thermodynamics in a unified manner. The method applies to general observables, enabling the evaluation of work, entropy production, and current fluctuations. We demonstrate the accuracy and scalability of this method in various nonequilibrium systems including high-dimensional cases.

Evaporating sessile droplets are usually treated as capillary objects, but droplets generated by routine handling can carry tens to hundreds of picocoulombs of electric charge. Here we combine Faraday-cup charge measurements with optical imaging to determine how such charge evolves as water droplets evaporate on dry polymer substrates. A zero-time protocol shows that a reproducible initial charge is preserved on poly(methylpentene) (PMP), whereas PDMS, SOCAL-coated surfaces, and polystyrene either exchange, dissipate, or inject charge on contact. On PMP, ensemble-resolved measurements reveal two regimes: the charge remains nearly constant during early evaporation and then decreases abruptly once the droplet reaches a small-volume state. This charge collapse coincides with spontaneous lateral translation rather than jetting or breakup. A Rayleigh-normalized analysis, including a spherical-cap stress correction and measured contact-angle retention scale, shows that motion occurs only after evaporation drives the droplet into a high electro-pinning state. High-speed imaging and kinematic analysis support a picture in which the subsequent motion is governed by repeated contact-line depinning and re-pinning: the total distance traveled is strongly affected by dry-surface pinning, whereas the peak translational velocity serves as a more robust indicator of the discharge strength. These results identify a dry-substrate mode of evaporation-driven electrostatic relaxation, distinct from Coulomb fission on lubricated surfaces, in which substrate electrostatic passivity enables charge retention, droplet geometry selects the instability onset, and whole-droplet translation provides the charge-release pathway.

We investigate spin polarisation and low-energy excitations in fractional quantum Hall (FQH) states using cavity-polariton spectroscopy of high-mobility GaAs quantum wells. By measuring the optical coupling strength of interband Landau-level excitations over the range $1/3 \le \nu \le 1$, we extract the spin polarisation of the electron system as a function of filling factor. Complete suppression of the oscillator strength of the lowest energy excitation, characteristic of singlet trion formation in fully polarised systems, is reported for the first time in this regime. At large magnetic fields, fully polarised FQH states exhibit symmetric depolarisation away from their quantised fillings, analogous to Skyrmionic behaviour near $\nu=1$. The depolarisation follows an empirical law $S=\nu^*$, where $S$ is the number of spin flips per added magnetic flux quantum and $\nu^*$ the effective Composite Fermion filling factor. We interpret this behaviour as evidence for Minimal Fractionally Charged Skyrmions (MFCS) formed from bound spin-flip and quasiparticle excitations.

As new observational technologies reveal increasingly detailed properties of neutron star surfaces, the demand for accessible and extensible theoretical modeling tools continues to grow. We present UnReal-B, a real-space Density Functional Theory solver for one-dimensional chains of matter in extreme magnetic fields $B \approx 10^{12} - 10^{15},\mathrm{G}$. By employing the adiabatic approximation, UnReal-B, provides a streamlined numerical framework for calculating the electronic structure of strongly magnetized condensed matter. The solver is benchmarked against published results for several astrophysically relevant elements, demonstrating excellent agreement while maintaining a comparatively simple and transparent implementation. Released as open-source software, UnReal-B facilitates reproducible and community-driven investigations of neutron-star surface matter and provides a foundation for future developments motivated by emerging observational constraints.

Strongly correlated two-dimensional systems provide compelling platforms for investigating exotic quantum phenomena. Niobium chloride (Nb$_3$Cl$_8$), a single-band Mott insulator, exhibits a remarkable out-of-plane polarization in its topmost layer that oscillates with layer parity, manifesting as an odd-even effect. Using atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM), this layer-parity-dependent polarization can be effectively characterized through surface morphology and potential mapping, enabling the unambiguous identification of different surface phases. We then fabricated dual-gate Hall devices by coupling different surface phases of Nb$_3$Cl$_8$ with monolayer graphene to investigate how the topmost-layer out-of-plane polarization influences interfacial coupling and the resulting transport behavior. Our results reveal significant phase-dependent variations in charge transfer, carrier densities, and hybridization gaps (25.2 meV for Phase 1 and 30.0 meV for Phase 2). Density functional theory calculations corroborate these experimental findings, showing that distinct out-of-plane polarizations in the topmost layer lead to different orbital overlaps and interfacial coupling strengths. These findings highlight the critical importance of surface polarization and orbital orientation in engineering the properties of strongly correlated van der Waals heterostructures.

A dynamical equivalent of the bulk-boundary correspondence has been suggested to occur in one and two dimensional topological models following sudden quenches. Depending on the topological invariant of the time evolving and initial phases involved large boundary contributions to a dynamical free energy occur. Moreover they occur periodically between the critical times at which this dynamical free energy becomes non-analytic, i.e.~at dynamical quantum phase transitions. At these critical times the eigenvalue spectrum of the Loschmidt matrix which underlies the dynamical free energy closes its gap. The boundary contributions are understood to be due to zero-modes or in-gap bands of this matrix, forming a close analogy with equilibrium topological models and their edge modes. The exact cause of this phenomena and its generality remain unknown. In this article we test the dynamical bulk-boundary correspondence for a complicated two dimensional topological superconductor with a rich phase diagram, allowing quenches between many different Chern numbers. We show that there is no straightforward correspondence between the equilibrium phases quenched between and the dynamical bulk boundary correspondence. Furthermore the correspondence can depend on the orientation of the edges, suggesting a possible weak topological variant.

High-entropy materials are complex, multifunctional materials that have reshaped the design of advanced functional materials. Their chemically diverse compositions enable access to a broader compositional space than conventional solid solutions, while simultaneously posing significant challenges for fundamental structure property understanding. In this study, we introduce a new highentropy spinel oxide with an exceptionally low coercivity of 1.8 Oe at room temperature, among the lowest reported for bulk spinel oxides, and a high electrical resistivity (1560 ohm-cm). Neutron powder diffraction (NPD) and magnetic measurements reveal long-range collinear ferrimagnetic ordering (k = 0,0,0) with a transition temperature at 420 K. This rare combination of ultra-soft magnetic behavior, robust ferrimagnetic ordering well above room temperature, and high resistivity highlights its strong potential as an advanced soft-magnetic oxide for low-loss, high-frequency applications. Furthermore, X-ray absorption spectroscopy (XAS), Mossbauer spectroscopy, and NPD analyses were combined to determine the cation distribution and site selectivity across the tetrahedral and octahedral sites of the complex structure.

Chiral plasma appears in several areas of physics, historically starting from primordial plasma in the early Universe, then in quark-gluon plasma produced in heavy ion collisions, and, more recently, in Dirac and Weyl semimetals. The major signature of the plasma is the non-conservation of the axial current due to the chiral anomaly and the emergence of new, anomaly-induced transport phenomena. In this paper, we study the plasma exposed to arbitrarily strong constant magnetic and weak electric fields. Employing all-order gradient resummation, we write down constitutive relations for electric and axial currents parameterized by thirteen momentum- and magnetic- field-dependent transport coefficient functions. The latter are computed utilizing a theoretical lab for a realistic plasma, namely a holographic $U(1)_V \times U(1)_A$ Maxwell–Chern–Simons theory in Schwarzschild–AdS$_5$, in the probe limit. As an application, we revisit the phenomena of negative magnetoresistance and chiral magnetic waves, beyond the naive hydrodynamic limit.

We reconsider the Hawking–Page transition using the common thermodynamic vector field whose zeros include the Davies and Hawking–Page points. In the elementary AdS branch their winding numbers are $w_{\rm D}=-1$ and $w_{\rm HP}=+1$, so the pair has zero total charge but a non-zero signed first moment. After normalization by the Davies scales this moment gives the familiar universal ratios $C_S$ and $C_T$; in four dimensions $C_S=2$ and $C_T=2/\sqrt{3}-1$. We check the construction for Schwarzschild–AdS, grand-canonical Reissner–Nordström–AdS, charged non-rotating black holes in arbitrary dimension, and Kerr–AdS at fixed angular velocity. The same reduced geometry gives a barrier $B=1/3$ in four dimensions and $B(d)=1/[(d-1)(d-3)]$. Finally we propose a formulation involving a defect-resolved version for categorical or non-invertible symmetry sectors.

Altermagnets (A$\ell$Ms) are spin-compensated materials in which opposite-spin sublattices are connected by a symmetry that causes a spin splitting in their elementary excitations. As there is a strong effect of altermagnetism on domain wall properties, it is quite natural to also expect an enrichment of the physics of magnetic excitations at A$\ell$M domain walls. Here, we consider the propagation of spin eigen-excitations along domain walls in easy-axial $d$-wave A$\ell$Ms. Investigating the presence of bound states localized on a domain wall, we find that the effect of the A$\ell$M on the bound states strongly depends on the orientation of the domain wall relative to the crystallographic directions. If the domain wall is oriented along a nodal direction [100] or [010], A$\ell$M does not change the number of bound states; however, it leads to a nonlinear dispersion and a tilt of the wavefront. The effect of A$\ell$M is strongest when the domain wall is oriented along the directions [110] or [$\bar{1}$10], i.e., along the directions of the strongest A$\ell$M splitting in the magnon spectrum. In this case, (i) the additional gapped bound states appear, (ii) degeneracy of the eigenstates with respect to their polarization (right-handed or left-handed precession of the Néel vector) is removed, and (iii) the localization area of the bound states strongly depends on the eigenfrequency. The latter may lead to strong localization of the bound state at the domain wall. We further consider the influence of a static magnetic field that is applied along the easy axis, and find that the magnetic field induces an asymmetry between the localization regions on opposite sides of the domain wall and sets an upper limit on the absolute value of the propagating eigenstate's wave vector.

The manipulation of localization in quasiperiodic systems by mobility edges or localization transition holds significant physical importance. In this letter, we demonstrated that the dissipation can induce the emergence of anomalous mobility edges and extended-localized transition in emitter-cavity arrays controlled by quasiperiodic potentials. Specifically, we observe that the localization properties of emitters is governed by the nature of quantum bound states, either discrete or embedded in continuum, providing a unified mechanism linking the emitter-photon bound physics to quasiperiodic criticality. Depending on the bound state discrete or continuumlike, the induced effective excitation hopping exhibits either exponentially decaying or sinusoidally oscillating, giving rise to the formation of localized or critical states, respectively. Through a generalized duality transformation, we analytically determine the anomalous mobility edges and the critical strength of potential, enabling the construction of a full phase diagram. The study reveals that the physical characteristics of cavity exert a significant influence on excitation localization. Therefore, the manipulation of excitation localization can be achieved solely by adjusting the cavity fields.

Many nanoscale magnetic imaging techniques are constrained by the maximum magnetic field that can be applied during measurements, due to geometrical limitations or interactions with the probe or the detected signal (e.g., electrons). Here, it is demonstrated that sample-integrated metamaterial-inspired magnetic flux concentrators (MFCs) locally amplify magnetic fields, allowing observation of magnetization processes beyond instrumental limits. Micrometer-sized MFCs fabricated directly on the samples are tested in photoemission electron microscopy experiments employing X-ray magnetic circular dichroism as magnetic contrast mechanism. At low applied fields, substantial amplification factors enable observation of magnetization reversal in a chain of magnetite nanoparticles synthesized by magnetotactic bacteria at an applied field of 8 mT, substantially smaller than the 50 mT predicted by simulations in absence of MFCs. At higher fields, the field enhancement extends the accessible field range by a factor of five, enabling for the first time, imaging of the field-dependent magnetic domain structure evolution of an isolated giant magnetofossil. Finally, we show how MFC geometry and material parameters can be tuned to optimize performance considering sample and experimental constraints, providing a tunable and broadly applicable strategy for extending the accessible field range in a wide variety of nanoscale magnetic imaging techniques.

"Infinite layer" nickelates ${\cal R}$NiO$_2$ (${\cal R}$=rare earth), having empty apical O sites, become superconducting upon hole doping, stimulating research into the related sequence Nd$_{n+1}$Ni$^{+p}_n$O$_{2n+2}$, formal charge state $p$=1+$\frac{1}{n}$, $n$=2,3,4,...., with the $n$=5 member being found to be superconducting. The two layer system La$_3$Ni$_2$O$_{7-\delta}$, with $\delta$=0,$\frac{1}{2}$,1 ($p$=2.5,2,1.5) approaches the peak in the nickelate superconducting dome but shows no superconductivity. Newly reported La$_3$Ni$_2$O$_5$F reaches the Ni$^{1+}$ goal while, as we show, introducing a partially occupied electron band $E^*$, based on an interstitial density that extends over the three open "apical" layers and leads to a single cylindrical electron Fermi surface giving self-doping. The commonly inert Ni $d_{xz},d_{yz}$ orbitals partner with interstitial $E^*$ to provide an incipient non-analytic Dirac point, with the critical point being reachable by pressure or further F insertion. The $E^*$ electron cylinder and the conventional Ni $dp\sigma$ hole carriers combine to provide a two-fluid dichotomy of hole and electron quasiparticles, affecting normal state properties that should verify the dichotomous aspect of transport.

It has been argued that the polar phonon modes of two-dimensional (2D) materials should show a linear dependence close to the Brillouin zone center due to the reduced problem dimensionality compared to a three-dimensional crystal, leading to a vanishing LO-TO splitting. Revisiting this question using a mirror-charge framework derived from classical electrostatics, we show that it is not always true: with perfectly-reflective dielectric interfaces, it is possible to recover a LO-TO splitting, or an equivalent phenomenon for the out-of-plane modes. Effectively, the dispersion of polar phonon modes is governed by optical-like constructive and destructive interferences of the source potential with its reflection at the dielectric interfaces. This work highlights the critical role of dielectric boundary conditions to understand phonon-related properties in 2D materials.

We study interaction-driven ultrafast dynamics in finite graphene flakes following an optical pump quench in an interacting tight-binding model. By comparing exact real-time evolution with simulations restricted to particle-hole excitation subspaces, we assess when relaxation can be captured by low-order many-body processes and when this is not sufficient. The single-particle orbital entropy provides a compact diagnostic for dynamic correlation growth. For the systems studied here, periodic graphene flakes are well described by low-order excitations, whereas confined geometries require substantial higher-order contributions even for relatively small interaction strengths. The quench protocol combines simple initial-state preparation with strongly correlated dynamics, identifying a promising benchmark problem for future quantum-computing simulations.

Energy Dispersive X-ray (EDX) tomography in Scanning Transmission Electron Microscopy (STEM) enables 3D compositional and elemental mapping at the nanoscale, but its use is limited by restricted tilt ranges and low-dose conditions required to avoid beam damage. Limited-angle acquisition introduces missing-wedge artefacts such as elongation and anisotropic resolution, while noisy low-dose data further degrade reconstruction quality and quantitative reliability. Here, we introduce an unsupervised deep learning framework based on Deep Image Prior with total variation regularization (DIP-TV) for limited-angle STEM-EDX tomography. We extend it to a multi-channel formulation (DIPm-TV) that jointly reconstructs multiple elemental maps by exploiting spatial correlations. Using a synthetic 3-channel phantom, we show that the method compensates for severe missing-wedge artefacts corresponding to approximately $100^\circ$ of missing angular range under moderate noise, outperforming simultaneous iterative reconstruction technique and compressed sensing approaches. We apply the method to 3D chemical analysis of Ge-Sb-Te (GST) memory devices in virgin (as-fabricated) and SET (crystalline) operational states. Samples were prepared as cross-sectional focused ion beam lamellae and acquired under a limited-angle tilt range from $-40^\circ$ to $+40^\circ$ with $5^\circ$ steps and a dose of $2.0\times10^5$ $e^-/Ang^2$. The multi-channel approach enables voxel-by-voxel elemental reconstruction using only EDX signals without external structural priors such as high-angle annular dark-field imaging. The reconstructed volumes show near-isotropic spatial resolution and reveal compositional heterogeneities associated with device operation. This approach enables 3D chemical characterization in experimentally accessible sample geometries where conventional methods fail due to severe angular limitations.

When two ferromagnetic thin films with different magnetic easy axes are coupled via the exchange interaction, the magnetization process becomes nontrivial. In this paper, we demonstrate that three-dimensional magnetization information in such a bilayer system can be accessed electrically by combining measurements of the anomalous Hall effect (AHE) and anomalous Nernst effect (ANE). Specifically, we investigate a CoFe$_2$O$_4$(001)/Fe bilayer, where the insulating nature of CoFe$_2$O$_4$ ensures that these transport measurements selectively probe only the conductive Fe layer. By combining the AHE and ANE results and comparing them with a simple micromagnetic simulation, we probe the magnetic configuration of antiferromagnetically coupled Fe layer and suggest the emergence of a twisted magnetic structure near the interface.

We investigate precision scaling at the interface between unitary and non-unitary encoding under generalized noise including single-particle and collective dephasing and decay. Using linear response theory and the error propagation formula, we derive analytic precision expressions for both the unitary parameter $\Omega$ and the dissipation strength $\gamma$. For unitary encoding, when the observable commutes with a Hermitian noise operator, the optimal encoding time is independent of $N$, yielding the Heisenberg limit $\Delta \Omega \propto 1 / N$; otherwise the precision degrades to the standard quantum limit or ceases to improve with $N$. For non-unitary encoding, when $[\hat{A}, \hat{O}] = 0$, the precision is insensitive to intrinsic dynamics and encoding time, scaling as $\Delta \gamma \propto \sqrt{\gamma / \expval*{\hat{L}^\dagger \hat{L}}}$. Notably, for collective decay, the Dicke state reaches the Heisenberg limit $\Delta \gamma \propto 1 / N$, demonstrating that entanglement can enhance non-unitary estimation. Our results provide a unified framework and practical guidance for designing quantum metrology protocols in noisy environments.

This manuscript reports the first direct neutron-scattering evidence for long-period helimagnetism in the newly identified 4d-substituted B20 compound Fe0.5Rh0.5Si. By combining SANS with low-field magnetometry, we establish the magnetic modulation, construct a field-temperature phase diagram, and identify a candidate A-phase region supported by an independent structural signature. The work is important beyond this single compound because it expands the family of chiral B20 helimagnets into Rh-substituted materials, where spin-orbit coupling, disorder, and Dzyaloshinskii-Moriya interactions can be tuned. It will interest researchers in chiral magnetism, topological spin textures, magnetic neutron scattering, and quantum materials, and provides a foundation for future studies of emergent magnetic phases and topology-driven phenomena in chemically tuned chiral magnets.

Across biological scales, from sperm cells to whales, locomotion commonly relies on undulatory gaits, in which traveling deformation waves interact with the surrounding fluid to generate thrust opposite to the direction of wave propagation. In viscous environments, microorganism locomotion is classically understood in terms of undulatory bending of slender filaments such as flagella, with optimal propulsion achieved when the deformation wavelength is comparable to the swimmer length. Inspired by diatom colonies, we identify a fundamentally different swimming mechanism based on sliding between neighboring elements within a chain. We show that sliding between stacked elongated cells generates internal shear that drives propulsion opposite to classical undulatory swimming, while achieving higher speeds and greater energetic efficiency. Remarkably, optimal performance occurs at wavelengths much larger than the chain length and at cell aspect ratios consistent with those observed in natural diatom colonies, suggesting that hydrodynamic efficiency may constitute an evolutionary selective pressure in diatom chains. Together, these results identify sliding as a previously overlooked mode of locomotion in multicellular assemblies and suggest new design principles for efficient bio-inspired microswimmers and swarm robotic systems.

Quantum-entangled states underpin many emergent phenomena in quantum materials, yet their direct experimental identification remains a challenge. NiPS$_3$, a van der Waals antiferromagnet exhibiting a resolution-limited magnetic exciton in its ordered phase, has been proposed to host a many-body entangled Zhang-Rice triplet state. Here, using $^{33}$S nuclear magnetic resonance (NMR) on $^{33}$S-enriched NiPS$_3$ single crystals, we provide microscopic evidence for this charge-transfer state. The $^{33}$S and $^{31}$P Knight shifts as a function of temperature reveal a unified spin-triplet configuration arising from strong hybridization between a self-doped hole in the S $3p$ orbitals and a hole in Ni $3d$ orbitals. Furthermore, the $^{33}$S nuclear spin-lattice relaxation rate exhibits a power-law divergence as it approaches the Néel temperature $T_N=155$ K, indicating critical slowing down of collective charge fluctuations consistent with spin-nematic correlations. These results reveal a spin-charge-intertwined ground state and establish the microscopic foundation for the exceptional coherence of the magnetic exciton in NiPS$_3$.

We elucidate the stress in a system of active Brownian particles augmented with translational and rotational inertia (ABP+TRI). Stress tensors are derived for periodic systems as well as systems confined between walls by employing Lagrange's equations of motion of the first kind for the rotational motion. Using Langevin simulations of an ideal active gas in two dimensions, we confirm the existence of an equation of state for periodic systems that depends on translational and rotational inertia in general. Confinement implies a strong polarization of the propulsion direction near a wall and an enhanced density, both of which increase with increasing rotational inertia. This affects the local stress tensor normal to the confining walls, leading to a breakdown of the equation of state. Yet the local stress in the bulk part of the confined systems is identical with that of the periodic system. Importantly, for both kinds of boundary conditions, the so-called swim stress is not included in the local stress tensor; thus, in general, the swim stress is not representative of the stress in systems of ABP+TRIs.

Moiré superlattices in van der Waals heterostructures have recently gained significant attention as an intriguing platform for studying correlated electronic systems and exotic excitonic properties. Previous reports, however, focused on creating and modulating moiré heterostructures through interlayer twisting or lattice constant mismatches, limiting controls on symmetry of heterostructures. In this work, we show that strain significantly alters the geometry of moiré superlattices by breaking the C3 rotational symmetry. We realize strain-induced moiré superlattices by intentionally regulating interlayer strain in WSe2-MoSe2 heterostructures, which is manifested by linearly polarized interlayer exciton emission coupled to the strain direction. Furthermore, interlayer exciton diffusion was preferentially guided along the stretched moiré superlattice orientations over a wide spatial range, reflecting the strain-modified moiré potentials. Our work highlights strain tuning as a versatile tool for designing moiré superlattices and programming excitonic transport, which opens pathways for van der Waals logic and information processing devices.

We introduce a Langevin formulation of Vicsek-like active particles in which orientations evolve through finite-rate relaxation toward the local mean direction, with alignment strength $J$ and rotational diffusivity $D_r$, thereby combining Vicsek-type local consensus with XY-like orientational dynamics. Using large-scale numerical simulations, we determine the nonequilibrium phase diagram as a function of activity and alignment rate. Increasing the alignment rate drives a sequence of transitions from a homogeneous isotropic state to polar bands, a cross-sea phase of intersecting bands, a homogeneous polar state, and ultimately a micro-clustered regime. The isotropic-to-polar transition is strongly first order, as evidenced by Binder cumulants and bimodal distributions of local polarization and density, indicating coexistence of gas-like and liquid-like regions. Near the onset of collective motion, band size increases with activity but depends non-monotonically on alignment rate. Further increasing the alignment rate drives the system through the cross-sea and homogeneous polar phases before enhanced density fluctuations lead to micro-clustering. Our results demonstrate that finite-time orientational relaxation acts as a control parameter that qualitatively restructures collective behavior in polar active matter.

We show that the transconductance of multilayer WSe$_2$ field-effect transistors serves as a direct electrical spectrometer of the intervalley relaxation time $\tau_{\rm iv}$, previously accessible only by ultrafast optical techniques. Extending an equilibrium valley-thermodynamics framework with a single relaxation equation for the $\Gamma$-valley carrier fraction $f_\Gamma(t)$, we predict three signatures: (i)~a Lorentzian transconductance $g_m(\omega)=g_{m,0}+g_{m,v}^0/(1+i\omega\tau_{\rm iv})$, whose imaginary part peaks at $\omega_c=\tau_{\rm iv}^{-1}$ with opposite signs for bilayer and trilayer; (ii)~a two-stage current transient after a gate step, exhibiting bilayer overshoot or trilayer undershoot; and (iii)~sweep-rate-proportional hysteresis whose gate-voltage profile and the layer-dependent transconductance sign reversal distinguish valley from trap-induced dynamics. All three signatures provide quantitative electrical access to $\tau_{\rm iv}$ with standard radio-frequency (rf) and direct-current (dc) instrumentation.

Active microcarriers capable of transporting multiple functional components and navigating complex environments are highly desirable for biomedical applications, yet their fabrication typically requires complex multistep processes. Here we show that evaporation-induced liquid-liquid phase separation in all aqueous polymer and protein mixtures provides a simple one-step route to multifunctional micromotors. During droplet evaporation, micron-sized condensates spontaneously form and encapsulate enzymes, nanoparticles, and drugs. Evaporation-induced Marangoni flows and interfacial adsorption generate asymmetric internal self-organization of nanoparticles, producing Janus-like architectures and spontaneously emergent shape anisotropy without the need for patterned fabrication. Dual functionality with internal magnetic anisotropy allowed catalytic propulsion steered by magnetic torque, enabling directional motion even in homogeneous environments. Thus, we present a versatile platform for the one-step construction of biocompatible, multifunctional micromotors with internally asymmetric architectures.

Classical nucleation theory describes the rate at which stable nuclei form within a metastable parent phase by crossing a free-energy barrier set by competing bulk and interfacial energies. In an elastic material, a pre-existing stress state modifies this barrier through an elastic contribution to the bulk driving force. This contribution is well characterized for linear elastic materials, but the corresponding finite-deformation result for soft solids remains less developed. The gap is computationally significant: in simulations that sample candidate nuclei throughout a stressed body, direct evaluation of the elastic contribution to free-energy change would require solving a new nonlinear elasticity boundary-value problem for each possible nucleus. Here, we derive an asymptotic expansion of the equilibrium elastic potential energy change for a hyperelastic body before and after formation of a small transformed region. The expansion is with respect to the amplitude of an isotropic transformation strain, while the pre-existing deformation and stress may be finite. At leading order, the elastic contribution to the formation energy is determined entirely by the known untransformed equilibrium fields, with additional terms accounting for stiffness contrast between the parent and transformed phases. Incorporating this into classical nucleation theory yields the stress-shifted transformation temperature, critical radius, and nucleation barrier. Representative results are shown for a compressible neo-Hookean solid under hydrostatic, uniaxial, and equibiaxial loading; tensile stresses promote nucleation and compressive stresses suppress it when transformation strain is expansive. Comparison with the corresponding linear-elastic result shows that finite-deformation effects can substantially change the predicted energy barrier at moderate stretches.

Confined active systems can sustain persistent vortical flows whose stability is strongly influenced by boundary conditions. At the individual level, active units generate internal stresses that drive spontaneous flows, which in turn advect and reorient the particles. This nonlinear coupling between active flow and orientational order is significantly mediated by the system's boundaries, where the specific slip condition governs how these internal stresses generate active flow then rearrange the local orientations. However, a quantitative understanding of how boundary slip dictates their dynamical stability remains lacking. Here, we study how the slip boundary condition controls the stability of a steady vortex state in a circularly confined active nematic system. Using a continuum model in a flow-dominated regime, we perform a linear stability analysis and derive an explicit criterion incorporating the slip velocity and flow-alignment coupling. We find that increasing slip velocity suppresses localized linear instabilities, thereby promoting the persistence of the steady vortex state. This reveals a relaxing the boundary friction actually stabilizes the macroscopic coherent structure by depressing flow induced reorientation that typically destroys single-vortex states. Our findings establish boundary slip as a nontrivial hydrodynamic control parameter for engineering stable active flows.