We show that relaxation of the charge-imbalance potential plays a key role in the retarded dynamics of Abrikosov vortices in a type-II superconducting sample carrying a microwave current. Starting from the time-dependent Ginzburg-Landau equations we derive the vortex equation of motion accounting for both the dissipation and retardation effects. The retardation is governed by the dynamics of the charge-imbalance potential and reveals itself at characteristic timescales diverging near the superconducting critical temperature $T_c$. These retardation effects in vortex dynamics strongly affect the kinetic inductance of superconducting circuits being, thus, responsible for the magnetic field dependence of characteristics of different superconducting devices in the high-frequency range.

Metal hydrides are typically nonstoichiometric compounds at ambient pressure, commonly exhibiting hydrogen vacancies. Recently, hydrogen-rich metal hydrides featuring clathrate hydrogen sublattices have attracted great attention as potential room-temperature superconductors under pressure. However, accurately determining their hydrogen stoichiometry remains experimentally challenging, and the impact of hydrogen vacancies on their superconductivity is unclear. Here, we investigate the superconductivity and thermodynamic properties of ${\mathrm{CeH}}_{10}$ with hydrogen vacancies. Our results reveal that the nonstoichiometric clathrate hydride ${\mathrm{CeH}}_{9.75}$, featuring hydrogen vacancies in a fcc lattice, exhibits lower thermodynamic stabilization pressure compared to the perfect ${\mathrm{CeH}}_{10}$ crystal. While hydrogen vacancies are generally known to induce superionic states in clathrate hydrides, we find that the superionic transition temperature for ${\mathrm{CeH}}_{9.75}$ is actually higher than that of ${\mathrm{CeH}}_{10}$, suggesting that hydrogen vacancies may increase the hydrogen diffusion barrier and enhance the stability of clathrate hydrides under pressure. Furthermore, the calculated superconducting transition temperature of ${\mathrm{CeH}}_{9.75}$ show excellent agreement with experimental data. These findings indicate that nonstoichiometry may be a common feature in the high-pressure phase diagrams of clathrate hydrides.

Quantum tunneling suppresses extreme nanofocusing in plasmonic cavities while significantly enhancing the electric field gradient. This study employs a plasmonic cavity to drive multipolar Raman scattering of asymmetric thiobenzonitrile, directly observing this phenomenon via the quadrupole-to-dipole Raman intensity ratio. The quantum-corrected model shows that at the subnanometer gap, quantum tunneling simultaneously quenches the electric field enhancement (manifested as a decrease in dipole Raman intensity) and amplifies the electric field gradient effect (resulting in a continuous rise in quadrupole Raman intensity). Experimentally, the introduction of thiobenzonitrile molecules lowers the potential barrier height, enabling quantum tunneling to occur at a larger gap size. This leads to the quadrupole Raman intensity surpassing the dipole Raman intensity (with an enhancement exceeding three orders of magnitude). This work provides new strategies for molecular detection and spectroscopic selection rule manipulation in surface/tip-enhanced Raman spectroscopy and opens avenues for exploring quantum interactions within plasmonic cavities.

The electronic band structure of ${\mathrm{CaSnN}}_2$ in the wurtzite-based $Pna{2}_1$ structure is calculated using the quasiparticle self-consistent$G{W}^{\mathrm{BSE}}$ method, including ladder diagrams in the screened Coulomb interaction $W^{\mathrm{BSE}}$ and is found to have a direct gap of 2.59 eV at $\mathrm{\Gamma }$, which corresponds to blue light wavelength of 478 nm and makes it an attractive candidate for sustainable blue light-emitting diodes, avoiding Ga and In. The valence band splitting is analyzed in terms of symmetry labeling and the effective mass tensor is calculated for several bands at $\mathrm{\Gamma }$. The valence band maximum has $a_1$ symmetry and gives allowed transitions to the conduction band minimum (also of $a_1$ symmetry) for light polarized along the c direction. While this is unfavorable for light emission with transverse electric or $s$ polarization from the basal plane, this would not be an impediment if another surface than the basal plane is used. Furthermore, the crystal field splitting between the $a_1$ and $b_1$ states, corresponding to polarizations along c and a respectively, reverses under an applied uniaxial tensile strain of 3.7% along the c direction, which might occur under biaxial compressive strain in the basal plane. The optical dielectric function including electron-hole interaction effects is also reported and the excitons are analyzed, including several dark excitons.

${\mathrm{Fe}}_3{\mathrm{GeTe}}_2$ is a paradigmatic van der Waals magnet with the full microscopic picture of magnetic interactions still under debate. Here, we use scanning tunneling microscopy and spectroscopy at 1.1 K to map out the low-energy physics on the surface. In agreement with previous works, we observe a spatially varying Fano line shape that has been ascribed to a Kondo resonance. In addition, we identify a small gap of $\approx 2.3\mathrm{meV}$ width on top of the larger-energy Fano resonance. We suggest that this gap is the signature of a coherent Kondo lattice that has been proposed to originate from hybridization of a strongly dispersing and a flat band both derived from $d$ electrons of the Fe atoms in the lattice. Adding magnetic adatoms on the surface hardly influences the magnetic signatures of the substrate, indicating the robustness of the intralayer Kondo correlations against magnetic adsorbates.

Recently discovered high-$T_c$ superconductivity in thin-film bilayer nickelates ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ under ambient pressure has attracted great interest. Non-Fermi-liquid transport behaviors, such as $T$-linear resistivity and a positive Hall coefficient that increases at low temperatures, have been reported in this system. In this study, we analyze the non-Fermi-liquid transport phenomena in the thin-film bilayer nickelate ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ using a multiorbital tight-binding model. In ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$, the cold spots composed of the Ni $d_{x^2-y^2}$ orbital emerge, since the spin fluctuations cause stronger quasiparticle damping $\gamma$ in the Ni $d_{z^2}$ orbital. Notably, in the present study, we derive a rigorous formula for the Hall coefficient $R_H$ incorporating the $\gamma$ in the quasi–quantum metric (qQM) term. We find that the $T$ dependence of $\gamma$ in the qQM term is important in determining $R_H$. In ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$, the $T$ dependence of $R_H$ becomes pronounced due to the competition between the positive contribution from the hole band and the negative contribution from the electron band. Moreover, the qQM term plays an important role in describing the Nernst coefficient and other transport phenomena involving the second derivative velocity $v^{\mu \nu }$.

We study theoretically the role of electron-electron interactions in one-dimensional magnetized helical states coupled to an $s$-wave superconductor. We consider a partially mixed helical (superhelical) regime, where the magnetic field (superconductivity) has a dominant contribution. Using bosonization and renormalization-group techniques, it is shown how the interactions affect the correlation functions in the system. In the partially mixed helical regime, we find that superconducting pairing promotes spin-density-wave correlations, while singlet and triplet pairing correlations are suppressed, especially under attractive interactions. In contrast, in the superhelical regime, a perturbative Zeeman field enhances both spin singlet and spin triplet-$x$ pairings under repulsive interactions. We calculate both logarithmic and residual corrections to charge-density-wave, spin-density-wave, and pairing correlations, revealing short- and long-range behaviors. We further investigate spin transport properties supplemented by a renormalization-group analysis of the temperature and frequency dependence of spin conductivity. We also analyze the transport of momentum-spin-locked carriers in the presence of Zeeman-induced and pairing-induced gaps, uncovering the effect of interactions and the interplay between the two gaps in helical systems.

Quasi-one-dimensional transition-metal chalcogenide ${\mathrm{Ta}}_2{\mathrm{PdSe}}_6$ is a promising thermoelectric semimetal due to the strong electron-hole asymmetry in the carrier lifetime. However, the microscopic origin of such a strong asymmetry remains unclear. In this study, we theoretically investigate electron-phonon scattering in ${\mathrm{Ta}}_2{\mathrm{PdSe}}_6$. There is a soft phonon mode mainly consisting of atomic displacements in ${\mathrm{PdSe}}_4$ chains. This soft mode is strongly coupled with the highest valence band at the $\mathrm{\Gamma }$ point, which lies slightly below the Fermi energy, and causes strong electron-phonon scattering. The bottom of the electron pocket energetically overlapped with that band also suffers from strong intervalley scattering, by which the imaginary part of the electron self-energy exhibits a sharp change near the Fermi level. On the other hand, the imaginary part of the self-energy for carriers in the hole pocket shows a moderate energy dependence. Thus, we find that electron-phonon scattering is strongly valley-dependent. Our finding will help us to understand the distinctive transport properties observed in ${\mathrm{Ta}}_2{\mathrm{PdSe}}_6$.

Recent experiments on donor-based spin qubits in silicon have leveraged the exchange interaction between electrons bound to separate donor nuclei to perform two-qubit operations. A consistently observed yet unexplained phenomenon in such systems is the significant increase in electron readout contrast, measured via Elzerman-style readout to a single-electron transistor (SET) island, when the donor nuclei are initialized in a parallel spin orientation compared to an antiparallel orientation. In this work, we present a detailed analysis of the exchange-coupled donor system in the parallel nuclear regime and propose a physical mechanism for this effect. We attribute the enhanced readout contrast to an additional electron tunneling event to the SET during a single read period, when the donor nuclei are aligned in a parallel spin configuration. These insights inform strategies for improving electron readout fidelity in these systems and contribute to a more complete understanding of spin-dependent tunneling processes in donor-based qubit architectures.

Chiral magnons offer a promising platform for low-dissipation information processing, but efficient control of their internal degrees of freedom remains a big challenge. Here we demonstrate that dipolar interactions provide an intrinsic mechanism for coherent control of magnon chirality in antiferromagnets. Using an effective two-band model, we show that dynamical dipolar fields induce coherent hybridization between opposite-chirality antiferromagnetic magnon modes, giving rise to Rabi oscillations. The oscillation frequency is highly sensitive to material parameters and geometry, enabling multiple routes for tunable control. By engineering magnetic heterostructures, we further demonstrate chirality-selective magnon confinement in Fabry-Pérot–type resonators and the formation of one-dimensional magnonic crystals. Our findings are validated by atomistic spin-dynamics simulations and micromagnetic simulations, establishing dipolar-induced chiral hybridization as a viable mechanism for controlling antiferromagnetic spin waves. These results open new avenues for chirality-based magnonic devices and antiferromagnetic information processing.

Extreme-value fluctuations at quantum critical points remain poorly understood in the presence of strong correlations and open-system amplification. We study the maximum wave-function amplitude in the open Chalker-Coddington network at the integer quantum Hall transition. Because the stationary scattering state is not normalized to unit total intensity, its largest amplitude contains both a sample-dependent global intensity scale and an intrinsic spatial extreme. We separate these contributions by writing the state as a total gain times a normalized spatial pattern. The raw maximum shows near-log-normal statistics over the studied sizes and an approximately parabolic extreme-moment exponent in a moderate moment window. We show that this behavior is strongly shaped by the fluctuating gain. After gain normalization, the maximum has a qualitatively different exponent function and does not collapse to a standard generalized extreme-value form under the same centering and scaling. These results identify extreme amplitudes as sensitive probes of open quantum criticality and separate collective amplification from intrinsic rare-event fluctuations.

When a local impurity spin interacts with conduction electrons whose density of states (DOS) has a (pseudo)gap or diverges at the Fermi energy, a local moment (LM) phase can be favored over a Kondo phase. Theoretically studying quantum entanglement between the impurity and conduction electrons, we demonstrate that conduction electrons form an LM spin cloud in general LM phases, which corresponds to, but has a fundamental difference from, the Kondo cloud screening the impurity spin in the Kondo phase. The LM cloud algebraically decays over the distance from the impurity when the DOS has a pseudogap or divergence, and exponentially when it has a hard gap. We find an LM cloud length, a single length scale characterizing a universal form of the LM cloud. The findings are supported by both analytic theories and numerical computations.

The long-standing question of whether the residual entropy of hexagonal ice ($S_h$) equals that of cubic ice ($S_c$) remains unresolved despite decades of research on ice-type models. While analytical studies have established the inequality $S_h\ge S_c$, numerical investigations suggest that the two values are very close. In this work, we revisit this problem using high-precision tensor network methods. In the Monte Carlo approaches used most commonly, the residual entropy cannot be directly obtained by sampling the ground-state degeneracy space. However, the tensor network framework enables an explicit encoding of the “ice rule” into local tensors, and then the residual entropy is transformed into finding the largest eigenvalue of a transfer operator in the form of a projected entangled-pair operator, which allows high-accuracy numerical evaluation. Meanwhile, we propose a perspective based on analyzing the normality of the transfer operator and examine it numerically with variational tensor network methods. This analysis allows for a direct computation for both residual entropies with our recently developed split corner transfer matrix renormalization group algorithm, providing a numerical evidence supporting the equality between $S_h$ and $S_c$.

Magnetic skyrmions driven by spin-orbit torque (SOT) are promising for energy-efficient spintronics. However, their description relies on dynamical models treating dissipation phenomenologically, leaving the fundamental dynamics-dissipation link unresolved. Here, we establish a thermodynamic framework bridging atomic spin dynamics with macroscopic thermodynamics. By decomposing SOT into conservative and nonconservative components, we complete the energy pathway from microscopic current injection to macroscopic heat, thereby transforming the observed velocity-dissipation decoupling from a phenomenological rule into a design principle governed by material parameters ($\beta {\gamma }_S$). As an energy-accounting framework for driven magnetic textures, it provides a quantitative route to connect transport with dissipation and heating, and it may be adapted to other driven ferroic textures when a Langevin-type description is applicable.

Here, we report the structure-property relationship in pressurized $4\mathit{Ha}-{\mathrm{TaSe}}_2$ single crystals. Electrical transport and low-temperature Raman spectroscopy measurements indicate a charge density wave (CDW) transition at $T_{\mathrm{CDW}}\sim 120$ K under ambient pressure. High-pressure transport experiments reveal a competitive relationship between superconductivity (SC) and CDW in $4\mathit{Ha}-{\mathrm{TaSe}}_2$. Under compression, the CDW order is progressively suppressed and vanishes abruptly at a critical pressure $P_{\mathrm{c}}$ of ∼19 GPa. In contrast, the superconducting transition temperature is gradually enhanced from $T_{\mathrm{c}}\sim 3.1$ K at ambient pressure to an optimal $T_{\mathrm{c}}\sim 7.8$ K at $P_{\mathrm{c}}$, followed by a slow reduction up to 83.7 GPa. Synchrotron x-ray diffraction experiments show that the pristine hexagonal structure remains stable under pressure, while the dimensionality transforms from quasi-2D to quasi-3D near $P_{\mathrm{c}}$. Simultaneously, Raman vibrational modes exhibit significant anomalies around $P_{\mathrm{c}}$, including changes in Raman intensity and pressure coefficients of normal in-plane modes, as well as in a two-phonon mode. Thus, the collapse of the CDW near $P_{\mathrm{c}}$ and the domelike superconducting phase diagram could be related to a dimensional crossover in the crystal structure. These findings not only establish the pressure-temperature phase diagram of $4\mathit{Ha}-{\mathrm{TaSe}}_2$ polytype but also facilitate the systematic understanding of the interplay between SC and CDW across the transition-metal dichalcogenides family of materials.

We perform first-principles electron-phonon calculations to evaluate the superconducting transition temperature $T_c$ for ternary superhard metals ${\mathrm{B}}_2{\mathrm{C}}_3\mathrm{N}$ and ${\mathrm{B}}_4{\mathrm{C}}_5{\mathrm{N}}_3$. An ambient-pressure $T_c$ of $\sim 40\mathrm{K}$ and $\sim 20\mathrm{K}$ is obtained respectively for ${\mathrm{B}}_2{\mathrm{C}}_3\mathrm{N}$ and ${\mathrm{B}}_4{\mathrm{C}}_5{\mathrm{N}}_3$ from the Eliashberg gap equations. The relatively high $T_c$ of these compounds is due in part to their high Debye temperatures associated with superhardness. The materials under study are potentially synthesizable, as their formation energies are comparable to those of other recently synthesized superhard B-C-N compounds. Therefore, studying superhard metals could hold the promise of realizing new higher-$T_c$ superconductors at ambient pressure.

The interplay of topology, disorder, and non-Hermiticity gives rise to phenomena beyond the conventional classification of quantum phases. We propose a one-dimensional non-Hermitian Su-Schrieffer-Heeger model with quasiperiodically modulated nonreciprocal intracell hopping. We show that quasiperiodic modulation can substantially enhance the topological regime and, remarkably, induce a non-Hermitian topological Anderson insulator (TAI) phase. Beyond the topological transition, increasing nonreciprocity drives a cascade of localization transitions in which all bulk eigenstates evolve from extended to multifractal critical and ultimately to localized states. Strikingly, the extended-to-critical transition coincides exactly with a real-complex spectral transition. We establish complete phase diagrams and derive exact analytical boundaries for both topological and localization transitions, uncovering an unanticipated coexistence of TAI and multifractal critical phases. Finally, we propose a feasible implementation in topolectrical circuits. Our results reveal a new paradigm for studying the cooperative effects of topology, quasiperiodicity, and non-Hermiticity.