Superconductivity of a single two-dimensional Dirac fermion offers a natural route to topological superconductivity. While usually considered extrinsic—arising from proximity to a conventional superconductor—we investigate when a doped Dirac cone can spontaneously develop superconductivity from a short-range repulsive interaction $U$ via the Kohn–Luttinger mechanism. We show that an ideal, linear Dirac cone is immune to pairing at leading order in $U^2$. Superconductivity instead emerges only through higher-order in $k$ corrections to the dispersion, which are unavoidable in any lattice realization and crucially dictate the pairing symmetry. The form of the pairing thus reflects how the well-known obstruction to realizing a single Dirac cone on a lattice is circumvented. When a Dirac cone arises from broken time-reversal symmetry—for instance, at a transition between Chern insulators or in a valley-polarized phase—we find a topological $p-ip$ state whose chirality is opposite to that of the parent chiral metal above $T_c$. By contrast, for a surface Dirac cone of a 3D topological insulator, superconductivity is stabilized by anisotropies in the dispersion. For $C_{3v}$-symmetric warping, as in ${\mathrm{Bi}}_2{\mathrm{Te}}_3$, pairing is strongest when the Fermi surface becomes hexagonal, leading to order in the $(d\pm id)\times (p+ip)$ channel with accidental near-nodes. In the highly anisotropic limit $v_x\gg v_y$, relevant to side surfaces of layered materials, the Fermi surface splits into two branches, and nesting favors a pairing symmetry $\mathrm{\Delta }\sim \mathrm{sgn}\left(k_x\right)cos\left(k_y\right)$ reminiscent of organic superconductors.

Two-dimensional ferroelectrics hold great promise for ultrathin, energy-efficient electronic and memory devices. Unlike homobilayers, where the number of candidate bilayers scales linearly with the number of monolayers, the vast design space of heterobilayers, combined with their intrinsically sparse ferroelectric occurrence, renders brute-force screening highly inefficient. Here, we address this challenge by identifying key physical descriptors through high-throughput first-principles calculations on 33 102 hexagonal stacking configurations and by developing a monolayer-informed predictive model that enables rapid identification of sliding ferroelectricity in heterobilayers without explicitly constructing bilayer structures. Relying on monolayer-level descriptors, the model achieves high-fidelity predictions across a broad materials space. Applying this framework, we uncover more than 1000 sliding ferroelectric heterobilayers with out-of-plane polarization (OOP) exceeding that of experimentally reported ${\mathrm{MoS}}_2/{\mathrm{WS}}_2$. Notably, the top-performing candidate exhibits an OOP response approximately 130 times larger than ${\mathrm{MoS}}_2/{\mathrm{WS}}_2$. These results establish a large curated dataset of sliding ferroelectrics and demonstrate a scalable, structure-free discovery paradigm for ferroelectric heterobilayers, paving the way for accelerated design of next-generation two-dimensional ferroelectric devices.

The phonon pumping effect has been studied theoretically and the frequency-dependent contribution to the magnetic damping is predicted. Here, we experimentally investigate the magnetic damping arising from phonon pumping in the ${\mathrm{LiNbO}}_3/{\mathrm{Y}}_3{\mathrm{Fe}}_5{\mathrm{O}}_{12}$ heterostructures. The broadband ferromagnetic resonance and microwave absorption spectroscopy are employed to characterize the magnetization dynamics and magnetic damping. The magnetic damping exhibits nonlinear frequency dependence and thickness correlation. The microwave absorption spectroscopy results reveal a discrete signal profile, distinct from conventional continuous signals, which is correlated with the elastic waves propagating along in-plane directions.

Using an asymmetric two-leg ladder comprising pairing and metallic chains, this Letter proves the striking power of reservoir-mediated boosting of superconductivity. Using many-body numerics on large systems at zero and finite temperature, we unravel the processes by which the metal parameters can impact the effective pairing strength and the ranged pair-pair coupling mediated by the metal. These then enhance key superconducting properties far above those of the isolated system. Thus, our Letter identifies a general mechanism by which reservoirs can strongly suppress the effects of the Mermin-Wagner theorem in finite-sized systems, allowing even large one-dimensional systems to appear practically ordered.

Superlattice engineering has proven to be a practical approach for modulating the functional properties of oxide perovskites in both theoretical and experimental research. Recently, some nitride perovskites have been successfully synthesized; however, several of them display metallic behavior, highlighting the need for reliable strategies to achieve a ferroelectric insulating phase. In this work, we designed a series of nitride perovskite superlattices with the general formula $(\mathrm{A}/{\mathrm{A}}^{\prime }){\mathrm{B}}_2{\mathrm{N}}_6$ ($\mathrm{A}=\mathrm{Nb}$, W, Mo, etc.; ${\mathrm{A}}^{\prime }=\mathrm{Ga}$, Hf, Ta, etc.; $\mathrm{B}=\mathrm{Ta}$, Zr, V, etc.) using first-principles calculations and identified 19 candidates with $E_{\mathrm{hull}}<200\mathrm{meV}/\mathrm{atom}$, band gaps of 1.01 to 2.19 eV, and polarizations up to $103.73\mu \mathrm{C}/\mathrm{c}{\mathrm{m}}^2$ in $\left(\mathrm{Nb}/\mathrm{Ga}\right){\mathrm{Ta}}_2{\mathrm{N}}_6$. Further analysis reveals that the ferroelectricity is driven by trilinear coupling of ${\mathrm{\Gamma }}_5^{-}$ polar, ${\mathrm{M}}_3^{+}$ rotation, and ${\mathrm{M}}_5^{-}$ tilt modes. In addition, our study shows that the A-site cation radius and the Jahn-Teller effect of the B-site cation significantly influence polarization strength in the $(\mathrm{A}/{\mathrm{A}}^{\prime }){\mathrm{B}}_2{\mathrm{N}}_6$ system. This work expands the family of nitride perovskite ferroelectrics and provides theoretical guidance for future experimental synthesis of nitride perovskite ferroelectric superlattices.

Development of spintronic and quantum computing devices increases demand for efficient, energy saving method of spin manipulation at molecular scale. Polyoxovanadate molecular magnets being susceptible to both electric and magnetic fields may serve here as a good base material. In this paper, two isostructural anions $[{\mathrm{V}}_{12}{\mathrm{As}}_8{\mathrm{O}}_{40}$(${\mathrm{HCO}}_2{\left)\right]}^{n-}$ (with $n=3,5$) featuring two different mixed-valence states with itinerant and localized valence electrons are studied. The impact of the electric field on their magnetic properties is investigated by means of two complementary methods informed by magnetic measurements: effective Hamiltonian calculations and density functional theory. It is demonstrated that the magnetoelectric effect in theses molecules is induced mostly by relocation of itinerant electrons, is highly anisotropic, depends on the valence state and can be detected even at room temperature. These findings can pave the way to practical applications in which an electric field control over spin state is required.

The morphotropic phase boundary (MPB) is the cornerstone of designing high-performance piezoelectric ceramics, enabling materials such as $\mathrm{Pb}\left(\mathrm{Zr},\mathrm{Ti}\right){\mathrm{O}}_3, \mathrm{Pb}\left(\mathrm{Mg},\mathrm{Nb}\right){\mathrm{O}}_3–\mathrm{PbTi}{\mathrm{O}}_3, \left(\mathrm{K},\mathrm{Na}\right)\mathrm{Nb}{\mathrm{O}}_3$-based and $\mathrm{BaTi}{\mathrm{O}}_3$-based (BT) ceramics to have excellent piezoelectric coefficients (exceeding 600 pC/N). In contrast, MPB in $\left(\mathrm{Bi},\mathrm{Na}\right)\mathrm{Ti}{\mathrm{O}}_3$-based (BNT) materials exhibits a notable anomaly: despite their high spontaneous polarization, their piezoelectric coefficients are limited to ∼300 pC/N. This work systematically compares the properties and in situ microstructures of MPB in BT-based (no oxygen octahedral tilting) and BNT-based (with oxygen octahedral tilting) systems, and reveals that oxygen octahedral tilting leads to a unique MPB type in the BNT-based system. In BT-based systems, the MPB composition (no oxygen octahedral tilting) maintains a two-phase coexistence structure before and after the application of an electric field and exhibits a low polarization rotation energy barrier, thereby generating a high piezoelectric coefficient. In contrast, in BNT-based systems, when an electric field is applied, the MPB composition (with oxygen octahedral tilting) undergoes a field-induced transition, transforming from a two-phase coexistence structure to a single-phase structure. This single-phase structure and oxygen octahedral tilting result in a high energy barrier for polarization rotation, leading to a low piezoelectric coefficient and a high coercive field. These results provide insights into the microstructural origin of the abnormal properties of BNT-based MPB piezoelectrics and the design of high-performance lead-free materials.

We have studied ferromagnetic resonance in amorphous trilayers of ${\mathrm{Co}}_x$(${\mathrm{Al}}_{0.70}{\mathrm{Zr}}_{0.30}{)}_{1-x}$. The trilayer composition is such that the outer layers are ferromagnetic, with distinct resonance frequencies, while the spacer layer composition is nominally paramagnetic. We observe two precessional modes, acoustic and optical, and follow these as the interlayer exchange coupling, mediated by a strong proximity-induced magnetization in the spacer, is varied by changing the spacer layer thickness. We find that both the interlayer exchange coupling and the induced magnetization have an exponential decay profile within the spacer, with contrasting decay lengths of ${\lambda }_{\mathrm{IEC}}$ = 0.44 nm and ${\lambda }_{\mathrm{PIM}}$ = 3.1 nm. This contrast exposes the difference in decay length of spin stiffness, reflected in resonance experiments, and proximity-induced magnetization or polarizability in these amorphous trilayers, from static magnetization measurements.

In this work, we investigate the impact of Rashba spin-orbit coupling (RSOC) on the formation of charge-density-wave (CDW) and superconducting (SC) phases in the Holstein model on a half-filled square lattice. Using unbiased finite-temperature quantum Monte Carlo simulations, we go beyond mean-field approaches to determine the ground-state order parameter as a function of RSOC and phonon frequency. Our results reveal that the Rashba metal is unstable due to particle-hole instabilities, favoring the emergence of a CDW phase for any RSOC value. In the limit of pure Rashba hopping, the model exhibits a distinct behavior with the appearance of four Weyl cones at half-filling, where quantum phase transitions are expected to occur at strong interactions. Indeed, a quantum phase transition, belonging to the Gross-Neveu Ising universality class between a semimetal and CDW, emerges at finite phonon frequency-dependent coupling ${\lambda }_c$. In the antiadiabatic limit, we observe an enhanced symmetry in the infrared that unifies SC and CDW orders. These results advance our understanding of competing CDW and SC phases in systems with spin-orbit coupling, providing insights that may help clarify the behavior of related materials.

Recent experiments have observed superconductivity proximate to the $\nu =-2/3$ fractional quantum anomalous Hall (FQAH) insulator in twisted ${\mathrm{MoTe}}_2$. A critical open question is whether the underlying normal state is a Fermi liquid with a large Fermi surface or a strongly correlated metal with low carrier density. In this work, we develop a theory of the phases emerging from doping the $\nu =-2/3$ fractional Chern insulator (FCI). We establish a duality between this problem and doping a gapped ${\mathrm{SU}\left(3\right)}_1$ chiral spin liquid (CSL). In both scenarios, one possible metallic state upon doping is a holon metal featuring three small Fermi pockets. These pockets are formed by spinless charge $-e$ holons in the CSL case and charge $-e/3$ fractionalized holes in the FCI case. While the holon metal is susceptible to pairing instabilities driven by gauge fluctuations—leading to a charge density wave (CDW) metal—it may be stabilized by a magnetic field, where it would exhibit an anomalous quantum oscillation period. We identify two distinct chiral superconducting phases that can emerge either from the CDW metal or directly from the holon metal. Finally, we argue that superconductivity arising directly from an anyon gas is not likely if the lowest-energy anyon carries the elementary charge $e/3$.

Multipolar interactions play a pivotal role in governing emergent phenomena in quantum materials, including multiferroics and quantum magnetism. In this work, we determine the ground-state phase diagram of the nearest-neighbor spin-$\frac{3}{2}$ bilinear-biquadratic-bicubic Heisenberg model on the square lattice through a combination of mean-field theory and exact diagonalization. We demonstrate that quantum fluctuations can drive the emergence of multisublattice ordered phases, even on a bipartite lattice, provided that multipolar interactions are sufficiently strong. To characterize the excitation spectra across these distinct phases, we develop cluster spin-wave theory—an extension of conventional linear spin-wave theory—which enables the reliable description of both low-energy magnon dispersions and high-energy multimagnon continua. Our findings offer valuable insights into the nature of collective excitations in strongly correlated spin systems and establish a robust theoretical framework for understanding spin dynamics in complex quantum magnets.

We study spin polarization induced by locally injected electric currents in a metal whose spin-orbit coupling reflects its structural chirality. We reveal both spin polarization in the bulk in the linear response and antiparallel spin polarization near the interface in the quadratic response to external electric currents and reproduce the experimentally observed correlation between the chirality of the metal and the direction of spin polarization. In particular, we elucidate that the sign of the spin polarization in the quadratic response is opposite to that expected from the bulk spin current. This sign discrepancy originates from spin polarization induced by dipole-like charge distribution appearing in the quadratic response.

We perform a comprehensive study on the correlated electronic structure reconstruction of paramagnetic ${\mathrm{VI}}_3$ crystal in its rhombohedral and monoclinic structural phases. Using density-functional plus dynamical mean-field theory ($\mathrm{DFT}+\mathrm{DMFT}$) calculations, we explicitly demonstrate the importance of local dynamical correlations for a consistent understanding of the emergent Mott state, showing the interplay between orbital-dependent one-electron line shape and multiorbital electronic interactions. Our results for the Mott gap are shown to be consistent with extant theory and experimental studies on nonmagnetic ${\mathrm{VI}}_3$ bulk crystal. We also explore the changes in the strongly correlated electronic state upon increasing the total $V$ band filling of monoclinic ${\mathrm{VI}}_3$, showing the robustness of Mott localization against electron doping. Our correlated many-body study is relevant to understanding the electronic structure reconstruction of paramagnetic vanadium-contained trihalide crystals and should be widely applicable to other van der Waals magnetic materials.

For the transparent transition-metal oxide ${\mathrm{LiTi}}_2{\mathrm{O}}_4$(LTO), optical and electronic spectra were investigated using a nonempirical computational approach, the quasiparticle self-consistent GW method (QSGW). The converged one-particle Hamiltonian determined the band dispersion curves, which exhibited a narrower bandwidth and an increased density of states at the Fermi level due to electron localization effects, compared to results obtained with density functional theory. The dielectric function obtained via QSGW revealed that pseudoplasmons arising from interband optical transitions appear in the infrared frequency range, providing a full explanation for the transparency of LTO. By evaluating the self-energy of the hole quasiparticles, the properties of plasmonic polarons were investigated across the Brillouin zone using the cumulant approach under the QSGW framework. Their energy spectra, including plasmon satellites, were discussed in comparison with available experimental photoemission spectroscopy data.

We investigate the tunneling magnetoresistance (TMR) of a bilayer system made of $X$-wave magnets with $X=p,d,f,g,i$, where $X=d,g,i$ corresponds to altermagnets. A universal analytic formula is derived for the TMR ratio. It is proportional to $\left|J\right|/\left(N_X\mathrm{\Gamma }\right)$ for small $\mathrm{\Gamma }$, where $N_X$ is the number of the nodes of the $X$-wave magnet, $J$ is the strength of the $X$-wave magnet, and $\mathrm{\Gamma }$ is the self-energy. It is contrasted with the TMR ratio made of ferromagnets, where it is proportional to $J^2/{\mathrm{\Gamma }}^2$ for small $\mathrm{\Gamma }$. Therefore, the TMR ratio is larger in ferromagnets for $\left|J\right|>\mathrm{\Gamma }$. However, the $X$-wave magnets are expected to achieve high-speed and ultradense memory owing to the zero net magnetization.

We propose and characterize a different class of Majorana boundary states, i.e., floating Majorana edge bands (FMEBs), which emerge in two-dimensional superconductors that break time-reversal symmetry yet host helical-like transport. In contrast to conventional chiral or helical edge modes, FMEBs form isolated, momentum-separated counterpropagating Majorana modes detached from the bulk continuum. We identify a minimal mechanism for their emergence via anisotropic Wilson masses in a two-band Bogoliubov–de Gennes model, and demonstrate their microscopic realization in a quantum anomalous Hall (QAH) insulator proximitized by a $d$-wave superconductor. Using nonequilibrium Green's function simulations, we uncover clear transport fingerprints: a quantized total thermal conductance in two-terminal devices, and a robust half-quantized plateau in four-terminal geometries that cleanly distinguishes FMEBs from chiral $\mathcal{N}=\pm 2$ QAH phases. This thermal response remains remarkably stable under finite temperature, moderate long-range disorder, and finite chemical potential. Our findings establish FMEBs as an experimentally accessible route toward helical-like Majorana transport in systems without time-reversal symmetry, with direct implications for topological quantum computation.