Topological point states (TPSs) have the same physical mechanism as that of the topological corner states (TCSs) in higher-order topological insulators (HOTIs) in two-dimensional (2D) systems and bring a new physical perspective and application prospect to HOTI. However, the current research on TPSs is limited to periodic structures and Hermitian systems. The special structure of quasicrystals and the skin effect in non-Hermitian systems may bring new physical phenomena to TPSs. In this paper, the TPSs are discovered in non-Hermitian quasicrystals, and the consistency between the two point vacancies for TPSs and the two ends of a 1D topological chain is demonstrated. TPSs will provide a method for the localization control of non-Hermitian quasicrystals.

The coupling between ferroelectricity and ferromagnetism in two-dimensional (2D) materials provides a promising pathway for the realization of electric-field-controlled spintronic devices. In this work, we unveil the microscopic mechanism underlying polarization-dependent magnetic anisotropy in the ferroelectric monolayer ${\mathrm{InCrTe}}_3$ through first-principles calculations. The monolayer ${\mathrm{InCrTe}}_3$, composed of five atomic sublayers with a ${\mathrm{Te}}_{\mathrm{I}}$-Cr-${\mathrm{Te}}_{\mathrm{II}}$-In-${\mathrm{Te}}_{\mathrm{III}}$ stacking sequence, exhibits two inequivalent polar states: a metallic $\mathrm{P}\uparrow$ state with tetrahedral Cr-Te coordination and an insulating $\mathrm{P}\downarrow$ state with octahedral coordination. We show that a substantially larger out-of-plane magnetic anisotropy energy (MAE) in the $\mathrm{P}\uparrow$ state arises from structural transformation and electronic reconstruction associated with a polar structural transition. In the metallic $\mathrm{P}\uparrow$ state, the central ${\mathrm{Te}}_{\mathrm{II}}$ atom undergoes a pronounced out-of-plane distortion, driving its $p$ orbitals closer to the Fermi level. The resulting hybridization between ${\mathrm{Te}}_{\mathrm{II}}\text{−}p$ and Cr-$d$ states enhances spin-orbit coupling (SOC), positioning ${\mathrm{Te}}_{\mathrm{II}}$ as a key SOC hotspot responsible for the large out-of-plane MAE. In contrast, in the insulating $\mathrm{P}\downarrow$ state, the more symmetric octahedral crystal field shifts the Te-$p$ states to lower energies, suppressing orbital mixing and reducing the out-of-plane MAE. These findings provide insight into how polar structural changes can modulate SOC-driven magnetic anisotropy through orbital engineering, offering a microscopic design principle for electrically controllable 2D multiferroic and spintronic devices.

The moderate synthesis conditions of $\mathrm{Ce}{\mathrm{H}}_9$ under cold compression demonstrate its remarkable chemical precompression effect, while the single occupied $4f$ electron configuration of Ce contributes to the rich chemical and physical properties observed in cerium-bearing compounds. In collaboration with machine-learning-accelerated crystal structure prediction, we predicted a thermodynamically stable superconducting phase $\mathrm{CeS}{\mathrm{c}}_2{\mathrm{H}}_{24}$ at 200 GPa. With considering more accurate quantum anharmonic effects, the thermodynamically stable pressure of $\mathrm{CeS}{\mathrm{c}}_2{\mathrm{H}}_{24}$ is further decreased to 117 GPa, at which pressure it exhibits a high superconducting critical temperature ($T_{\mathrm{c}}$) of ∼210 K. We found a different framework of bonding theory for hydrogen-based superconductors where strong metallic bonds in hydrides originate from near-free electronic states between the highest effective energy level and the Fermi level. Specifically, the delocalization of Ce-$4f$ orbitals in $\mathrm{CeS}{\mathrm{c}}_2{\mathrm{H}}_{24}$ provided a number of near-free electrons, thereby greatly enhancing metallic bonds and making the system energetically much more favorable. Our theory for $\mathrm{CeS}{\mathrm{c}}_2{\mathrm{H}}_{24}$ emphasizes the non-negligible role of metallic bonding in hydrides, which paves the way for developing high-temperature superconductors under experimentally accessible pressures.

Quantum fluctuations in low-spin $(S=\frac{1}{2})$ systems make them potential materials to investigate various intriguing field-induced quantum phenomena. In this context, rare-earth $\left(4f\right)$-based effective spin $(J_{\mathrm{eff}}=\frac{1}{2})$ systems with localized magnetic moments and low energy scales offer an advantage of low critical fields and provide access to probe the complete magnetic phase diagram. Here, we present inelastic neutron scattering (INS) data to understand the crystal field (CF) scheme of the previously established $J_{\mathrm{eff}}=\frac{1}{2}$ antiferromagnet ${\mathrm{NdVO}}_4$, along with low-temperature magnetization and heat capacity measurements to construct the complete magnetic phase diagram. Our INS data validate the presence of the $J_{\mathrm{eff}}=\frac{1}{2}$ state at low temperatures with the ground and first excited CF state separated by an energy of 140 K. Furthermore, it yields a unique CF scheme where the excitation corresponding to the highest (fourth) CF state is observed via transitions involving the first and second excited states. Magnetic and heat capacity measurements yield the presence of a field-induced first-order spin-flop transition within the second-order antiferromagnetic (AFM) state. Magnetic phase diagrams constructed using the field-dependent magnetization and magnetic heat capacity reveal a continuous transformation from AFM to spin-flop state with a critical field of $H_{\mathrm{sf}}\sim 1.4\mathrm{T}$. The presence of quantum fluctuations near $H_{\mathrm{sf}}$ are evident from the V-shaped region in entropy contours indicating the presence of accumulated entropy.

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.