Ferroelectric switching governs the functional properties of ferroelectric perovskites. It is widely accepted that this switching depends on domain nucleation and pinning and that these processes can be controlled by the defect structure. However, an atomistic picture of the influence of one important class of defects—dislocations—on ferroelectric switching is missing. This is an important gap in knowledge as dislocations cannot be avoided at interfaces and can also be engineered by plastic deformation at high temperatures. Using atomistic simulations, we show how the cores of $\langle 100\rangle$ edge dislocations in ${\mathrm{BaTiO}}_3$ can either act as nucleation centers for ferroelectric switching or pin walls depending on the direction of the applied field. The coupling between the electric field and polarization is strongest when the field is applied parallel to the Burgers vector of the dislocation.

Tensor-network renormalization group (TNRG) is an efficient real-space renormalization group method for studying the criticality in both classical and quantum lattice systems. Exploiting symmetries of a system in a TNRG algorithm can simplify the implementation of the algorithm and can help produce correct tensor RG flows. Although a general framework for considering a global on-site symmetry has been established, it is still unclear how to incorporate a lattice symmetry in TNRG. As a first step for lattice symmetries, we propose a method to incorporate the lattice-reflection symmetry in the context of a TNRG with entanglement filtering in both two and three dimensions (2D and 3D). To achieve this, we write down a general definition of lattice-reflection symmetry in tensor-network language. Then, we introduce a transposition trick for exploiting and imposing the lattice-reflection symmetry in two basic TNRG operations: projective truncations and entanglement filtering. Using the transposition trick, the detailed algorithms of the TNRG map in both 2D and 3D are laid out, where the lattice-reflection symmetry is preserved and imposed. Finally, we demonstrate how to construct the linearization of the TNRG maps in a given lattice-reflection sector, with the help of which it becomes possible to extract scaling dimensions in each sector separately. Our work paves the way for understanding the lattice-rotation symmetry in TNRG.

The mechanisms by which isolated interacting quantum systems evade thermalization extend beyond disorder-induced many-body localization, encompassing a growing class of interaction-driven phenomena. We investigate a spin-$\frac{1}{2}$ ladder with asymmetric XY leg couplings and tunable Ising interactions on the rungs, and identify the microscopic origin of quasi many-body localization (quasi-MBL) in this setting. Through a suite of diagnostics—including entanglement dynamics, fidelity susceptibility, adiabatic gauge potential norms, level-spacing statistics, and entropy of eigenstates—we uncover a reentrant progression of dynamical regimes as the rung coupling $J_z$ is varied: integrable behavior at $J_z=0$, quantum chaos at intermediate $J_z$, and a robust nonthermal regime at strong coupling. In the latter regime, we demonstrate the emergence of a reversed quantum disentangled liquid (reversed-QDL), where the light species thermalizes while the heavy species remains localized. The strong-coupling limit further yields emergent local integrals of motion anchored in a fixed-point structure, providing a microscopic origin of the observed quasi-MBL dynamics. These results establish reversed-QDL as a distinct, disorder-free route to nonergodicity and broaden the classification of dynamical phases in quantum matter.

We determine the free energy of strongly correlated electron systems in the example of the Hubbard model by calculating the contribution of spin and charge fluctuations to the Gutzwiller approximation mean-field result. We employ the slave-boson formulation of Kotliar and Ruckenstein in its spin-rotation-invariant form in the usual continuous-time approximation of the functional integral representation, corrected by “high-frequency contributions” ($\mathrm{SRIKR}+$). In contrast to all previous attempts to calculate the fluctuation contribution to the free energy within the spin-rotation-invariant Kotliar-Ruckenstein slave-boson representation (SRIKR) scheme our result preserves the noninteracting limit. We show that the correct form of the kinetic energy renormalization is essential. The results for the ground-state energy in the paramagnetic phase are in very good agreement with state-of-the-art results obtained by methods such as density matrix embedding theory, quantum Monte Carlo, and others. The leading low-temperature behavior of the free energy allows us to extract the quasiparticle effective mass, in particular its enhancement near a continuous phase transition into an ordered state. Our work demonstrates that the $\mathrm{SRIKR}+$ method is competitive with the best available alternative methods and equips the slave-boson approach with an improved synoptic power to explore strongly correlated electron systems.

Two-terminal spintronic devices remain challenging to model under realistic operating conditions, where the interplay of complex electronic structures, correlation effects, and bias-driven nonequilibrium dynamics may significantly impact charge and spin transport. Existing ab initio methods either capture bias-dependent transport but neglect dynamical correlations or include correlations but are restricted to equilibrium or linear-response regimes. To overcome these limitations, we present a framework for steady-state quantum transport, combining density functional theory (DFT), the nonequilibrium Greens' function (NEGF) method, and dynamical mean-field theory (DMFT). The framework is then applied to Cu/Co/vacuum/Cu and an Fe/MgO/Fe tunnel junction. In Co, correlations drive a transition from Fermi-liquid to non-Fermi-liquid behavior under finite bias, due to scattering of electrons with electron-hole pairs. This leads to incoherent contributions to the conductance that are observable in scanning tunneling spectroscopy experiments. In contrast, in the Fe/MgO/Fe junction, correlation effects are weaker: Fe remains close to equilibrium even at large biases. Nevertheless, inelastic scattering can still induce partly incoherent transport that modifies the device's response to the external bias. Overall, our framework provides a route to model spintronic devices beyond single-particle descriptions, while also suggesting new interpretations of experiments.

We employed a first-principles many-body approach to investigate the linear optical and second-order nonlinear harmonic generation spectra of $n\text{−}A\mathrm{P}$ ($n=\alpha ,\beta ,\gamma$; $A=\mathrm{C},\mathrm{Si}$; $\mathrm{P}=\text{phosphorus}$) monolayers. All the monolayers exhibit energetic, dynamical, thermal, and mechanical stability. Incorporating excitonic effects leads to a pronounced enhancement in both the linear and SHG responses. The dielectric spectra show absorption capability of these monolayers in the 2–5 eV energy range, covering a broad spectral region. Among these monolayers, α-SiP was found to have the largest static second-order susceptibility values of 374 pm/V along with an extremely large SHG coefficient of 2.4 nm/V at 0.8 eV, at the $G_0{W}_0$-BSE level of theory. Also, $\beta \text{−}\mathrm{SiP}$ exhibits a prominent SHG peak at ∼2 eV, whereas γ-CP monolayer exhibits at ∼4 eV, indicating these monolayers have the potential to generate light in a broad spectral range from infrared to deep ultraviolet region, making them promising candidates for nonlinear optical SHG applications.

We present a comprehensive study of the magnetic, thermodynamic, and transport properties of single-crystalline TbRhPb, a geometrically frustrated rare-earth compound that crystallizes in the noncentrosymmetric ZrNiAl-type structure, where ${\mathrm{Tb}}^{3+}$ ions form a quasikagome arrangement in the $ab$ plane. Temperature-dependent magnetization measurements reveal two successive antiferromagnetic transitions at $T_{N1}\approx$ 21 K and $T_{N2}\approx$ 12.4 K. For $H\perp c,\chi (T$) shows two broad humps at $\approx$ 60 and 110 K due to the presence of the crystal electric field (CEF) effect. Our CEF analysis shows the 13-fold degenerate ground state of the ${\mathrm{Tb}}^{3+}$ ion split into five singlets and four doublets with an overall splitting $\approx$ 277 K. Isothermal magnetization for $H\perp c$ display two steplike metamagnetic transitions with small hysteresis, whereas no such features appear for $H\parallel c$ in the ordered state, highlighting strong magnetic anisotropy. Heat-capacity and resistivity measurements confirm the magnetic ordering and indicate gapped-magnon behavior below $T_{N2}$. The resulting magnetic field-temperature ($H-T$) phase diagram indicates a complex magnetic ground state. In addition, transport measurements show metallic behavior with low carrier density and large, anisotropic magnetoresistance. First-principles calculations identify an in-plane AFM ground state and reveal linear band crossings that form nodal-line features near the Fermi level. Together, these results suggest that TbRhPb is a promising antiferromagnetic topological semimetal candidate.

We establish the conditions under which a conservation law associated with a noninvertible operator may be realized as a symmetry in quantum physics. As established by Wigner, all quantum symmetries must be represented by either unitary or antiunitary transformations. Relinquishing an implicit assumption of invertibility, we demonstrate that the fundamental invariance of quantum transition probabilities under the application of symmetries mandates that all noninvertible symmetries may only correspond to projective unitary or antiunitary transformations, i.e., partial isometries. This extends the notion of physical states beyond conventional rays in Hilbert space to equivalence classes in an extended, gauged Hilbert space, thereby broadening the traditional understanding of symmetry transformations in quantum theory. Our generalized theorem applies irrespective of the origin of the (non)invertible symmetry, holds in arbitrary spatial dimensions, and is independent of the Hamiltonian or action. We explore its physical consequences and, using simple model systems, illustrate how the distinction between invertible and noninvertible symmetries can sometimes be tied to the choice of boundary conditions.

Cluster dynamical mean-field theory (CDMFT) with an exact diagonalization (ED) impurity solver faces exponential scaling limitations from the Hilbert space dimension. We introduce subbath CDMFT, an alternative to the conventional ED-CDMFT method in which the discrete bath is subdivided into separate subbaths, each coupled to the cluster with distinct hybridization functions. In this approach, only one subbath at a time is actively involved in ED, dramatically reducing the computational cost by replacing a single large impurity problem with multiple smaller separate ones. Our method successfully reproduces key physical properties including particle-hole symmetry and Mott physics, while allowing for an extended bath representation at a fraction of the typical computational cost.

We investigate the spectral properties of doped one-dimensional excitonic insulators. Employing matrix-product-state-based methods, we compute the single-particle spectrum and optical conductivity in a correlated two-band model. Our numerical calculation reveals the emergence of a correlation-driven in-gap branch in the doped state. The origin of the in-gap branch is examined by decomposing the propagation dynamics of a single particle, elucidating that the doping-induced branch is associated with excitonic correlations. Our demonstrations suggest that the doping-induced branch can serve as an indicator of electron-hole correlations.

Understanding orientation dependent phonon transport is essential for optimizing heat dissipation in crystalline heterostructures for advanced electronic applications. However, the intrinsic and extrinsic mechanisms governing the degree of orientation dependent interfacial thermal conductance ($G$) remain insufficiently understood. Here, we systematically elucidate the fundamental mechanisms of orientation dependent heat transport across $\mathrm{Al}/\alpha \text{−}\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$ interfaces based on ultrafast pump-probe thermal conductance measurements and nonequilibrium molecular dynamics (NEMD) simulations. For nonideal $\mathrm{Al}/\alpha \text{−}\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$ interfaces prepared by thermal evaporation or magnetron sputtering, we observe only a weak orientation dependence in $G$, while intrinsic $\mathrm{Al}/\alpha \text{−}\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$ interfaces reveal a strong dependence, with a conductance ratio of approximately 1.8−2.4 across different crystallographic orientations. We attribute this intrinsic orientation dependence to anisotropy in phonon group velocity, i.e., the phonon focusing effect. In contrast, we demonstrate that the suppressed orientation dependent $G$ in nonideal $\mathrm{Al}/\alpha \text{−}\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$ interfaces results from an ultrathin amorphous layer on $\alpha \text{−}\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$ surfaces prior to Al deposition. This ultrathin amorphous layer acts as an isotropic filter, masking the angular dependence of phonon transmission from $\alpha \text{−}\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$ to Al, effectively obscuring the role of interfacial bonding strength. Furthermore, the weak orientation dependence persists down to 80 K, indicating that the amorphous layer strongly influences phonons transport across the entire frequency spectrum, including the low-frequency modes. This work advances the understanding of orientation dependent interfacial heat transport in nonideal metal/semiconductor interfaces, and thus is beneficial to the thermal management for crystalline heterostructures electronics devices.

We explore the emergence of topological phases in moiré ${\mathrm{MoTe}}_2/{\mathrm{WSe}}_2$ bilayer, highlighting the crucial role of spin-orbit coupling and Coulomb interactions at two holes per moiré unit cell $v=2$. Our analysis uncovers robust quantum valley Hall insulating phase and reveals that long-range interactions alone can mediate the interlayer electron tunneling, generating topologically nontrivial bands even in the absence of the corresponding single-particle hopping. Additionally, we show that in the case of band mixing terms originating both from the interaction and single-particle physics, a competition between topological states realizing $s$-wave and $(p\pm ip)\text{-wave}$ symmetries can appear. Moreover, within the considered theoretical framework, we present that by introducing a small Zeeman field, one can lift the band inversion in one of the valleys. This leads to a quantum anomalous Hall insulating state with the topological gap opening in a single valley and the other being topologically trivial.

A Coulomb blockade (CB) arises in nanoscale systems with ultrasmall capacitance, where discrete charging effects dictate electron transport, enabling wide-ranging applications based on single-electron transistors. Despite established electrostatic control of charge states in quantum dots and nanoislands, a rigorous quantitative link between junction parameters and the CB spectrum remains elusive. Here, using scanning tunneling spectroscopy, we investigate the spatial variation of CB in indium nanoislands on semiconducting black phosphorus. We observe spatially dispersive charging resonances whose trajectories exhibit a finite shift of the symmetry axis in bias as well as a pronounced asymmetric curvature. By comparing the experimental results with calculations based on orthodox theory, we show that these features originate from work function differences in the junctions, underscoring the importance of junction-specific electrostatics in nanoscale charge transport.

Heavy-fermion systems have attracted extensive attention as platforms for investigating exotic quantum phenomena, ranging from quantum criticality to unconventional superconductivity. Substantial efforts have focused on modulating quantum phases by dimensional reduction, representing a long-standing challenge for conventional heavy-fermion compounds with three-dimensional crystal and electronic structures. Here, we report the transport properties of bulk and nanoflake samples of CeSiI, a van der Waals antiferromagnet that has been established as a heavy-fermion metal. Magnetic torque and magnetoresistance measurements reveal two metamagnetic transitions at ${\mu }_{0}H\approx 2.4$ and $4.2\mathrm{T}$. Zero-field out of plane and in-plane electronic transport measurements indicate a heavy-fermion behavior with $T^2$-linear dependence on resistivity in the antiferromagnetic state. As the magnetic field increases, the antiferromagnetic state is gradually suppressed, and the resistivity deviates from the $T^2$-linear relationship simultaneously; this suggests a deeper underlying coupling between the heavy-fermion behavior and the antiferromagnetic order. These two features persist down to the nanoflakes, but the metamagnetic transitions are suppressed by proton gating. Our work establishes CeSiI as an ideal platform for investigating the interplay between Kondo screening and magnetic order in bulk crystals and as a potential building block for engineering two-dimensional heterostructures.

We study self-energy effects induced by strong magnetic fluctuations in the paramagnetic phase of strongly correlated itinerant magnets within the density-functional theory combined with the dynamical mean-field theory ($\mathrm{DFT}+\mathrm{DMFT}$ approach) and its nonlocal extension. We show that both local and nonlocal magnetic correlations yield a splitting of the electronic spectrum in the paramagnetic phase, such that it closely resembles the DFT band structure in the ordered phase. We demonstrate these effects on $\alpha$-iron, half-metal ${\mathrm{CrO}}_2$, van der Waals material ${\mathrm{CrTe}}_2$, and altermagnet CrSb. Although the obtained split bands do not possess a certain spin projection, their splitting suppresses spectral weight at the Fermi level. Even when originating from local magnetic correlations, the splitting is strongly momentum dependent as a consequence of the orbital selectivity of nonquasiparticle states. The relative importance of nonlocal vs local correlations depends on the proximity to half filling of $d$ states: closer to half filling, the role of local correlations increases.

The origin of intrinsic stress in amorphous and structurally disordered carbon films remains a fundamental challenge. Numerous previous studies have focused on deposition parameters and their relationship with stress, resulting in the hypothesis that a high ${\mathrm{sp}}^3$-C fraction is a key factor governing compressive stress. However, the precise role of geometrical parameters in stress generation is still unknown. Here, we show that intrinsic stress is mainly dominated by two geometrical parameters: standardized bond length and density, followed by ${\mathrm{sp}}^3$-C fraction. We found that the high ${\mathrm{sp}}^3$-C fraction independently contributes to tensile stress, contrary to previous experimental results. A data-driven assisted investigation of various amorphous carbon models prepared using first-principles calculations quantitatively revealed the effect of each parameter by isolating their contributions. As a result, a generalized formula is proposed to correlate the intrinsic stress and fundamental structural parameters.

The interplay between unitary dynamics and quantum measurements induces diverse phenomena in open quantum systems with no counterparts in closed quantum systems at equilibrium. Here, we generally classify Kraus operators and their effective non-Hermitian dynamical generators, thereby establishing the tenfold classification for symmetry and topology of monitored free fermions. Our classification elucidates the role of topology in measurement-induced phase transitions and identifies potential topological terms in the corresponding nonlinear sigma models. Furthermore, we establish the bulk-boundary correspondence in monitored quantum dynamics: nontrivial topology in spacetime manifests itself as topologically nontrivial steady states and gapless boundary states in Lyapunov spectra, such as Lyapunov zero modes and chiral edge modes, leading to the topologically protected slowdown of dynamical purification.