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.

The amplitude of charge-to-spin conversion, namely, the spin Hall effect (SHE), in bismuth (Bi) strongly depends on its crystal orientation. The conversion efficiency at room temperature in rhombohedral (110) bismuth is notably large, as expected from its large spin-orbit interaction, and such a large SHE is ascribed to the large effective $g$ factor in bismuth [Fukumoto et al., Proc. Nat. Acad. Sci. USA 120, e2215030120 (2023)]. Despite the successful observation of the large conversion efficiency, a more detailed physical mechanism of the SHE in (110) bismuth is still elusive and under debate. In this work, we investigate the temperature dependence of charge-to-spin conversion in an epitaxial $\mathrm{Bi}\left(110\right)/\mathrm{Ni}$ bilayer system using the second harmonic Hall method, revealing that both spin Hall conductivity and spin diffusion length augment with decreasing temperature. This finding suggests that spin scattering in (110) bismuth is dominated by the Elliott-Yafet mechanism, and the charge-to-spin conversion is mainly attributed to skew scattering.

We report an experimental study of spin-wave modes in individual cylindrical nanowires, a textbook situation of confined spin waves in three-dimensional nanomagnetism. We observe discrete modes of thermal spin waves with microfocused Brillouin light scattering, whose frequencies $f$ shift to higher values as the applied longitudinal induction magnetic field $B_z$ increases. Micromagnetic simulations allowed us to associate every $f\left(B_z\right)$ curve to a given spatial mode, labeled with radial and azimuthal indices $\ell$ and $m$.

Controlling the velocity of the acoustic wave is critical for advancing time-domain signal processing. However, current slow acoustic configurations suffer from narrowband and backscattering loss. Here, we propose broadband topologically protected slow acoustic reciprocal systems via multiwinding modulation in the Brillouin zone (BZ). By coupling the resonance-induced nearly flat bands and the topological edge states (TESs), hybridized TESs with multiple windings across the BZ are formed, which result in broadband slow acoustic waves with controllable velocity. The relative bandwidth of $\sim 7\%$ and the velocity of $0.04c_0$ ($c_0$ is the acoustic wave velocity in air) are achieved, which greatly outperforms conventional methods. Our work paves the way for the development of high-performance acoustic devices.

We investigate a many-body interacting system of quantum kicked rotors, where each rotor resides in its respective quantum resonance. Rich many-body dynamics are found to emerge from the interplay between the principal and secondary resonances. In particular, for both the wavepacket and bipartite entanglement entropy, we analytically demonstrate three distinct dynamical regimes—quadratic spreading (growth), period-2 oscillation, and their hybrid—governed by the respective symmetries of the relevant potentials. Based on these symmetries, the connection between the wavepacket and the entanglement dynamics is illustrated. Other related issues are also discussed, including higher-order resonance effects, the robustness of the predicted dynamical behaviors, extension to many-body kicked tops, and relevance to experimental studies.

Magnetoelastic coupling between surface acoustic waves (SAWs), spin waves, and magnetic textures enables tunable magnetoacoustic functionality. Synthetic antiferromagnets (SAFs) provide a suitable platform owing to their adjustable SW spectra and negligible stray fields. Here we investigate how a Bloch-type domain wall (DW) in a CoFeB/Ru/CoFeB SAF modifies SAW propagation. Analytical modeling and micromagnetic simulations show that SAWs in the nonuniform SAF decompose into three magnetoelastic eigenmodes. Near the magnetoelastic resonance, the SAW transmission across the DW displays pronounced frequency-dependent oscillations. We trace this behavior to interference among the eigenmodes, rather than the conventional picture of a DW acting simply as a scattering barrier. These findings identify an interference mechanism in magnetoacoustic transport and point to a route toward frequency-tunable SAW devices based on magnetic domain structures.

Using the density functional theory plus dynamical mean-field theory ($\mathrm{DFT}+\mathrm{DMFT}$) approach, we study the effects of electronic correlations and doping on the normal state electronic structure of the double-layer nickelate superconductor ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ (LNO) under pressure. In agreement with experiments, we obtain significant orbital-dependent quasiparticle renormalizations of the Ni $x^2\text{−}{y}^2$ and $3z^2\text{−}{r}^2$ bands, accompanied by incoherence (bad metal behavior) of the $3z^2\text{−}{r}^2$ states, caused by the proximity of the Ni $3d$ states to orbital-dependent localization. Our results demonstrate a sensitive, nonmonotonic dependence of $m^{*}/m$ on doping, with a remarkable, by about 20%, increase for the Ni $x^2\text{−}{y}^2$ orbitals upon electron doping $x\sim 0.2$ (per Ni ion), implying a significant enhancement of orbital-dependent correlations with oxygen deficiency in LNO. We observe a reconstruction of the low-energy electronic structure of LNO upon doping above $x\sim -0.3$ and 0.2. It is associated with the Lifshitz transition, with a crossover to a self-doping regime characterized by partial occupation of the La $5d$ bands (upon an electron doping $x>0.2$). Our analysis of the static magnetic susceptibility $\chi \left(\mathbf{q}\right)$ obtained within $\mathrm{DFT}+\mathrm{DMFT}$ suggests the possible formation of the spin and charge (or bond) density wave stripes, implying strong spin and charge correlations in LNO. We show that this behavior is associated with the suppression of the Néel $G$-type antiferromagnetic ordering of the ${\mathrm{Ni}}^{2+}$ ions upon hole doping. Interestingly, upon a moderate electron doping of the ${\mathrm{Ni}}^{2.5+}$ ions (e.g., with oxygen deficiency), we find a significant enhancement of the strength of in-plane spin and charge fluctuations. We note a close resemblance of our results to those for the bilayer Hubbard model, which shows the boosting of superconductivity as one of the two electron bands approaches the Lifshitz transition (e.g., upon doping). Our results suggest that spin and charge stripe fluctuations, effectively tuned by doping, play a key role in pressure-driven superconductivity in LNO.

We study electronic properties of the ternary tellurides ${\mathrm{TaXTe}}_4$ (X = Rh, Ir) using density functional theory and investigate chiral anomaly mediated planar Hall response from ab initio calculations. We show that ${\mathrm{TaRhTe}}_4$ is a hybrid Weyl semimetal (WSM), hosting Weyl points (WPs) of both type-I, type-II, and ${\mathrm{TaIrTe}}_4$ is a type-I WSM in absence of spin-orbit coupling (SOC). ${\mathrm{TaRhTe}}_4$ continues to remain a hybrid WSM while ${\mathrm{TaIrTe}}_4$ converts into a type-II WSM under the application of SOC. We observe long Fermi arcs connecting WPs of opposite chirality. We report orbital-driven topological phase transition in ternary tellurides. The WSM phases in ${\mathrm{TaXTe}}_4$ are controlled by the orbital character of the $d_{xz}$ and $d_{z^2}$ states of X = Ir/Rh atoms. Replacing Rh with Ir enhances the $d_{z^2}$ orbital contribution near the Fermi level at the expense of $d_{xz}$ states. This transforms the type-I WPs into type-II resulting in a conversion of hybrid WSM ${\mathrm{TaRhTe}}_4$ to type-II WSM ${\mathrm{TaIrTe}}_4$. This systematic study opens new routes for engineering topological materials relying beyond strong SOC and sheds light on the effect of orbital degree of freedom on the electronic properties of tellurides. We further report an enhancement of planar Hall effects due to orbital-driven topological phase transition in ${\mathrm{TaXTe}}_4$ and we resort to a tight-binding model to correlate the above findings with the velocity modulated off-diagonal effective mass anisotropy in different types of WSMs.

The anomalous Hall effect (AHE) with multi-degree-of-freedom coupling has become a research hot spot in the condensed matter field due to its multiple tunable states, and exploring effective tuning methods for spin, valley, and layer degrees of freedom holds significant research value. Through the first-principles calculations and symmetry analysis, we investigate the properties of bilayer altermagnetic (AM) material $\mathrm{Ca}{\left(\mathrm{CoN}\right)}_2$, which is protected by $S_{4z}$ symmetry, with a particular focus on the influence of interlayer coupling and sliding on the band structure. For bilayer $\mathrm{Ca}{\left(\mathrm{CoN}\right)}_2$ with interlayer antiferromagnetic (AFM) coupling, the interlayer opposite spin sublattices can be connected by symmetries such as $S_{4z}$, classifying it as an AM system. In contrast, systems with interlayer ferromagnetic (FM) coupling belong to the fully compensated ferrimagnetism category. Interlayer sliding breaks the $S_{4z}$ symmetry of the system, thereby controlling the coupling of spin, valley, and layer degrees of freedom. Sliding along the $x$ or $y$ axis breaks the $S_{4z}$ symmetry, inducing opposite valley polarization and layer polarization, which further leads to layer-locked Berry curvature and spin-valley-layer polarized AHE. Bilayer systems with interlayer AFM coupling can switch the spin, valley, and layer degrees of freedom via sliding, while those with interlayer FM coupling can only switch the valley and layer degrees of freedom. This work reveals the sliding rules of bilayer AM systems protected by $S_{4z}$ symmetry and expands the implementation methods for AHE with multi–degree of freedom tunability.

Accurate phonon transmission coefficients are essential for controlling heat transport and designing phononic metamaterials. Conventional models for computing transmission coefficient are based on plane-wave solution and spectrum weighting, limiting their ability to capture actual phonon transport dynamics in multi-interface heterostructures. Here we develop an analytical framework that incorporates spatial coherence and validate it against time-domain wave-packet simulations. We show that spatial coherence strongly affects transmission in multi-interface systems, whereas it is negligible for a single interface. The developed framework is robust for various wave-packet profiles and can accurately resolve both transmission coefficient and the wave-packet dynamics in realistic multi-interface heterostructures. Our work provides a robust framework for exploring coherence effects in phonon transport, which may offer guidelines for thermal management and design of phononic metamaterials.

We present a finite-strain model that is capable of describing the large deformations in bent nanowire heterostructures. The model incorporates a nonlinear strain formulation derived from the first Piola-Kirchhoff stress tensor, coupled with an energy functional that effectively captures the lattice-mismatch-induced strain field. We use the finite element method to solve the resulting partial differential equations and extract cross-sectional maps of the full strain tensor for both zinc-blende and wurtzite nanowires with lattice-mismatched core and one-sided stressor shell. In either case, we show that the bending is essentially exclusively determined by ${\varepsilon }_{zz}$. However, the distinct difference in shear strain has important consequences with regard to both the mechanical deformation and the existence of transverse piezoelectric fields in the nanowires.

The exact dynamics of many-particle quantum systems coupled to an environment is governed by the Kadanoff-Baym equations, which describe the time evolution of Green's functions containing both population and spectral information. While these equations can, in principle, be solved exactly for small systems, the numerical cost grows rapidly and becomes prohibitive for longer times or larger systems. Beyond many-body correlations, the primary computational challenge arises from memory effects, which cause the numerical complexity to scale cubically with physical time. In certain cases, this scaling can be reduced to linear by reconstructing the lesser and greater Green's function components from the electron density, however, at the expense of losing spectral information. It is demonstrated here that the Kadanoff-Baym equations for open systems can be solved numerically exactly with optimal quadratic time scaling, without introducing any approximations. This result significantly extends the feasibility of nonequilibrium simulations and provides a simple, exact benchmark for testing approximate methods.

We studied double-layer $\mathrm{WS}{\mathrm{e}}_2$ stacked on opposite sides of thin layers of hexagonal Boron nitride with different densities of electrons and holes. For a fixed hole density, the Coulomb drag resistance is found to exhibit plateaus approximately equal to −$h$/($4e^2$) and −$h$/($2e^2$) as the electron density is changed. When the number of electrons is equal to the number of holes, an exciton solid forms whose transport of quantum edge defects gives rise to the drag resistance. When the electron and hole densities are different, the excess electrons form a solid embedded in the exciton solid. The Coulomb drag resistance of the exciton solid comes from the one-dimensional transport of the two lowest energy channels of quantum edge vacancy-interstitial pairs. This corresponds to the first plateau. With the embedded solid, one of these channels is blocked. This corresponds to the second plateau. Transport experiments in the Corbino geometry with no edges and extra heavier holes were carried out. The plateaus disappeared. Three peaks in the resistance at different hole densities were observed. We interpret that the three peaks correspond to the commensurate exciton and two classes of hole solids. We performed phonon calculations of these states and found that the stability of these exciton-based quantum solids shows good agreement with experiment. Our results establish classes of extreme quantum solid states, opening additional avenues for the study of strongly correlated quantum transport phenomena involving quantum defect states.

$\mathrm{Hf}{\mathrm{O}}_2$ thin films are recognized as pivotal materials for next-generation ferroelectric memories, and extensive experimental efforts have been dedicated to defect-engineering $\mathrm{Hf}{\mathrm{O}}_2$-based systems towards tailored ferroelectric properties. However, the microscopic mechanisms through which excess electrons modulate the defect states and doping behavior in $\mathrm{Hf}{\mathrm{O}}_2$ remain not fully understood, which has slowed progress in the field. To fill this gap, we investigate the interaction mechanisms between aliovalent dopants and oxygen vacancies ($V_{\mathrm{O}}$) in $\mathrm{Hf}{\mathrm{O}}_2$ by subspace corrected (PBE+$U$ functional) density functional theory simulations. Our results reveal that the extra charge introduced by trivalent dopants forms a small polaron localized on a tricoordinated oxygen atom, producing a deep empty defect state within the $\mathrm{Hf}{\mathrm{O}}_2$ band gap. This deep defect state can interact with the excess electrons generated by oxygen vacancies, thereby enhancing the stability of the three-coordinated oxygen vacancy ($V_{\mathrm{O}3}$) configuration compared to the four-coordinated one ($V_{\mathrm{O}4}$). The introduction of $V_{\mathrm{O}4}$ lowers the local polarization-switching barrier near a statistical accumulation of vacancies by 13%, while $V_{\mathrm{O}3}$ produces a more pronounced reduction of 60%, corresponding to a minimum barrier of 0.12eV/u.c. The stabilized $V_{\mathrm{O}3}$ center effectively reduces the ferroelectric switching barrier in the $\mathrm{Pca}{2}_1$ phase by promoting reduced atomic displacements and lattice distortions, significantly decreasing the coercive field of $\mathrm{Hf}{\mathrm{O}}_2$. These findings provide critical insights for advancing the fundamental understanding of $\mathrm{Hf}{\mathrm{O}}_2$ materials and establishing design guidelines for constructing defect-tolerant ferroelectric devices through targeted defect engineering.

Research on twin boundaries (TBs) in molecular crystals has primarily emphasized their effect on mechanical properties and applications, with limited focus on microstructural details. Twin identification typically relies on extensive experiments, lacking reliable computational predictions. Here, we extend to molecular crystals the previously developed evolutionary methodology for predicting grain boundary structures in atomic crystals. To achieve that, care must be taken of molecular orientations, conformations, and grain displacements during global optimization. We apply this method to predict possible TBs on the (100), (010), and (001) planes of polymorph I of aspirin; the (100), (010), (001), (102), (110), and (210) planes of α-RDX; and the (010), ($10\overline{1}$), (011), (101), and (110) planes of β-HMX. For HMX, the lowest-energy (101) TB matches experimentally reported twin, validating our approach. We predict unexpected low-energy TB configurations, including a unique cluster-like structure on (100) plane of aspirin and numerous conformational changes in RDX. Finally, we discuss the characteristics and patterns of molecular crystal twin formation.