We investigate the transport properties of Majorana zero modes (MZMs) and Majorana Kramers pairs (MKPs) in one-dimensional topological superconductors, respectively. An effective model is established for the braiding of MZMs and MKPs. We employ $d_{x^2-y^2}$-wave topological superconductors to embody the effective model for the braiding of MKPs by utilizing the finite-size effect and minimal locally tunable coupling parameters. We show how to construct the state initialization and readout via gate control. We also use this method for the braiding of MZMs in $s$-wave topological superconductors. Our proposal presents a promising avenue for experimentally verifying the non-Abelian statistical properties of MZMs and MKPs, with implications for topological quantum computing.

Alkali halides are prototypical ionic solids whose refractive index is a fundamental property related to their lattice structure and ionic polarizability. In particular, lithium fluoride (LiF) has the largest band gap of any known transparent material and maintains transparency at high pressures, making it well suited for use as an optical window in dynamic compression experiments. While empirical fits to the measured density dependence of the refractive index have been provided, a model that is valid over the entire pressure range of experiments and based on a polarization-based theoretical description is lacking. We present a refractive index model for dynamically compressed LiF based on the Lorentz-Lorenz equation, where the molecular polarizability is determined using a single oscillator model with a strain polarizability parameter $\mathrm{\Lambda }=0.73$. We show that our modeling approach provides an excellent match to the LiF refractive index data for both shock and ramp compression experiments to 900 GPa (density compression greater than threefold). Additionally, updated fits are provided to determine the refractive index correction for LiF windows used in dynamic compression experiments.

Recently synthesized diamond-graphite nanocomposites, consisting of diamond and graphite nanodomains interlocked via coherent interfaces (termed gradia), exhibit an impressive combination of ultrahigh hardness and superior toughness [Luo et al., Nature (London) 607, 486 (2022)]. This extraordinary finding challenges the prevailing understanding of the widespread trade-off relationship in strong covalent solids, while the toughening mechanism of gradia remains mysterious. Here, we unveil an $s{p}^2\text{−}s{p}^3$ interconversion mechanism, where the graphitization or the bond failures are effectively suppressed through layer-by-layer migration of the interfaces towards diamond (or graphite) domains, which originates from the sequential metallization starting from the diamond atomic layers adjacent to the interface with weakened $s{p}^3$ hybridization and the associated inverse process, i.e., metal-semiconductor transition of graphite domain ($s{p}^2$ to $s{p}^3$ hybridization). These interface-mediated continuous changes in the localized bonding pattern greatly promote the strain-energy dissipation, leading to a profound tolerance for large strains. Moreover, a size-dependent toughening is demonstrated, attributed to detrimental graphitization and interfacial bond breakage that occur under critically small $s{p}^2/s{p}^3$ thickness. These findings provide guidance for the experimentally rational design of gradia, and the toughening mechanisms arising from interface-induced electronic structure transition also sheds light on the toughening of other hard but brittle materials through heterophase junctions.

Strategically manipulating defect dynamics in a crystalline solid can modulate lattice vibrations, thereby reducing thermal transport through the lattice and making it suitable for diverse applications such as thermoelectrics. However, purposefully increasing the concentration of defects often leaves an adverse effect on the charge-carrier mobility, which drags down its thermoelectric performance. Here, to address this challenge, we have devised a strategy to suppress the lattice thermal conductivity (${\kappa }_L$) without hampering the charge-carrier transport to achieve an improved thermoelectric figure of merit, $z$, in $\mathrm{S}{\mathrm{b}}_2\mathrm{T}{\mathrm{e}}_3$ by creating anion vacancy. Successful creation of Te vacancy is confirmed by synchrotron x-ray diffraction study and extended x-ray absorption fine-structure measurements. With increasing Te vacancy, a substantial decrease in ${\kappa }_L$ is observed with the lowest ${\kappa }_L\sim 0.75\mathrm{W}{\mathrm{m}}^{-1}{\mathrm{K}}^{-1}$ obtained at room temperature for 10 mol. % Te-vacant sample. Our attempt to fit the ${\kappa }_L$ data by the Debye-Callaway model divulges that anion vacancy makes the lattice more anharmonic and introduces significant point defects which suppress the conduction of phonons. The density of vacancy-induced dislocations in tellurium-vacant samples increases, leading to heightened scattering of heat-carrying phonons. Despite a noteworthy decrease in ${\kappa }_L$, the charge-carrier mobility remains nearly unaffected, resulting in an enhanced thermoelectric performance in the Te-deficient $\mathrm{S}{\mathrm{b}}_2\mathrm{T}{\mathrm{e}}_3$ sample.

We investigated spin-orbit-torque (SOT) efficiency in a crystalline (Ga,Mn)(As,P) ferromagnetic film with out-of-plane anisotropy. By performing Hall resistance measurements with opposite current polarities, we identified current-induced SOT effects in magnetization transition. The SOT efficiency was then quantified by analyzing hysteresis shifts as a function of in-plane magnetic bias fields. We found that SOT efficiency depends on crystal direction along which current flows, consistent with the dependence of net spin-orbit fields (SOFs) in tensile-strained (Ga,Mn)(As,P) film. The highest efficiency (7.4 Oe/${10}^5\mathrm{A}\mathrm{c}{\mathrm{m}}^{-2}$) was observed for the $\left[1\overline{1}0\right]$ current direction, for which Dresselhaus- and Rashba-type SOFs are parallel and of the same sign in the film. Additionally, the SOT efficiency showed saturation behavior as a function of in-plane bias field, which suggests the presence of Dzyaloshinskii-Moriya interaction in the (Ga,Mn)(As,P) film due to its noncentrosymmetric crystal structure.

We report on the magnetic structures of ${\mathrm{PrMn}}_7{\mathrm{O}}_{12}$, resolving both a high-temperature structure in common with the other $R^{3+}{\mathrm{Mn}}_7{\mathrm{O}}_{12}$ systems and an additional low-temperature phase characterized by a superposed incommensurate (ICM) spin canting. A phenomenological model is developed to account for large magnetoelastic coupling immediately below the Curie temperature, demonstrating that $A^{\prime }B$ exchange is primarily responsible for the ferrimagnetic structures observed across the $R^{3+}{\mathrm{Mn}}_7{\mathrm{O}}_{12}$ family. Finally, an analytical mean-field minimal model is presented that successfully accounts for all magnetic structures observed in this family of materials, including the canted commensurate and ICM ground states.

The electronic and magnetic properties of a recently synthesized perovskite phase of ${\mathrm{HgMnO}}_3$ are studied. By means of ab initio density functional theory calculations this material was shown to be altermagnetic. We discuss the features of its electronic structure and unveil the physical mechanism of the anomalous suppression of the antiferromagnetic exchange interaction in this material. While it is tempting to ascribe the unexpectedly weak exchange interaction between nearest neighbors to crystal structure distortions, this is an indirect ferromagnetic exchange via Hg $6s$ states, which strongly affects the magnetic properties. This effect can be important not only for ${\mathrm{HgMnO}}_3$, but also for many other transition metal compounds having empty $s$ states, placed not far above the Fermi level.

We investigate the electronic and structural zero-temperature properties of the $\alpha$ phase of solid oxygen at pressures ranging from 0 to 6 GPa. Crystal and electronic structures have been characterized using a generalized gradient approximation combined with a semiempirical van der Waals dispersive interaction and a Hubbard $U$ correction. Lattice parameters, volume-pressure relation, compressibility, dispersion curve, density of states, and phonon frequencies are studied under pressure and indicate a marked sensitivity with the considered electronic model. A systematic comparison of the various parameters permits one to determine an optimized scheme that reproduces the experimental behavior with pressure and represents a clear improvement with respect to previous simulations and phenomenological models.

We discuss the rapidly rotating states of a superfluid. We concentrate on the giant-vortex (GV) state, which is a coherent rotating solution with a macroscopic hole at the center. We show that, for any trap, the fluctuations obey an approximately chiral dispersion relation, describing arbitrary shape deformations moving with the speed of the ambient superfluid. This dispersion relation is a consequence of a peculiar infinite symmetry group that emerges at large angular velocity and implies an infinite ground-state degeneracy. The degeneracy is lifted by small corrections which we determine for general equations of state and trapping potentials.

Due to their strong anisotropic and quasi-one-dimensional (1D) nature, transition metal trichalcogenides (TMTCs) $M{X}_3$ exhibit extraordinary electronic properties, such as charge density waves, superconducting transitions, and potentially a Luttinger liquid state. Rich quantum phenomena emerge under pressure, owing to enhanced interchain interactions, and exhibit strong dependencies on the elements $M$ and $X$. In this paper, we investigate structural phase transitions and the insulator-to-superconductor transition in highly insulating ${\mathrm{ZrS}}_3$ under pressures up to 119 GPa. A first-order isosymmetric transition occurs above 16 GPa, companying by a sudden reduction in the band gap due to the breaking of S-S bonds within the 1D chains and the formation of S-S bonds between chains. Superconducting behavior is observed starting at 63 GPa, with $T_c$ increasing under pressure and reaching 9.1 K at 119 GPa. Our findings provide insights into the high-pressure electronic properties of insulating ${\mathrm{ZrS}}_3$ and stimulate further exploration of emergent phenomena in other low-dimensional material systems.

Recently it was demonstrated that the temperature dependence of the quasiparticle weight $Z$ in metals with local self-energy is experimentally measurable [A. Hunter et al., Phys. Rev. Lett. 131, 236502 (2023)]. Motivated by this finding, we study the quasiparticle properties of metals with phenomenological electron-electron interaction described by the Eliashberg function ${\alpha }^{2}F\left(y\right)$ scaling as $y^{\beta }$ in the limit of low energies $y$. We show that the temperature dependence of $Z$ is nonuniversal and strongly depends, inter alia, on the value of the exponent $\beta$. The validity of the recently introduced “power-law liquid ansatz” for the frequency and temperature dependence of the quasiparticle lifetime is studied within the same model as well.

In the presence of quenched disorder, the interplay between local magnetic-moment formation and Anderson localization for electrons at a zero-temperature, metal-insulator transition (MIT) remains a long unresolved problem. Here, we study the emergence of these phenomena in a power-law random banded matrix model of spin-1/2 fermions with repulsive Hubbard interactions. Focusing on the regime of weak interactions, we perform both analytical field theory and numerical self-consistent Hartree-Fock calculations. We show that interference-mediated effects strongly enhance the density of states and magnetic fluctuations upon approaching the MIT from the metallic side. These are consistent with results due to Finkel'stein obtained four decades ago. Our numerics further show that local moments nucleate from typical states as we cross the MIT, with a density that grows continuously into the insulating phase. We identify spin-glass order in the insulator by computing the overlap distribution between converged Hartree-Fock mean-field moment profiles. Our results indicate that itinerant interference effects can morph smoothly into moment formation and magnetic frustration within a single model, revealing a common origin for these disparate phenomena.

Negative magnetization phenomenon is an unusual magnetic behavior where magnetic ordering temperature of two or more types of constituent magnetic moments are believed to be different. This magnetization crossover from positive to negative at low temperatures has triggered interest due to its futuristic potential applications in spintronics. In the present article, our experimental and theoretical results manifest the magnetization reversal in nanocrystalline ${\mathrm{Gd}}_{0.5}{\mathrm{Sr}}_{0.5}{\mathrm{MnO}}_3$ compounds, while this intrinsic effect of negative magnetization is absent in the bulk form. We argue that the antiferromagnetic interactions between Gd sublattice and Mn sublattices increases with decreasing particle size of the ${\mathrm{Gd}}_{0.5}{\mathrm{Sr}}_{0.5}{\mathrm{MnO}}_3$ compound as we go from bulk to nanocrystalline compounds and hence exhibits the negative magnetization in nanocrystalline compounds at low temperatures. We implement Monte Carlo simulation based on classical Heisenberg model supplemented by magnetocrystalline anisotropy to emphasize the key role of this antiferromagnetic interaction among Gd and Mn sublattices by systematically studying negative magnetization.

We study the dynamics of two capacitively coupled quantum dots, each coupled to a lead. A Floquet Green's function approach described the system's dynamics, with the electron-electron interactions handled with the fluctuation-exchange approximation. While electrons cannot move between the separate sections of the device, energy transfer occurs with the periodic driving of one of the leads. This process was found to be explained with four stages. The energy transfer was also found to be sensitive to the driving frequency of the leads. An optimal frequency, resulting in a maximum time-averaged energy current through the system, was identified and explained with the completion of a four-stage process.

One of the proposed ground states of monolayer ${\mathrm{WTe}}_2$, a two-dimensional topological insulator, is an excitonic condensate. However, time-reversal preserving and breaking solutions are competing at the mean-field level of analysis, and it is unclear which condensate, if any, is realized in nature. In this work we analyze the experimental signatures that allow to provide evidence for the excitonic ground states and to distinguish between the two types of condensates using scanning tunneling microscopy. We provide clear experimental signatures in local mapping and quasiparticle interference patterns that visualize the expected changes in local charge and spin density, and characterize allowed backscattering processes in the presence of impurities and disorder. Our results will thus help in the determination of the nature of the ${\mathrm{WTe}}_2$ ground state.

Non-Hermitian skin effect (NHSE), characterized by a majority of eigenstates localized at open boundaries, is one of the most iconic phenomena in non-Hermitian lattice systems. Despite notable experimental studies, most of them witness only certain signs of the NHSE rather than the intrinsic exponential localization inherent in eigenstates, owing to the ubiquitous background loss. Here, we propose a dual-test approach to eliminate the undesired loss effect and track the intrinsic NHSEs that are irrelevant to background loss. The approach is then experimentally validated in non-Hermitian acoustic lattices, which are skillfully constructed by coordinating passive air cavity-tube structures and active unidirectional couplers. Apart from observing the pure NHSE in the prototypical Hatano-Nelson lattice, we precisely capture the intrinsic characteristics of defect-related NHSE, symmetry-enriched NHSE, and high-dimensional interface NHSE. Our study provides conclusive experimental evidence for the fundamental NHSEs in lossy lattices, and showcases the applicability and robustness of our approach across different lattice structures and random perturbations.

Magnetic quantum oscillations (MQO) provide a common tool to probe the electronic structure of various conductors. The Fermi surface of most metals is now known due to the MQO. This tool is more precise than its alternatives, but requires low temperatures, clean samples and rather strong magnetic fields. In this paper the MQO of Hall coefficient are measured in rare-earth tritelluride ${\mathrm{TmTe}}_3$ and shown to be much stronger and persist to higher temperature than the Shubnikov-de Haas oscillations. This amplitude enhancement simplifies the MQO experiments and is very general in strongly anisotropic metals. The combined measurements of Hall and diagonal magnetoresistance provide additional useful information. The ratio of their MQO amplitudes depends linearly on magnetic field, and its slope gives a simple and accurate measurement tool of the electron mean free time and its temperature dependence, unachievable from the usual Dingle plot. Our results expand the use and applications of MQO as a powerful tool to investigate the electronic structure.

In β-Zr alloys, the mechanism of ω phase formation and its interaction with deformation twinning remain subjects of debate, particularly under high strain-rate loading. In this paper, we investigate the β → ω phase transformation in shock loaded Zr-10Nb (at. %) single crystals using molecular dynamic simulations. Our findings indicate a direct connection between deformation-induced phase transformation and the spatial arrangement of Nb atoms. The initiation of both the ω phase and ${\left\{112\right\}}_{\beta }$ ${\langle 111\rangle }_{\beta }$ deformation twins is mediated by the formation of $\frac{1}{6}$ ${\langle 111\rangle }_{\beta }$ partial dislocations (PDs). It is the local Nb composition that dictates the more energetically favorable transition path toward the subsequent formation of the ω phase or deformation twins. Remarkably, we identify a previously unknown mechanism for the β → ω transformation. This process begins with the emergence of $\frac{1}{6}$ ${\langle 111\rangle }_{\beta }$ partials, separated by a few atom layers, followed by atomic shuffling between the PDs. Our findings outline the importance of compositional fluctuation in the transformation mediated plasticity in metastable Zr-based alloys.