Using a procedure based on interpolation via continued fractions supplemented by statistical sampling, we analyze proton magnetic form factor data obtained via electron+proton scattering on $Q^2 \in [0.027,0.55]$ GeV$^2$ with the goal of determining the proton magnetic radius. The approach avoids assumptions about the function form used for data interpolation and ensuing extrapolation onto $Q^2\simeq 0$ for extraction of the form factor slope. In this way, we find $r_{\scriptscriptstyle {\rm M}} = 0.817(27)$ fm. Regarding the difference between proton electric and magnetic radii calculated in this way, extant data are seen to be compatible with the possibility that the slopes of the proton Dirac and Pauli form factors, $F_{1,2}(Q^2)$, are not truly independent observables; to wit, the difference $F_1^\prime(0)-F_2^\prime(0)/\kappa_{\rm p} = [1+\kappa_{\rm p}]/[4 m_{\rm p}^2]$, viz., the proton Foldy term.

A Stark decelerator can slow down polar molecules to very low velocities. When the velocities are very low, the number of cold molecules obtained is very small. In order to obtain a higher quantity of cold molecules, inspired by the work of Reens et al. [Phys. Rev. Res. 2 (2020) 033095], we propose an alternative method of operating a Stark decelerator. Through the trajectory simulation of OH molecules in the decelerator, we find that the number of cold molecules can be greatly increased by one order of magnitude at both low and high final velocities on a Stark decelerator consisting of around 150 electrodes. This development is due to the improved longitudinal and the transverse focusing property provided by the new switching schemes and the high-voltage configurations on the decelerator unit.

We propose a method to retrieve the angle-dependent strong-field ionization of highest occupied molecular orbital (HOMO) from high-order harmonic generation (HHG) of aligned molecules. This method is based on the single-molecule quantitative rescattering model with known alignment distribution and photo-recombination cross sections of fixed-in-space molecules. With the macroscopic HHG of aligned N$_{2}$ molecules, we show that angle-dependent ionization of HOMO can be successfully retrieved at both low and high degrees of alignment. We then show that the error in the retrieved angular dependence of ionization becomes larger if the uncertainty in the alignment distribution is introduced in the retrieval procedure. We also examine that the retrieved ionization of HOMO is much deviated from the accurate one if the intensity of probe laser becomes higher such that inner HOMO-1 can contribute to HHG.

Taking heat positively as the information carrier, thermotronics can exempt the long-lasting thermal issue of electronics fundamentally, yet has been faced with the challenging multiplexing integration of diverse functionalities. Here, we demonstrate a spatiotemporal modulation platform to achieve multiplexing thermotronics functionalities based on the thermal-hysteresis vanadium dioxide, including negative-differential thermal emission, thermal diode, thermal memristor, thermal transistor, and beyond. The physics behind the multiplexing thermotronics lies in the thermal hysteresis emission characteristics of the phase-changing vanadium dioxide during the spatiotemporal modulation. The present spatiotemporal modulation is expected to stimulate more exploration on novel functionalities, system integration, and practical applications of thermotronics.

Room-temperature thermoelectric materials are important for converting heat into electrical energy. As a wide-bandgap semiconductor material, CuI has the characteristics of non-toxicity, low cost, and environmental friendliness. In this work, CuI powder was synthesized by a wet chemical method, then CuI film was formed by vacuum assisted filtration of the CuI powder on a porous nylon membrane, followed by hot pressing. The film exhibits a large Seebeck coefficient of 600 µV$\cdot$K$^{-1}$ at room temperature. In addition, the film also shows good flexibility ($\sim $95% retention of the electrical conductivity after being bent along a rod with a radius of 4 mm for 1000 times). A finger touch test on a single-leg TE module indicates that a voltage of 0.9 mV was immediately generated within 0.5 s from a temperature difference of 4 K between a finger and the environment, suggesting the potential application in wearable thermal sensors.

Lithium deposition on graphite electrode not only reduces fast-charging capability of lithium ion batteries but also causes safety trouble. Here, a low-field $^{7}$Li dynamic nuclear polarization (DNP) is used to probe Li plating on the surfaces of three types of carbon electrodes: hard carbon, soft carbon and graphite. Owing to the strong Fermi contact interaction between $^{7}$Li and conduction electrons, the $^{7}$Li nuclear-magnetic-resonance (NMR) signal of Li metal deposited on electrode surface could be selectively enhanced by DNP. It is suggested that low-field $^{7}$Li DNP spectroscopy is a sensitive tool for investigating Li deposition on electrodes during charging/discharging processes.

In recent years, great success has been achieved on the classification of symmetry-protected topological (SPT) phases for interacting fermion systems by using generalized cohomology theory. However, the explicit calculation of generalized cohomology theory is extremely hard due to the difficulty of computing obstruction functions. Based on the physical picture of topological invariants and mathematical techniques in homotopy algebra, we develop an algorithm to resolve this hard problem. It is well known that cochains in the cohomology of the symmetry group, which are used to enumerate the SPT phases, can be expressed equivalently in different linear bases, known as the resolutions. By expressing the cochains in a reduced resolution containing much fewer basis than the choice commonly used in previous studies, the computational cost is drastically reduced. In particular, it reduces the computational cost for infinite discrete symmetry groups, like the wallpaper groups and space groups, from infinity to finity. As examples, we compute the classification of two-dimensional interacting fermionic SPT phases, for all 17 wallpaper symmetry groups.

We report the structure and physical properties of two newly discovered compounds AV$_{8}$Sb$_{12}$ and AV$_{6}$Sb$_{6}$ (A = Cs, Rb), which have $C_{2}$ (space group: $Cmmm$) and $C_{3}$ (space group: $R\bar{3}m$) symmetry, respectively. The basic V-kagome unit appears in both compounds, but stacking differently. A V$_{2}$Sb$_{2}$ layer is sandwiched between two V$_{3}$Sb$_{5}$ layers in AV$_{8}$Sb$_{12}$, altering the V-kagome lattice and lowering the symmetry of kagome layer from hexagonal to orthorhombic. In AV$_{6}$Sb$_{6}$, the building block is a more complex slab made up of two half-V$_{3}$Sb$_{5}$ layers that are intercalated by Cs cations along the $c$-axis. Transport property measurements demonstrate that both compounds are nonmagnetic metals, with carrier concentrations at around $10^{21}$ cm$^{-3}$. No superconductivity has been observed in CsV$_{8}$Sb$_{12}$ above 0.3 K under in situ pressure up to 46 GPa. Compared to CsV$_{3}$Sb$_{5}$, theoretical calculations and angle-resolved photoemission spectroscopy reveal a quasi-two-dimensional electronic structure in CsV$_{8}$Sb$_{12}$ with $C_{2}$ symmetry and no van Hove singularities near the Fermi level. Our findings will stimulate more research into V-based kagome quantum materials.

It is known that p-type GeTe-based materials show excellent thermoelectric performance due to the favorable electronic band structure. However, n-type doping in GeTe is of challenge owing to the native Ge vacancies and high hole concentration of about $10^{21}$ cm$^{-3}$. In the present work, the formation energy of cation vacancies of GeTe is increased through alloying PbSe, and further Bi-doping enables the change of carrier conduction from p-type to n-type. As a result, the n-type thermoelectric performance is obtained in GeTe-based materials. A peak $zT$ of 0.34 at 525 K is obtained for (Ge$_{0.6}$Pb$_{0.4})_{0.88}$Bi$_{0.12}$Te$_{0.6}$Se$_{0.4}$. These results highlight the realization of n-type doping in GeTe and pave the way for further optimization of the thermoelectric performance of n-type GeTe.

We study electrical modulation of transport properties of silicene nanoconstrictions with different geometrical structures. We investigate the effects of the position and width of the central scattering region on the conductance with increasing Fermi energy. It is found that the conductance significantly depends on the position and the width of the nanoconstriction. Interestingly, the symmetrical structure of the central constriction region can induce a resonance effect and significantly increase the system's conductance. We also propose a novel two-channel structure with an excellent performance on the conductance compared to the one-channel structure with the same total width. Such geometrically-induced conductance modulation of silicene nanostructures can be achieved in practice via current nanofabrication technology.

We report two new members of V-based kagome metals CsV$_{6}$Sb$_{6}$ and CsV$_{8}$Sb$_{12}$. The most striking structural feature of CsV$_{6}$Sb$_{6}$ is the V kagome bilayers. For CsV$_{8}$Sb$_{12}$, there is an intergrowth of two-dimensional V kagome layers and one-dimensional V chains, and the latter ones lead to the orthorhombic symmetry of this material. Further measurements indicate that these two materials exhibit metallic and Pauli paramagnetic behaviors. More importantly, different from CsV$_{3}$Sb$_{5}$, the charge density wave state and superconductivity do not emerge in CsV$_{6}$Sb$_{6}$ and CsV$_{8}$Sb$_{12}$ when temperature is above 2 K. Small magnetoresistance with saturation behavior and linear field dependence of Hall resistivity at high field and low temperature suggest that the carriers in both materials should be uncompensated with much different concentrations. The discovery of these two new V-based kagome metals sheds light on the exploration of correlated topological materials based on kagome lattice.

We report the synthesis and superconducting properties of a layered cage compound Ba$_{3}$Rh$_{4}$Ge$_{16}$. Similar to Ba$_{3}$Ir$_{4}$Ge$_{16}$, the compound is composed of 2D networks of cage units, formed by noncubic Rh–Ge building blocks, in marked contrast to the reported rattling compounds. The electrical resistivity, magnetization, specific heat capacity, and μSR measurements unveiled moderately coupled s-wave superconductivity with a critical temperature $T_{\rm c}=7.0$ K, the upper critical field $\mu_{0}H_{\rm c2}(0) \sim 2.5$ T, the electron-phonon coupling strength $\lambda_{\rm e-ph} \sim 0.80$, and the Ginzburg–Landau parameter $\kappa \sim 7.89$. The mass reduction with the substitution of Ir by Rh is believed to be responsible for the enhancement of $T_{\rm c}$ and coupling between the cage and guest atoms. Our results highlight the importance of atomic weight of framework in cage compounds in controlling the $\lambda_{\rm e-ph}$ strength and $T_{\rm c}$.

Fast in situ switching of magnetic vortex core in a ferromagnetic nanodisk assisted by a nanocavity, with diameter comparable to the dimension of a vortex core, is systematically investigated by changing the strength as well as the diameter of the effective circular region of the applied magnetic field. By applying a local magnetic field within a small area at the nanodisk center, fast switching time of about 35 ps is achieved with relatively low field strength (70 mT) which is beneficial for fast data reading and writing. The reason for this phenomenon is that the magnetic spins around the nanocavity is aligned along the cavity wall due to the shape anisotropy when the perpendicular field is applied, which deepens the dip around the vortex core, and thus facilitates the vortex core switching.

Detection of ultralow magnetic field requires magnetic sensors with high sensitivity and low noise level, especially for low operating frequency applications. We investigated the transport properties of tunnel magnetoresistance (TMR) sensors based on the double indirect exchange coupling effect. The TMR ratio of about 150% was obtained in the magnetic tunnel junctions and linear response to an in-plane magnetic field was successfully achieved. A high sensitivity of 1.85%/Oe was achieved due to a designed soft pinned sensing layer of CoFeB/NiFe/Ru/IrMn. Furthermore, the voltage output sensitivity and the noise level of 10.7 mV/V/Oe, 10 nT/Hz$^{1/2}$ at 1 Hz and 3.3 nT/Hz$^{1/2}$ at 10 Hz were achieved in Full Wheatstone Bridge configuration. This kind of magnetic sensors can be used in the field of smart grid for current detection and sensing.

Topological edge flow and dissipationless odd viscosity are two remarkable features of chiral active fluids composed of active spinners. These features can significantly influence the dynamics of suspended passive particles and the interactions between the particles. By computer simulations, we investigate the transport phenomenon of anisotropic passive objects and the self-assembly behavior of passive spherical particles in the active spinner fluid. It is found that in confined systems, nonspherical passive objects can stably cling to boundary walls and are unidirectionally and robustly transported by edge flow of spinners. Furthermore, in an unconfined system, passive spherical particles are able to form stable clusters that spontaneously and unidirectionally rotate as a whole. In these phenomena, strong particle-wall and interparticle effective attractions play a vital role, which originate from spinner-mediated depletion-like interactions and can be largely enhanced by odd viscosity of spinner fluids. Our results thus provide new insight into the robust transport of cargoes and the nonequilibrium self-assembly of passive intruders.