EISSN : 2399-3650
Published by: Springer Nature (10.1038)
Total articles ≅ 671
Latest articles in this journal
Communications Physics, Volume 4, pp 1-9; https://doi.org/10.1038/s42005-021-00702-4
The kinetic magnetoelectric effect is an orbital analog of the Edelstein effect and offers an additional degree of freedom to control magnetization via the charge current. Here we theoretically propose a gigantic kinetic magnetoelectric effect in topological insulators and interpret the results in terms of topological surface currents. We construct a theory of the kinetic magnetoelectric effect for a surface Hamiltonian of a topological insulator, and show that it well describes the results by direct numerical calculation. This kinetic magnetoelectric effect depends on the details of the surface, meaning that it cannot be defined as a bulk quantity. We propose that Chern insulators and Z 2 topological insulators can be a platform with a large kinetic magnetoelectric effect, compared to metals by 5–8 orders of magnitude, because the current flows only along the surface. We demonstrate the presence of said effect in a topological insulator, identifying Cu2ZnSnSe4 as a potential candidate.
Communications Physics, Volume 4, pp 1-7; https://doi.org/10.1038/s42005-021-00716-y
Size is a fundamental quantity of magnetic skyrmions. A magnetic skyrmion can be a local circular object and in an isolated form. A skyrmion can also coexist with a group of its siblings in a condensed phase. Each skyrmion in a condensed phase takes a stripe shape at low skyrmion density and a circular shape at high skyrmion density. Skyrmions at high density form a skyrmion crystal (SkX). So far, skyrmion size in an SkX has not been seriously studied. Here, by using a generic chiral magnetic film, it is found that skyrmion size in an SkX has a different parameter dependence as those for isolated skyrmions and stripes. A size formula and a good spin profile for skyrmions in SkXs are proposed. These findings have important implications in searching for stable smaller skyrmions at the room temperature.
Communications Physics, Volume 4, pp 1-3; https://doi.org/10.1038/s42005-021-00714-0
Global events in the past year has made prescient a long-standing debate on the definition and suitability of impact and novelty as criteria for publication in selective journals. Reflecting on this issue, Prof Andrea Armani and Prof Jerry Lee argue that rigour and reproducibility is, in fact, more crucial. Global events in the past year has made prescient a long-standing debate on the definition and suitability of impact and novelty as criteria for publication in selective journals. Reflecting on this issue, Prof Andrea Armani and Prof Jerry Lee argue that rigour and reproducibility is, in fact, more crucial.
Communications Physics, Volume 4, pp 1-1; https://doi.org/10.1038/s42005-021-00720-2
Communications Physics, Volume 4, pp 1-10; https://doi.org/10.1038/s42005-021-00713-1
The ability to design the electromagnetic properties of materials to achieve any given wave scattering effect is key to many technologies, from communications to cloaking and biological imaging. Currently, common design methods either neglect degrees of freedom or are difficult to interpret. Here, we derive a simple and efficient method for designing wave–shaping materials composed of dipole scatterers, taking into account multiple scattering effects and both magnetic and electric polarizabilities. As an application of our theory, we design aperiodic metasurfaces that re-structure the radiation from a dipole emitter: (i) modifying of the near-field to provide a 4-fold enhancement in power emission; (ii) re-shaping the far-field radiation pattern to exhibit chosen directivity; and (iii) the design of a discrete Luneburg–like lens. Additionally, we develop a clear physical interpretation of the optimised structure, by extracting eigen-polarizabilities of the system, finding that a large eigen-polarizability corresponds to a large collective response of the scatterers.
Communications Physics, Volume 4, pp 1-11; https://doi.org/10.1038/s42005-021-00700-6
All physical oscillators are subject to thermodynamic and quantum perturbations, fundamentally limiting measurement of their resonance frequency. Analyses assuming specific ways of estimating frequency can underestimate the available precision and overlook unconventional measurement regimes. Here we derive a general, estimation-method-independent Cramer Rao lower bound for a linear harmonic oscillator resonance frequency measurement uncertainty, seamlessly accounting for the quantum, thermodynamic and instrumental limitations, including Fisher information from quantum backaction- and thermodynamically driven fluctuations. We provide a universal and practical maximum-likelihood frequency estimator reaching the predicted limits in all regimes, and experimentally validate it on a thermodynamically limited nanomechanical oscillator. Low relative frequency uncertainty is obtained for both very high bandwidth measurements (≈10−5 for τ = 30 μs) and measurements using thermal fluctuations alone (<10−6). Beyond nanomechanics, these results advance frequency-based metrology across physical domains.
Communications Physics, Volume 4, pp 1-9; https://doi.org/10.1038/s42005-021-00708-y
Flocking models with metric and topological interactions are supposed to exhibit distinct features, as for instance the presence and absence of moving polar bands. On the other hand, quenched disorder (spatial heterogeneities) has been shown to dramatically affect large-scale properties of active systems with metric interactions, while the impact of quenched disorder on active systems with metric-free interactions has remained, until now, unexplored. Here, we show that topological flocking models recover several features of metric ones in homogeneous media, when placed in a heterogeneous environment. In particular, we find that order is long-ranged even in the presence of spatial heterogeneities, and that the heterogeneous environment induces an effective density-order coupling facilitating emergence of traveling bands, which are observed in wide regions of parameter space. We argue that such a coupling results from a fluctuation-induced rewiring of the topological interaction network, strongly enhanced by the presence of spatial heterogeneities.
Communications Physics, Volume 4, pp 1-7; https://doi.org/10.1038/s42005-021-00705-1
Thin, high-density layers of dopants in semiconductors, known as δ-layer systems, have recently attracted attention as a platform for exploration of the future quantum and classical computing when patterned in plane with atomic precision. However, there are many aspects of the conductive properties of these systems that are still unknown. Here we present an open-system quantum transport treatment to investigate the local density of electron states and the conductive properties of the δ-layer systems. A successful application of this treatment to phosphorous δ-layer in silicon both explains the origin of recently-observed shallow sub-bands and reproduces the sheet resistance values measured by different experimental groups. Further analysis reveals two main quantum-mechanical effects: 1) the existence of spatially distinct layers of free electrons with different average energies; 2) significant dependence of sheet resistance on the δ-layer thickness for a fixed sheet charge density.
Communications Physics, Volume 4, pp 1-7; https://doi.org/10.1038/s42005-021-00709-x
The interplay of strong Coulomb interactions and of topology is currently under intense scrutiny in various condensed matter and atomic systems. One example of this interplay is the phase competition of fractional quantum Hall states and the Wigner solid in the two-dimensional electron gas. Here we report a Wigner solid at ν = 1.79 and its melting due to fractional correlations occurring at ν = 9/5. This Wigner solid, that we call the reentrant integer quantum Hall Wigner solid, develops in a range of Landau level filling factors that is related by particle-hole symmetry to the so called reentrant Wigner solid. We thus find that the Wigner solid in the GaAs/AlGaAs system straddles the partial filling factor 1/5 not only at the lowest filling factors, but also near ν = 9/5. Our results highlight the particle-hole symmetry as a fundamental symmetry of the extended family of Wigner solids and paint a complex picture of the competition of the Wigner solid with fractional quantum Hall states.
Communications Physics, Volume 4, pp 1-2; https://doi.org/10.1038/s42005-021-00707-z
The Microscience and Microscopy Congress (mmc) is the standout event of the microscopist’s calendar. This July, hundreds of delegates signed into a virtual mmc2021 to see the latest research and advancements in microscopy, spanning both physical and life sciences. The Microscience and Microscopy Congress (mmc) is the standout event of the microscopist’s calendar. This July, hundreds of delegates signed into a virtual mmc2021 to see the latest research and advancements in microscopy, spanning both physical and life sciences.