Search

Unidirectional spin-hall magnetoresistance is a change in the conductivity of ferromagnetic/heavy metal bilayers that is sensitive to the magnetisation of the ferromagnetic layer. This sensitivity makes it a potential candidate for magnetic state readout. Here, Salikhov et al demonstrate ultrafast unidirectional spin hall magnetoresistance driven by terahertz fields

The superconducting proximity effect has not been experimentally demonstrated in a quantum anomalous Hall insulator. Now this effect is observed in the chiral edge state of a ferromagnetic topological insulator.

Phase tuning of propagating spin waves is a crucial step in the development of devices based on magnons, which are the quanta of spin waves. Now, this has been demonstrated in a device comprising two spin Hall nano-oscillators.

Charge-neutral graphene in the quantum Hall regime is known to be an insulator. Now thermal transport measurements show that it also does not conduct heat. This sheds light on the nature of the ground state in this regime.

The authors demonstrate field-free magnetization switching in van der Waals heterostructures.

Orbital angular momentum transfer from optical vortex beams to electronic quantum Hall states is reported in a graphene sheet, showing a robust contribution to the radial photocurrent that depends on the vorticity of light.

Electron pairing is of fundamental interest in condensed matter physics. Here, the authors demonstrate electrons forming not only pairs - but also triplets - in graphene quantum Hall Fabry-Pérot interferometers.

Noncoplanar magnets are promising for spintronics but are rare and challenging to find. Here, the authors provide a chemical design strategy to produce materials with noncoplanar magnetic orders, and strong signatures of their magnetism in the Hall effect.

The optical spin Hall transport of exciton polaritons at room temperature is reported in a perovskite microcavity, which enables them to realize polariton spintronic devices such as a spin-polarized beamsplitter and a polariton spin inverter.

A ketogenic diet in male mice with hyperglycemia normalized blood glucose and enhanced improvements in cardiorespiratory fitness and aerobic remodeling of skeletal muscle with aerobic exercise training, compared to mice consuming regular chow.

Moiré patterns have been experimentally observed in heterostructures comprised of topological insulator films. Here, the authors propose that topological insulator-based moiré heterostructures could be a host of isolated topologically non-trivial moiré minibands for the study of the interplay between topology and correlation.

We show that domain walls in minimally twisted bilayer graphene support exceptionally robust proximity superconductivity in the quantum Hall regime.

Charge-to-spin conversion allows for the generation and control of spin polarization via a charge current. Typically, this is done with non-magnetic materials with large spin-orbit interactions such as Platinum. Herein, Dai et al demonstrate an intriguing charge-to-spin mechanism, a magnetic spin Hall effect, in a van der Waals heterostructure.

This Review describes the concepts behind generalized quantum Hall effects that can take place without a magnetic field, and summarizes recent experimental manifestations of these phenomena in twisted two-dimensional materials and few-layer graphene.

Previous measurements of interferometers based on quantum Hall (QH) edge channels have suggested potential electron pairing effects. Here, the authors investigate the coupling between QH edge channels in graphene Aharonov-Bohm (AB) interferometers, proposing a possible single-particle explanation for the apparent interference phase jumps and AB frequency doubling.

Excitonic pairing in fractional quantum Hall states shows two new quantum phases, including a fractional exciton condensate and an unusual type of exciton that obeys fermionic or anyonic quantum statistics.

Topological states in atomically thin quantum spin Hall insulators suffer from instability against environmental factors. Here, the authors devise a strategy to preserve topologically protected states in monolayer indenene through graphene intercalation.

Hybrid perovskites exhibit long carrier diffusion lengths and lifetimes. Here, Chen et al. show experimentally that carrier recombination in perovskites is far from Langevin and closer to the best direct-bandgap semiconductors, which can be explained by the dipolar polaronic nature of charge carriers.

The orbital Hall effect is observed in the light metal titanium, confirming the orbital Hall effect and indicating that orbital angular momentum is an important degree of freedom in solids.

Ultra-narrow quantum Hall Josephson junctions defined in encapsulated graphene nanoribbons exhibit a chiral supercurrent, visible up to 8  T.

Switching of magnetic behaviour is one of the main ideas that drives spintronics. Now, magnetic switching via spin-orbit torque is shown in a moiré bilayer, introducing a platform for spintronic applications.

The anomalous Hall effect (AHE) occurs in ferromagnets caused by intrinsic and extrinsic mechanisms. Here, Yoo et al. report large anomalous Hall conductivity and Hall angle at the interface between a ferromagnet La_0.7Sr_0.3MnO₃ and a semimetallic SrIrO₃, due to the interplay between correlated physics and topological phenomena.

A new type of Hall effect—the layer Hall effect—is produced in a 2D antiferromagnet that does not exhibit any net magnetization.

Polariton condensation of topological propagating edge states is demonstrated with halide perovskite microcavities.

Recently, anyonic statistics were observed in collision experiments on fractional quantum Hall states. Here the authors report signatures of anyonic statistics in the integer quantum Hall state with two copropagating channels, where electrons are split into fractional charges by inter-channel interaction.

Fermionic currents of opposing chirality can be spatially filtered without the need for a magnetic field using the quantum geometry of topological bands in single-crystal PdGa.

The scaling dimension of fractional quantum Hall anyons shows agreement with expectations following examination of thermal-to-shot-noise crossover measurements by fitting to the predicted finite-temperature expression involving both the scaling dimension of quasiparticles and their charge.

Strongly correlated and topological phases of matter can be often described using the tools of quantum field theory. Here the authors report the thermal Hall effect in the antiferromagnetic skyrmion lattice of MnSc₂S₄, revealing transport features that can be attributed to an emergent SU(3) gauge field.

New functionalities of two-dimensional topological insulators (2DTI) are of current scientific interest. Here, the authors show that topological protection can be lifted by pairwise coupling of 2DTI bismuthene edges in close proximity.

Polycrystalline thin films of elemental bismuth exhibit a room-temperature nonlinear transverse voltage due to geometric effects of surface electrons that is tunable and can be extended to efficient high-harmonic generation at terahertz frequencies.

Similar to optical waves, electrons can also interfere, but they require high-quality devices with minimal scattering for an experimental observation of this effect. An interferometer based on a single sheet of graphene provides an alternative to the more standard semiconductor devices and may in future enable access to exotic quantum effects, such as anyon braiding.

A new platform making use of hexagonal boron nitride interfaced with the molecular superconductor κ-(BEDT-TTF)₂Cu[N(CN)₂]Br is demonstrated for realizing cavity-altered materials, confirmed by magnetic force microscopy and nano-optical measurements.

In most materials, the hall conductivity has a scaling to the longitudinal resistance that varies between linear and quadratic. Here, Zhang et al demonstrate a hall conductivity proportional to the fifth power of the longitudinal conductivity in Mn₃Si₂Te₆, which they attribute to enhanced force on charge carriers due to chiral orbital currents.

Lazarevic et al. reveal a shared loss of a TBX5-dependent atrial gene network in cardiomyocytes and a disease-specific network gain in activated fibroblasts across atrial fibrillation and heart failure models.

The nature of the fractional quantum Hall state when the lowest Landau level is half-filled remains controversial. Now, the observation of a topological phase transition at related filling fractions suggests that the half-filled state is non-Abelian.

Skyrmions - nanoscale, topological spin textures - are promising elements for next-generation computing due to their efficient coupling to currents in racetrack devices. Here, Tan et al. examine over 20,000 instances of current induced skyrmion motion to unveil a comprehensive picture of skyrmion dynamics across currents and fields.

Quantum transport of fractional quasiparticles can drastically differ from conventional charge transport. Here the authors demonstrate Andreev-like reflection of a fractional quasiparticle incident on a barrier in the fractional quantum Hall regime.

Observation of quantum phenomena in correlated electron systems is challenging due to low mobility and high concentration of carriers. Here, Matsubara et al. report a two-dimensional electron system with high mobility-low carrier density in δ-doped SrTiO₃, demonstrating quantum Hall effect in d-electron systems.

Exchange bias occurs in a variety of magnetic materials and heterostructures. The quintessential example occurs in antiferromagnetic/ferromagnetic heterostructures and has been employed extensively in magnetic memory devices. Here, via a specific field training protocol, the authors demonstrate an exchange bias of up to 400mT in odd layered MnBi2Te4.

Magnetoresitance (MR) is a tool to study electronic transport and spin order in metals. Here, the authors demonstrate two different microscopic origins of antisymmetric linear MR from both Zeeman-split Fermi surface and anomalous electron velocity.

A large spin Hall angle and long spin diffusion length are found in the low-symmetry, few-layer semimetal MoTe₂ at room temperature, thus identifying this material as an excellent candidate for simultaneous spin generation, transport and detection.

Interwoven magnetic and non-magnetic layers in TbTi₃Bi₄ overcome kagome frustration, producing coupled elliptical-spiral magnetic and spin-density-wave orders and a very large anomalous Hall effect driven by strong electron–magnetic field interactions.

Excitations of the fractional quantum Hall states are of great interest because they obey anyonic statistics, but electronic interferometers give contrasting results about their quantum coherence. Here the authors use novel two-particle time-domain interferometry to show that quantum coherence is indeed preserved.

Topological insulators are a class of materials with an unusual band structure that makes them metallic at the surface and insulating in the bulk. Okamoto and co-workers use electronic structure calculations to predict a new family of possible topological insulators based on transition-metal oxides.

Previous studies of skyrmions in thin film architectures have shown widely-varying magnitudes of the topological Hall effect. Here, Raju et al. show that this variation follows a power-law behaviour driven by chiral spin fluctuations at the phase transition between isolated and lattice skyrmions.

Skyrmion crystals, where skyrmions are arranged close packed in a triangular lattice arise due to the superposition of three magnetic spin spirals, each with a distinct wave vector, Q. Such skrymion crystals have been found in a diverse array of materials. Here, Park et al find a short wavelength (or dense skyrmion) limit of this skyrmion crystal structure in Co1/3TaS2, a metallic triangular lattice antiferromagnet, in the form of a triple Q magnetic ordering, with four magnetic sublattices.’

A study reports a dual quantum spin Hall insulator in monolayer TaIrTe₄, arising from the interplay of its single-particle topology and density-tuned electron correlations.

The quantum Hall effect in GaAs-based devices defines resistance standards accurate to within one part in 10⁻⁹ at magnetic fields close to 10 T. Here, Lafont et al. demonstrate such accuracies over an extended magnetic field range at 1.4 K in chemically vapour-deposited graphene on silicon carbide.

Recently, it has been shown that Co1/3TaS2 hosts a four-sublattice ‘3Q state’, which has a sizable scalar spin chirality and thus a large anomalous Hall effect. Here, Kim et al demonstrate electrical control of this 3Q state via ionic gating.