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Recent work has expanded the concept of altermagnets to non-collinear magnetic materials. Here, Hu et al extend this further to non-collinear chiral materials, determining altermagnetic multipolar order parameters and predicting that such materials host large spin-hall and Edelstein effects.

Previous models explain solid-solution strengthening by differences in atomic volume and electronegativity of the constituent atoms. Here, the authors consider both factors simultaneously and identify atomic volume as the dominant factor for FCC alloys.

Three-dimensional topological insulators are materials that are nonmagnetic insulators in the bulk but exhibit metallic surface states. Yoshimi et al, now identify a signature of such two-dimensional states, the quantum Hall effect, in bismuth-based chalcogenide topological insulators.

The electronic ground state of a correlated oxide interface is reversibly switched by light. Stemming from interfacial reconstructions, electrostatic confinement and photodoping, this effect opens a path towards engineering the optical response of oxides.

The topological Hall effect usually results from a static scalar spin chirality. Here, through a combination of neutron scattering and transport measurements, Baral et al. demonstrate the emergence of a room temperature topological Hall effect due to dynamic scalar spin chirality in a topologically non-trivial phase in Fe3Ga4

Skyrmions, when driven by any applied force, experience an addition sideways motion known as the skyrmion hall effect. Here, Brearton et al. present a reciprocal space method for determining the strength of the skyrmion hall effect, making measurement possible for skyrmion lattices.

Electronic systems with inverted band structures can support exotic topological insulator and exciton condensate states. Here, the authors demonstrate the formation of a helical exciton condensate in quantum Hall bilayers, and a quark-like quasiparticle confinement-deconfinement transition.

Communication between room-temperature and cryogenic environments is a bottleneck to the scaling of cryogenic devices. Here, the authors introduce a technique for in situ writing and erasing of circuits at low temperatures, enabling reversible construction of patterns without a photoresist.

Integrating mirrors with magnetic components is crucial for constructing chiral optical cavities, which provide tunable platforms for time-reversal-asymmetric light-matter interactions. Here, the authors introduce single-crystal circular-polarization-selective mirrors based on chiral superconductors, which break time-reversal symmetry themselves, eliminating the need for additional components.

Magnetization reversal in magnetic topological insulators drives quantum phase transitions between quantum anomalous Hall, axion insulator, and normal insulator states. Using novel analysis protocol, the authors investigate critical behaviours of these transitions and establish their electronic origin.

Graphene on boron nitride gives rise to a moiré superlattice displaying the Hofstadter butterfly: a fractal dependence of energy bands on external magnetic fields. Now, by means of capacitance spectroscopy, further aspects of this system are revealed—most notably, suppression of quantum Hall antiferromagnetism at particular commensurate magnetic fluxes.

The anomalous Hall effect is a macroscopic manifestation of a quantum mechanical effect. Here, Uelandet al. report the observation of a high Hall conductivity in the heavy-fermion compound UCu5, a metallic system, and explain its origin in terms of geometric frustration effects.

Conduction in ferroelectric domain walls is now an established phenomenon, yet fundamental aspects of transport physics remain elusive. Here, Campbellet al. report the type, density and mobility of carriers in conducting domain walls in ytterbium manganite using nanoscale Hall effect measurements.

Future information storage technology may exploit electrical currents to write the states of ferromagnetic nanoelements via spin torque effects. Here, the authors demonstrate such behaviour promoted by exchange bias from an interfaced antiferromagnet, which may help overcome practical device limitations.

Non-local transport measurements on mercury telluride quantum wells show clear signatures of the ballistic spin Hall effect. The ballistic nature of the experiment allows the observed effect to be interpreted as a direct consequence of the band structure of these semiconductor nanostructures, rather that being caused by impurity scattering.

A technique that allows the electrical detection of spin-polarized transport in semiconductors without disturbing the spin-polarized current or using magnetic elements has now been demonstrated. The approach could lead to the integration of spintronics elements into semiconductor microelectronic circuits.

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 relationship between the integer and fractional quantum Hall states are of fundamental importance in condensed matter physics. Here, the authors report a universality of phase transitions in both regimes in ultraclean trilayer graphene samples.

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 effect of disorder in conventional two-dimensional electron systems is usually described in terms of individual electrons interacting with an underlying disorder potential. Scanning single-electron transistor measurements of graphene in a strong magnetic field indicate that in this system, coulombic interactions between electrons must also be taken into account.

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.

Energy relaxation crucially impacts transport properties of mesoscopic devices. Here the authors show that energy can be distributed between distant parts of the sample, which may provide a resolution to an outstanding puzzle concerning energy conservation in transport through quantum Hall edges.

A unified realization of the volt, ohm and ampere can be achieved by integrating a quantum anomalous Hall resistor and a programmable Josephson voltage standard in a single cryostat.

A 3D quantum Hall effect has been reported in Dirac semimetal ZrTe₅ due to a magnetic-field-driven Fermi surface instability. Here, the authors show evidence of quasi-quantized Hall response without Fermi surface instability, but they argue that it is due to the interplay of the intrinsic properties of ZrTe₅ electronic structure and Dirac semi-metallic character.

Magnetic imaging reveals that a transport current flows in the interior of Cr-(Bi,Sb)₂Te₃ samples within the quantum anomalous Hall regime, contrary to the common assumption of current flow along the sample edge.

Quantum Hall interferometers have proven to be a useful platform for the study of fractional statistics. Here, the authors experimentally study the effect of Coulomb interactions between bulk and edge charges on the interferometer behavior, validating previous theoretical predictions.

Electron hopping in geometrically frustrated lattices can result in a rich variety of unusual behaviours. Now, the orbital arrangement in a van der Waals metal with a non-frustrated, primitive lattice is found to show similar effects.

Three tunable quantum Hall broken-symmetry states in charge-neutral graphene are identified by visualizing their lattice-scale order with scanning tunnelling microscopy and spectroscopy.

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.

There is a long-standing experimental effort to observe field-induced correlated states in three-dimensional materials. Here, the authors observe an unconventional Hall response in the quantum limit of the bulk semimetal HfTe₅ with a plateau-like feature in the Hall conductivity.

The evolution of the quantum Hall state from bulk spectrum to edge state remains obscure. Here, Patlatiuk and Scheller et al. observe magnetic compression against a hard edge followed by motion into the bulk and depopulation of the integer quantum Hall edge states, in agreement with the bulk-to-edge correspondence.

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.

In quantum anomalous Hall (QAH) materials, the mesoscopic scattering length (L_s) plays an instrumental role in determining transport properties. Here, the authors examine L_s in three regimes (QAH, quantum critical, and insulating) with distinct transport behaviours, and find a universal L_s across all regimes.

The Weyl semimetal Co\(_{3}\)Sn\(_{2}\)S\(_{2}\) exhibits a combination of magnetic ordering with a large anomalous Hall effect. Lachman et al. find an intrinsic exchange bias of this anomalous Hall effect and attribute it to the coexistence of ferromagnetism and spin glass behaviour.

Planning for the Colorado River is critical to secure water and hydropower for the western US under climate change. This study highlights how different policies may reduce but not eliminate the risk of losing water and energy supply altogether.

An interferometer device demonstrates the interference of fractional quantum Hall effect edge states. This is a big step towards braiding non-Abelian anyons.

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.

Improved generation and manipulation of pure polariton spin transport over distances of tens of micrometres is a step towards spintronic applications.

Direct measurement of the Berry curvature and the quantum metric of photonic modes in a high-finesse planar microcavity is achieved, enabling quantitative prediction of the independently measured anomalous Hall drift.

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.

Experiments show that when driven by electric currents, magnetic skyrmions experience transverse motion due to their topological charge — similar to the conventional Hall effect experienced by charged particles in a perpendicular magnetic field.

The performance of inverted perovskite solar cells has been limited by non-radiative recombination at the perovskite surfaces. Here, authors employ phosphonic acids and piperazinium chloride for homogeneous passivation, achieving certified efficiency of 28.9% for 60 cm² perovskite-silicon tandems.

The kagome magnet Co₃Sn₂S₂ has complex magnetic behaviour and a topological band structure that yields a large anomalous Hall effect. Guguchia et al. find phase separation between ferro- and anti-ferromagnetic orders and that the volume-wise competition controls the anomalous Hall conductivity

Measuring real time magnetization dynamics resulting from Hall effects is hard due to the small signal size. Here Sala et al demonstrate a method of performing Hall resistance measurements with sub-ns resolution, and use it to investigate the switching of GdFeCo dots induced by spin-orbit torques.

The Hall effect has been used as a probe of the normal state of cuprates, when superconductivity is supressed by a magnetic field. Here, the authors report the vanishing of the Hall coefficient at high magnetic field in cuprates with stripe order and interpret it as a signature of the stripe-ordered phase.

Topologically protected pseudospin transport is difficult to implement for bosonic systems due to the lack of symmetry-protected pseudospins. Here, Bleu et al. propose robust valley pseudospin transport, truly topologically protected by the winding of a quantum vortex propagating between two staggered honeycomb lattices.

A transient topological response in graphene is driven by a short pulse of light. When the Fermi energy is in the predicted band gap the Hall conductance is around two conductance quanta. An ultrafast detection technique enables the measurement.

Charge dynamics in perovskite is not well-understood, limited by the knowledge of defect physics and charge recombination mechanism, yet the ABC and SRH models are widely used. Here, the authors introduce advanced PLQY mapping as function of excitation pulse energy and repetition frequency to examine the validity of these models.