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Anomalous conducting behavior of solids may reflect the presence of novel quantum states. Here, Zhang et al. report an increased conductivity in TaAs with a magnetic field applied along the direction of the current, which reveals an inherent property of the Weyl Fermion.

The authors study the non-centrosymmetric achiral material In_xTaS₂ by angle-resolved photoemission spectroscopy and quantum oscillations. They find that it hosts an “ideal” Kramers nodal line, well isolated at the Fermi level.

It has been predicted that elemental Iron, with low dimensionality, will be a topological metal hosting Weyl nodes. Here, Chen et al. grow iron on tungsten, a heavy metal with a strong spin-orbit interaction, and using momentum microscopy, show the emergence of giant open Fermi arcs which can be shaped by varying the magnetization of the iron.

The nonlinear Hall effect is observed in bilayer WTe₂ in the absence of a magnetic field, providing a direct measure of the dipole moment of the Berry curvature.

Research on sustainable diets has primarily focused on human and planetary health, neglecting workers in food value chains. This study quantifies the risk of forced labour embedded in five different diets in the USA, underscoring the need to integrate such risk in sustainable diet transition efforts.

The search for magnetic Weyl fermion remains a challenge. Here, the authors report angle-resolved photoemission spectroscopy and magnetotransport measurements resolving the topological properties of Weyl fermion quasiparticles in magnetic non-centrosymmetric crystal PrAlGe.

An analysis of T cell responses in people with amyotrophic lateral sclerosis shows that the C9orf72 antigen is a key target of autoimmune responses in the disease, and identifies C9orf72 epitopes that are recognized.

Optical spin–orbit coupling is known to occur in open systems such as helical waveguides. Here, the authors enable spin–orbit coupling of light confined to a closed path within an asymmetric optical microcavity and demonstrate a non-cyclic Berry phase acquired in a non-Abelian evolution.

The antiferromagnet CoNb₃S₆ with chiral crystal lattice has near-zero magnetization, but exhibits a large thermoelectric Nernst effect in zero magnetic field, attributed to topological nodal planes in its electronic structure and magnetic spin-space group symmetries in the ordered state.

A new class of moiré materials based on monolayers with triangular lattices and low-energy states at the M points of the Brillouin zone is introduced, demonstrating emergent momentum-space non-symmorphic symmetries, a kagome plane-wave lattice structure, and potential quasi-one-dimensionality.

The interaction of terahertz (THz) waves with condensed matter materials is utilised to investigate the low-energy electronic behaviours and topological properties near the equilibrium state, for example, transport characteristics of topological semimetals. Here, the THz longitudinal conductivities of high-quality Mn₃Sn epitaxial thin films are anisotropic along different crystal orientations with carrier localization behavior, which are well described by the Drude-Smith model.

The symmetry and mechanism underlying unconventional charge orders in Kagome materials are under debate. Here, the authors uncover a longitudinal and helicity-dependent photocurrent in KV₃Sb₅ that indicates broken symmetries and intrinsic chirality.

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.

Measurements on a chiral magnet show that non-symmorphic symmetries enforce topological crossings exactly at the Fermi level in certain materials; these crossings can be controlled by an applied magnetic field.

Previous work has proposed that the anomalous and topological Hall effects, associated with Weyl nodes, should have a signature in optical conductivity. Here, using THz optical spectroscopy, the authors assign these two effects to optical conductivity resonances, arising near band anti-crossings, in thin films of MnGe.

Kekulé vortices in hexagonal lattices can host fractionalized charges at zero magnetic field, but have remained out of experimental reach. Here, the authors report a Kekulé vortex in the local density states of graphene around a chemisorbed hydrogen adatom.

Using torque magnetometry, the thermodynamic signatures of bosonic Landau level transitions are observed in a layered superconductor, owing to the formation of Cooper pairs with finite momentum.

Sr_1−yMn_1−zSb₂ (y, z < 0.1) is reported to be a magnetic topological semimetal exhibiting nearly massless relativistic fermions.

The spin and valley degrees of freedom are coupled in two-dimensional transition-metal dichalcogenides. Here, the authors use high magnetic fields to optically measure the valley Zeeman effect and diamagnetic exciton shift in tungsten disulphide and molybdenum disulphide, and determine the exciton binding energies.

The nonlinear Hall effect is a quantum phenomenon, in which two perpendicular currents induce a Hall voltage; however, previous theories for this effect has remained at the semi classical level. Here, the authors develop a full quantum theory of the nonlinear Hall effect by using the diagrammatic technique.

High-harmonic generation from the Dirac-like surface state of a topological insulator is separated from bulk contributions and continuously tuned by the carrier-envelope phase of the driving lightwave.

The transport behavior of the carriers residing in the lowest Landau level is hard to observe in most topological materials. Here, Liu et al. report a surprising angular dependence of the interlayer magnetoresistivity and Hall conductivity arising from the lowest Landau level under high magnetic field in type II Weyl semimetal YbMnBi₂.

Responses to high-intensity mid-infrared laser light are theoretically investigated in the Haldane system. It is found that the primary electronic response, optical tunnelling and high-harmonic emission are sensitive to the topological phase of matter.

Individuals with symptoms of anxiety and depression exhibit persistent underconfidence. Here, the authors show that distortions in learning from local metacognition can explain how underconfidence is maintained in the face of intact performance.

Spectroscopic signatures of magnetic response in topological materials remain very limited. Here, the authors observe a quasi-linear field dependent transverse magnetization and a non-saturating parallel magnetization in a Weyl semimetal TaAs under strong magnetic field, suggesting a signature of relativistic quasiparticles in topological materials.

Proposals for the realization of Weyl semimetals, topologically non-trivial materials which host Weyl fermion quasiparticles, have faced demanding experimental requirements. Here, the authors predict such a state in stoichiometric TaAs, arising due to the breaking of inversion symmetry.

While topological states are often characterized by their global properties related to the topological invariants, the introduced real-space topological markers provide new insights to these states.

Thouless introduced the idea of a topological charge pump: the quantized motion of charge due to the slow cyclic variation of a periodic potential. This topologically protected transport has now been realized with ultracold bosonic atoms.

The quark structure of the f₀(980) hadron is still unknown after 50 years of its discovery. Here, the CMS Collaboration reports a measurement of the elliptic flow of the f₀(980) state in proton-lead collisions at a nucleon-nucleon centre-of-mass energy of 8.16 TeV, providing strong evidence that the state is an ordinary meson.

Above band-gap photovoltage could be achieved in materials with a net polarization. Here, Cooket al. compute the contribution to the shift current from the band edge and identify two classes of shift current photovoltaics materials, GeS and ferroelectric polymer films.

This study explores reentrant topological behaviors in a 1D system of interacting fermionic atoms trapped in an optical lattice obtained by overlapping two commensurable superlattices. It reveals a series of trivial-topological transitions and a spin-density wave pattern influenced by the lattice’s structure and atomic interactions, which could be observed in cold-atom experiments in future experimental setups.

Superlattices, with a length scale and structure that differs from the parent lattice of the host material, are well-known to allow for remarkable new electronic and magnetic properties. Here, Xie et al. synthesize Cr_1/4TaS₂, and find that it exhibits an unusual anomalous Hall effect below the Néel temperature even in stoichiometric high-quality crystals.

The classification of magnets now includes altermagnets which possess opposite-spin sublattices connected by rotation and share some features with ferro- and antiferromagnets. Here the authors report the anomalous Hall effect in Mn5Si3 and interpret the results in terms of a d-wave altermagnetic phase.

Charge-to-spin conversion, where a charge current generates a spin-current, is critical for spintronic devices. Usually efficient charge-to-spin conversion relies on heavy metals with large spin-orbit interactions, but here, Chakraborty et al show that high efficiency charge-to-spin conversion can be achieved without spin-orbit coupling using recently identified p-wave magnets.

A spatially dispersive photoresponse is found in a topological semimetal.

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.

Disorder may play a dominant role in determining the nonlinear Hall effect in a topological material. Here, Du et al. derive formulas of the nonlinear Hall conductivity and construct the general scaling law of the nonlinear Hall effect in a tilted two dimensional Dirac model.