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Dirac semimetals have been proposed as parent materials for other topologically non-trivial phases such as Weyl semimetals, achieved by the breaking of time reversal symmetry. Here the authors use transport measurements to evidence such behaviour in single crystal Cd₃As₂under an applied magnetic field.

MnBi₂Te₄ has an appealing combination of topological bands and magnetic ordering. While chemical doping with Sb can be used to tune these properties, it typically comes with an increase in defect density. Here, Chen, Wang, Li, Duan, and coauthors demonstrate a defect engineering approach that preserves the topological and magnetic properties of Mn(Bi_1-xSb_x)₂Te₄.

How the carriers behave in a Weyl semimetal if they occupy the lowest Landau level remains elusive. Here, the authors report evidences of electrons occupying zeroth chiral Landau levels with distinct linear dispersion behaviors for two inequivalent Weyl nodes in a Weyl semimetal NbAs.

A gate voltage has been used to control quantum oscillations in Bi₂Te₃ nanoribbons and enhance the surface conduction.

Cd₃As₂, which is known as a topological Dirac semimetal, has been grown on mica substrates by molecular beam epitaxy with high mobility. The temperature-dependent resistance of as-grown Cd₃As₂ thin films showed semiconducting behavior, indicating the band gap opening as opposed to the bulk counterpart. By solid electrolyte gating, the ambipolar effect and gate-tunable quantum oscillations were clearly demonstrated. These features make the Cd₃As₂ thin film system a promising platform to observe various exotic phenomena and realize new electronic applications.

ZrTe₅ has attracted intensive research interests because of the potential topological property. Here based on the transports and optic experiments, we observe unusual Landau quantization, non-trivial Berry phase and highly anisotropic carrier mass, which reveals quasi-two-dimensional Dirac fermions in bulk ZrTe₅. The system is understood as locating at the critical point between a three-dimensional (3D) Dirac semimetal and a topological insulator. New physics or device application can be possibly realized in this quasi-2D ultra-relativistic system beyond graphene.

The bulk photovoltaic effect holds promise for various optoelectronic applications, but it is usually restricted to non-centrosymmetric materials operating in the visible range. Here, the authors report a surface photogalvanic effect spanning from visible to midinfrared wavelengths in a centrosymmetric topological insulator, Ag₂Te.

Controlling the magnetic properties of a materials system by electric means can lead to efficient electronic and memory devices. Now, for the first time, the control of ferromagnetism by the application of an electric voltage is demonstrated in germanium quantum dots for temperatures up to 100 K.

Mid-infrared pulsed sources are technologically important for sensing and spectroscopy but their implementation is challenging due to the lack of a tuneable optical switch. Here, the authors address this limitation by engineering the band structure of an emerging Dirac semimetal, Cd₃As₂.

Magnetotransport signature of topological semimetal states has been observed but restricted at very low temperature. Here, Zhanget al. report magnetic field-modulated chiral charge pumping and valley diffusion in Cd₃As₂up to room temperature.

It has been predicted that the presence of strong electronic correlations may generate new phases in materials with topologically non-trivial band structure. Here, the authors demonstrate the generation of Dirac mass in the correlated Dirac semimetal candidate ZrTe₅under high magnetic fields.

The Curie temperature of Fe_5+xGeTe₂ thin films can be modulated from 260 to 380 K via iron doping, allowing the two-dimensional material to be used to create planar spiral inductors and low-pass Butterworth filters.

A form of superconductivity where strong spin–orbit coupling combines with topological band inversions to produce strong robustness against magnetic fields is shown in a few-layer transition metal dichalcogenide.

Epitaxial topological heterostructures of (Bi,Sb)₂Te₃/graphene/gallium have been achieved using molecular-beam epitaxy, providing the opportunity to access Majorana zero modes in electrical transport when combined with van der Waals tunnel junctions.

The superconductor-ferromagnet interface provides a unique opportunity to study the interplay between superconductivity and ferromagnetism. Here, the authors build a van der Waals ferromagnetic Josephson junction evidencing a strong 0 and π phase Josephson coupling.

A significant enhancement in the conductance of a graphene nanoribbon field-effect transistor is observed when a perpendicular magnetic field is applied.

Whether the quantum Griffiths singularity state exists in one-dimensional (1D) systems remains elusive. Here, Zhang et al. report violation of the Pauli limit in the superconducting critical field and multiple phase transitions in the current-voltage hysteresis loops in a Ta₂PdS₅ nanowire, suggesting signatures of quasi-1D quantum Griffith singularity.

Unique electronmagnetic response of Weyl semimetals have only been reported in static field regime. Here, the authors report evidence of a dynamical chiral anomaly response realized by internal collective lattice deformation with an external static magnetic field in a Weyl semimetal NbAs.

High mobility and high carrier density are found in the Weyl semimetal NbAs. This is attributed to the low dissipation of disorder-tolerant Fermi arcs.

Here, the authors observe reversible nonreciprocal charge transport in two-dimensional NbSe₂, and demonstrate antenna devices exhibiting strong sensitivity to driving AC electromagnetic waves in the superconducting regime.

Surface superconductivity in a Dirac semimetal remains rarely studied. Here, Huang and Zhou et al. report the evidence of proximity-induced surface superconductivity in a superconductor/Dirac semimetal hybrid system Nb/Cd₃As₂.

A new type of cyclotron orbit combining surface Fermi arcs and bulk states in topological semimetals has recently been proposed as Weyl orbit. Here, Zhang et al. report the evolution of Shubnikov-de Haas oscillations in Dirac semimetal Cd₃As₂ nanoplates along with a quantum Hall state possibly arising from such Weyl orbit.

The magnetic exchange interaction of MnBi₂Te₄—an intrinsic magnetic topological insulator—can be tuned by intercalating ferromagnetic layers of MnTe.

Many topological semimetals are excellent thermoelectric materials, but previous studies were limited to steady-state properties. Here, the authors observe a transient thermoelectric response in Cd₃As₂ by detecting the resulting THz emission, with an enhanced response when a small magnetic field is applied.

The mechanism and scaling of high harmonic generation in solids is a highly compelling ongoing area of research. Here the authors show a non-perturbative behavior of HHG in terahertz regime from 3D Dirac semimetal, Cd₃As₂, at room temperature, and reveal the underlying nonlinear kinetics.

Here, arrays of 2H-TaSe2 nanoribbons are shown to exhibit a broadband plasmonic response that can be tuned from THz to telecom range. These localized plasmons can also couple to charge density wave excitations, offering insights on the physics of plasmonic excitations in 2D correlated materials.

Quantized conductivity is observed along a Weyl orbit in wedge-shaped samples of the topological semimetal Cd₃As₂, providing evidence of the quantum Hall effect in three dimensions.

Employing terahertz nanoscopy, we image highly confined, in-plane anisotropic acoustic terahertz plasmon polaritons in monoclinic Ag₂Te platelets placed above a Au layer, verifying a linear dispersion and elliptical isofrequency contour in momentum space.

The Weyl orbit is a type of cyclotron orbit that appears in topological semimetals. This Perspective discusses the Weyl orbit in the context of the 3D quantum Hall effect and provides an outlook on new phenomena that can arise from these states.

The nonlinear Hall effect enables studies of symmetry and topology with potential in high-frequency devices, but practical applications demand room temperature operation. The authors report robust room temperature nonlinear transverse responses and microwave rectification (1–8 GHz) in MnBi₂Te₄ thin films, driven by extrinsic spin-orbit scattering.