Electronic properties of type-II Weyl semimetal WTe${}_2$. A review perspective

Abstract

Currently, there is a flurry of research interest on materials with an unconventional electronic structure, and we have already seen significant progress in their understanding and engineering towards real-life applications. The interest erupted with the discovery of graphene and topological insulators in the previous decade. The electrons in graphene simulate massless Dirac Fermions with a linearly dispersing Dirac cone in their band structure, while in topological insulators, the electronic bands wind non-trivially in momentum space giving rise to gapless surface states and bulk bandgap. Weyl semimetals in condensed matter systems are the latest addition to this growing family of topological materials. Weyl Fermions are known in the context of high energy physics since almost the beginning of quantum mechanics. They apparently violate charge conservation rules, displaying the "chiral anomaly", with such remarkable properties recently theoretically predicted and experimentally verified to exist as low energy quasiparticle states in certain condensed matter systems. Not only are these new materials extremely important for our fundamental understanding of quantum phenomena, but also they exhibit completely different transport phenomena. For example, massless Fermions are susceptible to scattering from non-magnetic impurities. Dirac semimetals exhibit non-saturating extremely large magnetoresistance as a consequence of their robust electronic bands being protected by time reversal symmetry. These open up whole new possibilities for materials engineering and applications including quantum computing. In this review, we recapitulate some of the outstanding properties of WTe${}_2$, namely, its non-saturating titanic magnetoresistance due to perfect electron and hole carrier balance up to a very high magnetic field observed for the very first time. (Continued. Please see the main article).

33 pages, 7 figures

References in corpus (17)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Topological Insulators with Inversion Symmetry
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Valley polarization in MoS2 monolayers by optical pumping
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• Titanic Magnetoresistance in WTe2
• Observation of the Quantum Spin Hall Effect up to 100 Kelvin in a Monolayer Crystal
• Discovery of Weyl fermion semimetals and topological Fermi arc states
• Electronic structure basis for the titanic magnetoresistance in WTe${}_2$
• Quantum oscillations, thermoelectric coefficients and the Fermi surface of semi-metallic WTe2
• Weyl semimetals from noncentrosymmetric topological insulators
• Anisotropic Magnetotransport and Exotic Longitudinal Linear Magnetoresistance in WTe2 Crystals
• Magnetoresistance in two-component systems
• Surface Fermi arc connectivity in the type-II Weyl semimetal candidate WTe${}_2$
• Three-dimensional band structure of layered TiTe2: Photoemission final-state effects
• Enhanced ultrafast relaxation rate in the Weyl semimetal phase of $\mathbf{MoT}{\mathbf{e}}_2$ measured by time-and angle-resolved photoelectron spectroscopy

Cited by in corpus (12)

• Light control with Weyl semimetals
• Progress in epitaxial thin-film Na3Bi as a topological electronic material
• Fermi surface and nested magnetic breakdown in WTe2
• Thickness Dependence of Magneto-transport Properties in Tungsten Ditelluride
• Theory of Glide Symmetry Protected Helical Edge States in WTe${}_2$ Monolayer
• Terahertz control of surface topology probed with subatomic resolution
• High Landau levels of 2D electrons near the topological transition caused by interplay of spin-orbit and Zeeman energy shifts
• Optical conductivity of the type-II Weyl semimetal WTe${}_2$ under pressure
• Electronic transport and Fermi surface of Weyl semimetal WTe2: quantum oscillations and first-principles study
• Electronic structure of 2D van der Waals crystals and heterostructures investigated by spatially- and angle-resolved photoemission
• Electronic band structure from quasiparticle interference and Landau quantization in WTe${}_2$
• `Interaction annealing' to determine effective quantized valence and orbital structure: an illustration with ferro-orbital order in WTe${}_2$