Anisotropic three-dimensional quantum Hall effect and magnetotransport in mesoscopic Weyl semimetals

Abstract

Weyl semimetals are emerging to become a new class of quantum-material platform for various novel phenomena. Especially, the Weyl orbit made from surface Fermi arcs and bulk relativistic states is expected to play a key role in magnetotransport, leading even to a three-dimensional quantum Hall effect (QHE). It is experimentally and theoretically important although yet unclear whether it bears essentially the same phenomenon as the conventional two-dimensional QHE. We discover an unconventional fully three-dimensional anisotropy in the quantum transport under magnetic field. Strong suppression and even disappearance of QHE occur when Hall-bar current is rotated away from being transverse to parallel with respect to the Weyl point alignment, which is attributed to a peculiar absence of conventional bulk-boundary correspondence. Besides, transport along the magnetic field can exhibit a remarkable reversal from negative to positive magnetoresistance. These results establish the uniqueness of this QHE system as a novel three-dimensional quantum matter.

9 pages, published

References in corpus (9)

• Phase transition between the quantum spin Hall and insulator phases in 3D: emergence of a topological gapless phase
• The Kernel Polynomial Method
• Topological Semimetals
• Chiral Anomaly and Diffusive Magnetotransport in Weyl Metals
• Observation of the quantum Hall effect in confined films of the three-dimensional Dirac semimetal Cd3As2
• Quantum Hall states observed in thin films of Dirac semimetal Cd3As2
• Real-space calculation of the conductivity tensor for disordered topological matter
• Field-Tunable One-Sided Higher-Order Topological Hinge States in Dirac Semimetals
• Quantum Hall effect originated from helical edge states in Cd${}_3$As${}_2$