Work

Engineering chiral edge states in two-dimensional topological insulator/ferromagnetic insulator heterostructures

Year: 2019

Type: article

Abstract: The chiral edge state (CES) at zero magnetic field has already been realized in the magnetically doped topological insulator (TI). However, this scheme strongly relies on material breakthroughs, and in fact, most of the TIs cannot be driven into a Chern insulator in this way. Here, we propose to achieve the CESs in two-dimensional TI/ferromagnetic insulator/TI sandwiched structures through spin-selective coupling between the helical edge states of the two TIs. Due to this coupling, the edge states of one spin channel are gapped and those of the other spin channel remain almost gapless, so that the helical edge states of each isolated TI are changed into the CESs. Such CESs can be hopefully achieved in all TI materials, which are immune to magnetic-disorder-induced backscattering. We propose to implement our scheme in the van der Waals heterostructures between monolayer $1{T}^{\ensuremath{'}}\text{\ensuremath{-}}{\mathrm{WTe}}_{2}$ and bilayer ${\mathrm{CrI}}_{3}$. The electrical control of magnetism in bilayer ${\mathrm{CrI}}_{3}$ switches the transport direction of the CESs, which can realize a low-consumption transistor.

Source: Physical review. B./Physical review. B

DOI: 10.1103/physrevb.99.085417

Authors: Xi-Rong Chen, Wei Chen, L. B. Shao, D. Y. Xing