Chiral Edge Conduction on Domain Walls of a Magnetic Topological Insulator

Abstract

Topological phases of matter have been extensively studied both theoretically and experimentally for their characteristic band structures and exotic transport phenomena. Here, we review quantum anomalous Hall effect as one such example from the viewpoint of topological phases and related experimental results. Quantum anomalous Hall effect has been observed in a magnetic topological insulator Cr doped (Bi_1-y Sb_y)₂Te₃ thin films, where the spontaneous magnetization induces one-dimensional chiral transport at the edge of the sample. Recent experiments have demonstrated the existence of the chiral edge conduction also along the magnetic domain wall in the sample. By introducing Landauer Büttiker formula, the one-to-one correspondence between the fabricated domain wall and the chiral edge conduction was confirmed. This enables us to construct reconfigurable dissipationless circuit with the control of the domain structure.