Quantized chiral edge conduction on reconfigurable domain walls of a magnetic topological insulator

TL;DR

This paper demonstrates the creation and control of quantized chiral edge conduction along magnetic domain walls in a topological insulator, enabling reconfigurable dissipation-less electronic pathways.

Contribution

It provides the first experimental realization of reconfigurable chiral edge states on magnetic domain walls in a topological insulator, combining design, fabrication, and proof-of-concept device demonstrations.

Findings

Confirmed the existence of chiral edge conduction along magnetic domain walls.

Demonstrated reconfigurability of domain wall channels using magnetic force microscopy.

Validated device operation with Landauer-Buttiker formalism.

Abstract

The electronic orders in magnetic and dielectric materials form the domains with different signs of order parameters. The control of configuration and motion of the domain walls (DWs) enables gigantic, nonvolatile responses against minute external fields, forming the bases of contemporary electronics. As an extension of the DW function concept, we realize the one-dimensional quantized conduction on the magnetic DWs of a topological insulator (TI). The DW of a magnetic TI is predicted to host the chiral edge state (CES) of dissipation-less nature when each magnetic domain is in the quantum anomalous Hall state. We design and fabricate the magnetic domains in a magnetic TI film with the tip of the magnetic force microscope, and clearly prove the existence of the chiral one-dimensional edge conduction along the prescribed DWs. The proof-of-concept devices based on the reconfigurable CES and Landauer-Buttiker formalism are exemplified for multiple-domain configurations with the well-defined DW channels.