Effect of chiral selective tunneling on quantum transport in magnetic topological-insulator thin films

TL;DR

This paper investigates how chiral selective tunneling influences quantum transport in magnetic topological-insulator thin films, revealing mechanisms for current blocking and potential for electronic device design.

Contribution

It demonstrates that chiral transition rules govern transport gaps in magnetic topological insulators and how these rules are affected by structural asymmetries and in-plane magnetization.

Findings

Chiral selective tunneling causes transport gaps and current blocking.

Transport behavior is altered by structural inversion asymmetry and in-plane magnetization.

Potential for designing devices with negative differential resistance.

Abstract

The electronic transport properties in magnetically doped ultra-thin films of topological-insulators is investigated by using Landauer-buttiker formalism. The chiral selective tunneling is addressed in such systems which leads to transport gap and as a consequence current blocking. This quantum blocking of transport occurs when the magnetic states with opposite chirality are aligned energetically. This can be obsereved when an electron tunnels through a barrier or well of magnetic potential induced by the exchange field. It is proved and demonstrated that this chiral transition rule fails when structural inversion asymmetric potential or an in-plane magnetization is turning on. This new finding is useful to interpret quantum transport through topological-insulator thin films especially to shed light on longitudinal conductance behavior of quantum anomalous Hall effect. Besides, one can design electronic devices by means of magnetic topological-insulator thin films based on the chiral selective tunneling leading to negative differential resistance.