Anomalous magnetoresistance on the topological surface

TL;DR

This paper explores unusual magnetoresistance effects on the surface of topological insulators, revealing how conductance varies with magnetization direction and differs from traditional spin-valve behaviors.

Contribution

It demonstrates novel magnetoresistance phenomena on topological insulator surfaces, highlighting the dependence of conductance on magnetization orientation and contrasting with conventional effects.

Findings

Conductance depends strongly on in-plane magnetization direction.

In p-n junctions, conductance is lower in parallel than in antiparallel configurations.

Anomalous behaviors differ from conventional spin-valve magnetoresistance.

Abstract

We investigate charge transport in two-dimensional ferromagnet/feromagnet junction on a topological insulator. The conductance across the interface depends sensitively on the directions of the magnetizations of the two ferromagnets, showing anomalous behaviors compared with the conventional spin-valve. It is found that the conductance depends strongly on the in-plane direction of the magnetization. Moreover, in sharp contrast to the conventional magnetoresistance effect, in the p-n junction, the conductance at the parallel configuration is much smaller than that at the antiparallel configuration. This stems from the way how the wavefunctions connect between both sides.