Anisotropic magnetoresistance in topological insulator Bi1.5Sb0.5Te1.8Se1.2/CoFe heterostructures

TL;DR

This paper reports a new in-plane anisotropic magnetoresistance effect in topological insulator/ferromagnet heterostructures, attributed to spin-momentum locking, resembling giant magnetoresistance phenomena.

Contribution

It introduces a novel in-plane anisotropic magnetoresistance in topological insulator heterostructures and explains it as a giant magnetoresistance effect due to spin-momentum locking.

Findings

Discovery of in-plane anisotropic magnetoresistance

Explanation as giant magnetoresistance effect

Implication for spintronic devices

Abstract

Topological insulator is composed of an insulating bulk state and time reversal symmetry protected two-dimensional surface states. One of the characteristics of the surface states is the locking between electron momentum and spin orientation. Here, we report a novel in-plane anisotropic magnetoresistance in topological insulator Bi1.5Sb0.5Te1.8Se1.2/CoFe heterostructures. To explain the novel effect, we propose that the Bi1.5Sb0.5Te1.8Se1.2/CoFe heterostructure forms a spin-valve or Giant magnetoresistance device due to spin-momentum locking. The novel in-plane anisotropic magnetoresistance can be explained as a Giant magnetoresistance effect of the Bi1.5Sb0.5Te1.8Se1.2/CoFe heterostructures.