Hinge Spin Polarization in Magnetic Topological Insulators Revealed by Resistance Switch

TL;DR

This paper demonstrates a method to detect hinge spin polarization in magnetic topological insulators through resistance measurements, revealing local spin features and enabling spin-sensitive device design.

Contribution

It introduces a three-dimensional model and multi-terminal device setup to unveil hinge spin polarization and resistance switching in magnetic topological insulators.

Findings

Hinge spin polarization inverts between top and bottom surfaces.

Large resistance switch observed between forward and backward states.

Method applicable across various magnetic phases.

Abstract

We report on the possibility to detect hinge spin polarization in magnetic topological insulators by resistance measurements. By implementing a three-dimensional model of magnetic topological insulators into a multi-terminal device with ferromagnetic contacts near the top surface, local spin features of the chiral edge modes are unveiled. We find local spin polarization at the hinges that inverts sign between top and bottom surfaces. At the opposite edge, the topological state with inverted spin polarization propagates in the reverse direction. Large resistance switch between forward and backward propagating states is obtained, driven by the matching between the spin polarized hinges and the ferromagnetic contacts. This feature is general to the ferromagnetic, antiferromagnetic and canted-antiferromagnetic phases, and enables the design of spin-sensitive devices, with the possibility of reversing the hinge spin polarization of the currents.