Large Magnetoresistance at Room Temperature in Ferromagnet/Topological Insulator Contacts

TL;DR

This study demonstrates significant room-temperature magnetoresistance in ferromagnet/topological insulator contacts, linked to spin-momentum locking, with potential implications for spintronic devices.

Contribution

It reports large magnetoresistance at room temperature in Fe/TI contacts, highlighting the role of spin-momentum locking in surface states.

Findings

Magnetoresistance observed at temperatures from 100 K to room temperature.

Magnetoresistance magnitude is larger than in previous studies.

Magnetoresistance is related to the relative orientation of magnetization and electron spin polarization.

Abstract

We report magnetoresistance for current flow through iron/topological insulator (Fe/TI) and Fe/evaporated-oxide/TI contacts when a magnetic field is used to initially orient the magnetic alignment of the incorporated ferromagnetic Fe bar, at temperatures ranging from 100 K to room temperature. This magnetoresistance is associated with the relative orientation of the Fe bar magnetization and spin-polarization of electrons moving on the surface of the TI with helical spin-momentum locking. The magnitude of the observed magnetoresistance is relatively large compared to that observed in prior work.