Circular photogalvanic effects in topological insulator/ferromagnet hybrid structures

TL;DR

This paper investigates laser-induced spin-current effects at ferromagnet/topological-insulator interfaces using high-resolution photocurrent measurements and terahertz emission, revealing dynamic interactions at the interface.

Contribution

It introduces experimental methods to study spin-current effects in ferromagnet/topological-insulator structures, highlighting dynamic and lateral interface interactions.

Findings

Detection of laser-driven photocurrents with high spatial resolution

Observation of terahertz emission indicating dynamic interface currents

Evidence of lateral and dynamic interactions at the interface

Abstract

We study laser driven spin-current effects at ferromagnet/topological-insulator interfaces by two complementary experimental approaches. The DC photocurrent is studied in ferromagnet/topological-insulator bilayers with high spatial resolution. Dynamic interface currents are explored via the emission of terahertz radiation emitted by these currents with high temporal resolution. From our experiments, we reveal a lateral and dynamic interaction of the ferromagnet and the topological insulator interface.