Photocurrents of charge and spin in single-layer Fe$_3$GeTe$_2$

TL;DR

This study uses first-principles calculations to analyze laser-induced charge and spin photocurrents in single-layer Fe$_3$GeTe$_2$, revealing its potential for optospintronics applications.

Contribution

It introduces a symmetry-based analysis and ab-initio calculations of second-order photocurrents in Fe$_3$GeTe$_2$, highlighting its large charge and spin responses.

Findings

Large charge photocurrent response observed.

Fe$_3$GeTe$_2$ can generate significant laser-induced spin currents.

Photocurrent behavior depends on disorder, frequency, and band filling.

Abstract

In the realm of two-dimensional materials magnetic and transport properties of a unique representative $-$ Fe$_3$GeTe$_2$ $-$ attract ever increasing attention. Here, we use a developed first-principles method for calculating laser-induced response to study the emergence of photo-induced currents of charge and spin in single-layer Fe$_3$GeTe$_2$, which are of second order in the electric field. We provide a symmetry analysis of the emergent photocurrents in the system finding it to be in excellent agreement with ab-initio calculations. We analyse the magnitude and behavior of the charge photocurrents with respect to disorder strength, frequency and band filling. Remarkably, not only do we find a large charge current response, but also predict that Fe$_3$GeTe$_2$ can serve as a source of significant laser-induced spin-currents, which makes this material as a promising platform for various applications in optospintronics.