Laser-Driven Multiferroics and Ultrafast Spin Current Generation

TL;DR

This paper presents a method to generate and control spin chirality and spin currents in multiferroic magnets using ultrafast terahertz circularly polarized lasers, enabling dynamic manipulation of magnetic properties.

Contribution

It introduces a novel approach employing Floquet formalism to dynamically control Dzyaloshinskii-Moriya interactions in multiferroics with laser fields, supported by numerical and resonant phenomena analysis.

Findings

Resonant enhancement of spin chirality with magnetic field and laser

Generation of spin current via spatially modulated laser and plasmonic structures

Demonstration of ultrafast control of magnetic interactions

Abstract

We propose an ultrafast way to generate spin chirality and spin current in a class of multiferroic magnets using a terahertz circularly polarized laser. Using the Floquet formalism for periodically driven systems, we show that it is possible to dynamically control the Dzyaloshinskii-Moriya interaction in materials with magnetoelectric coupling. This is supported by numerical calculations, by which additional resonant phenomena are found. Specifically, when a static magnetic field is applied in addition to the circularly polarized laser, a large resonant enhancement of spin chirality is observed resembling the electron spin resonance. Spin current is generated when the laser is spatially modulated by chiral plasmonic structures and could be detected using optospintronic devices.