Light induced magnetization in a spin S=1 easy-plane antiferromagnetic chain

TL;DR

This paper investigates how circularly polarized light can induce and control magnetization in an S=1 antiferromagnetic chain with easy-plane anisotropy, using numerical and analytical methods.

Contribution

It introduces a combined numerical and analytical approach to understand light-induced magnetization in an S=1 chain, including the effects of chirped light frequency.

Findings

Constant frequency light induces specific absorption lines.

Chirped frequency efficiently produces large, controlled magnetization.

A 2-level model qualitatively explains the magnetization process.

Abstract

The time evolution of magnetization induced by circularly polarized light in a $S=1$ Heisenberg chain with large, easy--plane anisotropy is studied numerically and analytically. Results at constant light frequency $\Omega=\Omega_0$ are interpreted in terms of absorption lines of the electronic spin resonance spectrum. Applying a time dependent light frequency $\Omega=\Omega(t)$, so called chirping, is shown to be an efficient procedure in order to obtain within a short time a large, controlled value of the magnetization $M^z$. Furthermore, comparison with a $2$ - level model provides a qualitative understanding of the induced magnetization process.