Phase transitions induced by resonant light: a phenomenological approach

TL;DR

This paper introduces a phenomenological model extending Landau theory to describe light-induced phase transitions mediated by resonant exciton generation, successfully applied to optical magnetization switching in 2D magnetic materials.

Contribution

It develops a novel phenomenological framework incorporating excitonic fields and dynamic coupling, advancing understanding of resonant light-induced phase transitions in condensed matter.

Findings

Reproduces experimental reverse magnetization in CrI₃ monolayers

Extends Landau theory with excitonic coupling and Langevin forces

Offers a versatile model applicable to various resonant light-induced phenomena

Abstract

We present a phenomenological framework to describe a subclass of light-induced phase transitions (LIPTs) in condensed matter systems, specifically those mediated by the resonant generation of excitons. Our approach extends the classical Landau theory by introducing dynamic coupling between the system's order parameter and complex excitonic fields, along with Langevin-type forces that drive the system toward states of minimal free energy. The model is applied in the context of all-optical resonant magnetization switching in two-dimensional magnetic materials, particularly reproducing the experimental findings for reverse magnetization by all-optical means for a monolayer CrI$_3$. Our phenomenological model can be applied to other systems characterized by an order parameter and excitonic fields created through resonant light, offering versatility and potential to guide future experimental and theoretical studies in LIPT phenomena.