Light-induced Magnetization by Quantum Geometry

TL;DR

This paper introduces a quantum-geometry-based mechanism for light-induced magnetization, linking quantum metric properties to nonlinear magneto-optical effects, and provides a formalism for their analysis and potential experimental detection.

Contribution

It presents a novel quantum-geometric framework for understanding light-induced magnetization, connecting quantum metric quadrupoles to observable magneto-optical responses.

Findings

Quantum geometry influences nonlinear magneto-optical effects.

Symmetry constraints affect the magnitude of light-induced magnetization.

Estimated magnetizations suggest experimental detectability.

Abstract

We propose a mechanism for the inverse Faraday and the inverse Cotton--Mouton effects arising from quantum geometry, characterized by the quantum metric quadrupole and the weighted quantum metric. Within a semiclassical framework based on the Boltzmann transport theory, we establish a general formalism describing light-induced magnetization in electronic systems as a second-order response to the electric field of light. Using continuum and tight-binding models, we discuss the symmetry constraints on these effects and estimate the magnitudes of the resulting magnetizations. Our results highlight a direct manifestation of quantum-geometric quantities in nonlinear magneto-optical responses and suggest a viable pathway for experimental detection.