High laser harmonics induced by the Berry curvature in time-reversal invariant materials

TL;DR

This paper introduces a novel nonlinear high harmonic generation mechanism in time-reversal invariant materials with broken inversion symmetry, driven by the Berry curvature of electronic bands, supported by a microscopic quasiclassical theory.

Contribution

It develops a microscopic quasiclassical theory linking Berry curvature to high harmonic generation in certain materials, revealing a new nonlinear optical response mechanism.

Findings

Harmonic content can be decoupled by Berry curvature effects.

Nonlinear response depends on laser parameters and system topology.

The theory applies to a broad class of materials with nontrivial band topology.

Abstract

A new nonlinear scheme of high harmonics generation in a wide class of time-reversal invariant materials with broken spatial inversion symmetry (where recently the nonlinear Hall effect has been established) due to the nontrivial topology of bands is proposed. A microscopic quasiclassical theory describing the nonperturbative optical response of pseudo-relativistic electrons with nonzero Berry curvature of bands to a strong laser field is developed. We analyze the harmonic content of the induced current and show that one can decouple induced laser harmonics solely by the Berry curvature of bands. We also study the dependence of the nonlinear response on the driving wave and system parameters.