High harmonic generation in altermagnets

TL;DR

This paper investigates high harmonic generation in altermagnetic metals, revealing how spin-orbit coupling influences harmonic spectra, introduces dichroism, and affects spin currents, advancing understanding of light-matter interactions in magnetic materials.

Contribution

It provides the first detailed analysis of high harmonic generation in altermagnets, highlighting the roles of spin-orbit coupling and magnetic field dependence in harmonic spectra and dichroism.

Findings

Altermagnetism affects low harmonic dependence on magnetic fields.

Spin-orbit coupling introduces higher energy peaks and plateau structures.

Altermagnets with spin-orbit coupling exhibit circular dichroism in HHG.

Abstract

We study high harmonic generation in altermagnetic metals with and without spin-orbit coupling. The altermagnetism manifests itself in the magnetic field dependence of the low harmonics associated with intra-band dynamics. Spin-orbit coupling leads to additional higher energy peaks and plateau structures originating from inter-band transitions. While the pure altermagnet or spin-orbit system exhibits no circular dichroism in the high-harmonic response, an altermagnetic system with spin-orbit coupling shows such a dichroism. We also analyze the spin currents and their high harmonic spectrum.