The Effect of Multiple Conduction Bands on High Harmonic Emission from Dielectrics

TL;DR

This paper demonstrates that transitions between multiple conduction bands significantly influence high harmonic generation in dielectrics under strong mid-IR fields, offering a new spectroscopic approach to probe electron dynamics.

Contribution

It reveals the crucial role of inter-conduction band transitions in high harmonic emission and introduces a method to use harmonic spectra for studying effective band structures.

Findings

Inter-conduction band transitions enhance harmonic signals.

Harmonic spectra can reveal effective band structures.

Transitions can create a single effective band for electrons.

Abstract

We find that, for sufficiently strong mid-IR fields, transitions between different conduction bands play an important role in the generation of high-order harmonics in a dielectric. The transitions make a significant contribution to the harmonic signal, and they can create a single effective band for the motion of an electron wave packet. We show how high harmonic spectra produced during the interaction of ultrashort laser pulses with periodic solids provide a spectroscopic tool for understanding the effective band structure that controls electron dynamics in these media.