Optical amplification in a CDW-phase of a quasi-two dimensional material

TL;DR

This paper presents a theoretical study of optical amplification in a quasi-two dimensional charge-density-wave material, highlighting the effects of electron-hole and electron-phonon interactions on phase quenching and proposing a high-frequency mid-infrared amplification mechanism.

Contribution

It introduces a microscopic dynamical model for phase quenching in CDW materials considering both interactions and suggests a novel optical amplification effect in the mid-infrared.

Findings

Interaction processes influence anomalous expectation values.

Time-dependent appearance of additional bands observed.

Proposed high-frequency optical amplification in mid-infrared.

Abstract

We study theoretically the quenching of a charge-density-wave phase in a model system of a quasi-two dimensional material, which includes both electron-hole and electron-phonon interactions leading, respectively to excitonic and coherent-phonon contributions. We discuss how interaction processes affect anomalous expectation values and present a microscopic dynamical picture of the quenching of the phase. We use projection techniques to illustrate the time-dependent appearance of additional bands and anomalous expectation values. We propose an optical amplification effect with a high modulation frequency in the mid-infrared regime.