THz parametric gain in semiconductor superlattices in the absence of electric domains

TL;DR

This paper theoretically demonstrates that semiconductor superlattices can achieve THz parametric gain at even harmonics without forming electric domains, by exploiting the parametric effects of high-frequency electric fields.

Contribution

It reveals that conditions for THz gain and electric domain formation are distinct, enabling domain-free THz amplification in superlattices.

Findings

Significant THz gain at even harmonics without electric domains.

High-frequency electric fields induce periodic energy and effective mass variations.

Parametric effects enable domain-free THz amplification.

Abstract

We theoretically show that conditions for THz gain and conditions for formation of destructive electric domains in semiconductor superlattices are fairly different in the case of parametric generation and amplification. Action of an unbiased high-frequency electric field on a superlattice causes a periodic variation of energy and effective mass of miniband electrons. This parametric effect can result in a significant gain at some even harmonic of the pump frequency without formation of electric domains and corruption from pump harmonics.