Theory of parametric amplification in in superlattices

Abstract

We consider a high-frequency response of electrons in a single miniband of superlattice subject to dc and ac electric fields. We show that Bragg reflections in miniband result in a parametric resonance which is detectable using ac probe field. We establish theoretical feasibility of phase-sensitive THz amplification at the resonance. The parametric amplification does not require operation in conditions of negative differential conductance. This prevents a formation of destructive high-field domains inside the superlattice.

4 pages, 4 figures. V2: typo in axis caption of fig 2 is corrected. V3: typo in ref 9 is corrected, stylistic changes in the main text, new refs 18-21 are added, and change in the title