Terahertz Bloch oscillator with suppressed electric domains: Effect of elastic scattering

TL;DR

This paper theoretically explores how to amplify terahertz radiation in superlattice Bloch oscillators while suppressing electric domain instabilities by extending the Kroemer scheme with different electron relaxation times.

Contribution

It introduces an extended model considering distinct relaxation times for electron velocity and energy, enhancing the applicability of the Kroemer scheme for THz Bloch oscillators.

Findings

Extended the Kroemer scheme to include different electron relaxation times.

Analyzed the electron and field kinetics for stationary signal establishment.

Proposed conditions for achieving gain while avoiding space-charge instabilities.

Abstract

We theoretically consider the amplification of THz radiation in a superlattice Bloch oscillator. The main dilemma in the realization of THz Bloch oscillator is finding operational conditions which allow simultaneously to achieve gain at THz frequencies and to avoid destructive space-charge instabilities. A possible solution to this dilemma is the extended Limited Space-Charge Accumulation scheme of Kroemer (H. Kroemer, cond-mat/0009311). Within the semiclassical miniband transport approach we extend its range of applicability by considering a difference in the relaxation times for electron velocity and electron energy. The kinetics of electrons and fields establishing a stationary signal in the oscillator is also discussed.