Sub-terahertz amplification in a semiconductor superlattice with moving charge domains

Abstract

We theoretically study the high-frequency response of charge domains traveling through a strongly coupled semiconductor superlattice with an applied harmonic electromagnetic signal. Our calculations show that the superlattice alone can amplify signals with a frequency close to the domain transient frequency. Moreover, we show that if the superlattice is connected to a resonator, amplification becomes possible for much higher frequencies of the external signal (several hundred GHz). These promising results open the way to using semiconductor superlattices as efficient sub-THz amplifiers.