Direct current generation due to wave mixing in semiconductor superlattices

Summary form only given. Recently, we showed that a THz-electric field without constant bias can create a constant voltage and corresponding direct current (DC) in a single miniband semiconductor superlattice (SSL). The rectification results from an interplay of dissipation (scattering of ballistic electrons with impurities and phonons) and generation of a self-consistent electric field along the SSL axis, which is a strongly nonlinear effect. In this report, we consider another scheme of THz-field rectification in SSL, namely a rectification at wave mixing. Our finding is that a DC can be generated in SSL at mixing of waves with commensurate frequencies. The origin of this effect is related to a nonparabolicity of the energy spectrum of SSL.