Terahertz transport in a miniband superlattice under phonon driving

Abstract: We study the nonlinear dynamics and band transport in a semiconductor superlattice driven by a high-frequency acoustic plane wave. The transport characteristics of the system are investigated by using exact path-integral solutions of the Boltzmann transport equation. We show that electron drift and averaged velocities have strongly non-monotonic behavior induced by changing the amplitude of the acoustic wave. These nontrivial kinetic features are associated to some global bifurcations arising in connection with the variation of the control parameter. They cause abrupt transformations of the system phase space and signify the transitions between different dynamical regimes. Additionally, we exhibit that an acoustically pumped superlattice can result in the amplification and generation of terahertz radiation.