Current-voltage characteristics in periodically-driven miniband superlattices

We have theoretically investigated current-voltage characteristics of perio dically-driven GaAs-based miniband superlattice at room temperature by usin g the time-dependent hydrodynamic balance equations. With the amplitude of the ac signal varying in the parameter space, the superlattice is found to exhibit various types of spatiotemporal behavior and current-voltage charac teristics. In the case of a large-amplitude ac signal, the solution is sync hronized with the ac frequency, and the time-averaged current-voltage curve exhibits microwave-radiation-induced de current suppression. A good agreem ent is obtained between the calculated de current and the recent experiment for a GaAs/AlAs miniband superlattice. (C) 2000 Elsevier Science S.A. All rights reserved.