Miniband transport in a GaAs/AlAs superlattice with submonolayer barriers in a static and THz electric field

Abstract

We report on the observation of miniband transport in a GaAs/AlAs superlattice with AlAs barrier layers of submonolayer thickness. The current–voltage characteristic of the superlattice at static electric fields showed a negative differential conductance, which is related to miniband electrons performing Bloch oscillations. Under the influence of a THz field, the current through the superlattice was reduced due to a dynamic localisation of the miniband electrons. Our results showed that the novel superlattice can be used as THz detector with a dynamic range of six orders of magnitude and with a responsivity of 0.2 V/W.