Quantum beat of heavy-hole and light-hole excitons originating from interband Stark-ladder transitions in a biased GaAs/AlAs superlattice

Abstract

Abstract The letter reports the quantum beat of heavy-hole (HH) and light-hole (LH) excitons originating from interband Stark-ladder transitions in a GaAs/AlAs superlattice. Under the condition that the pump photon energy was well below the LH-related transition energy, only Bloch oscillation was observed. As the pump photon energy was increased, another oscillatory signal with a frequency of ∼6 THz was superimposed. The calculation considering related transitions indicates that the oscillation is due to the quantum beat of HH and LH excitons originating from the interband Stark-ladder transitions between the hole states and the electron state in the first-nearest-neighbor quantum wells.