Relocation time of the domain boundary in weakly coupled GaAs/AlAs superlattices

Static domain formation in doped semiconductor superlattices results in many branches in the current-voltage characteristic separated by a discontinuity in the current. The transition process from one branch to the next has been studied experimentally by adding an ac bias with different amplitudes to a dc bias close to a discontinuity and recording the time-resolved current. The relocation time of the domain boundary depends exponentially on the difference between the final static current and the maximum or minimum current value of the corresponding branch, which is reached before the relocation of the domain boundary takes place. A universal relationship between the relocation time and the current difference has been observed.