Control of the dipole domain propagation in a GaAs/AlAs superlattice with a high-frequency field

We observed that the propagation of a dipole domain in a GaAs/AlAs superlattice can be controlled by an external high-frequency field. The doped GaAs/AlAs superlattice showed a negative differential conductance giving rise to propagating dipole domains. Depending on the frequency of the high-frequency field, either frequency-locked or quasiperiodic propagating domain states occurred. The behavior can be described by a “devil’s staircase,” where in the locked state the ratio of the external frequency and the domain transit frequency is a rational number. A theoretical analysis indicates that the high-frequency field controls the domain propagation by a modification of both the domain velocity and the shedding of the domains from the cathode.