  A numerical study of domain wall relocation during voltage switching with
different ramping times is presented for weakly coupled, doped semiconductor
superlattices exhibiting multistable domain formation in the first plateau of
their current-voltage characteristics. Stable self-oscillations of the current
at the end of stable stationary branches of the current-voltage characteristics
have been found. These oscillations are due to periodic motion of charge
dipoles near the cathode that disappear inside the SL, before they can reach
the receiving contact. Depending on the dc voltage step, the type of
multistability between static branches and the duration of voltage switching,
unusual relocation scenarios are found including changes of the current that
follow adiabatically the stable I--V branches, different faster episodes
involving charge tripoles and dipoles, and even small amplitude oscillations of
the current near the end of static I--V branches followed by dipole-tripole
scenarios.
