Carroll, Carson

There is a `universal' picture of a charged domain wall (CDW) in theoretical work, often depicted as residing in an infinite thickness film, charge neutral, and with no bias voltage applied. However, in experiment CDWs are shown with none of these assumptions. CDWs are produced in thin or ultra-thin films, the CDW is not charge neutral, and a bias voltage is being applied. We look to go beyond these assumptions. It was shown that a positively charged domain wall (DW) moves against an external electric field which is not expected. The free electron density was also shown to determine the DW displacement amount. When the film thickness is lowered (ultra-thin film) we get a negatively charged DW which still moves against an external electric field, which agrees with experiment of a CDW in a ultra-thin film. This suggests the charge on the DW does not determine displacement direction.

Author Keywords: charged domain wall, displacement