  Germanium Telluride (GeTe), identified as a ferroelectric Rashba
semiconductor, is a promising candidate for future electronic devices in
computing and memory applications. However, its ferroelectric switching on a
microscopic scale remains to be understood. Here, we propose that the migration
of a domain wall can be the mechanism that mediates the ferroelectric
switching. By employing $ab~initio$ methods, such a mechanism is characterized
by an energy barrier of $66.8$ meV/nm$^2$, in a suitable range for retention
and switchability. In accompanying the domain wall migration, the net Rashba
effect is tunable, as it is a result of competition between layers with
opposite electric polarization. These results shed light on the ferroelectric
switching mechanism in GeTe, paving stones for the design of potential
GeTe-based devices.
