Domain wall migration-mediated ferroelectric switching and Rashba effect tuning in GeTe thin films

TL;DR

This paper investigates the microscopic mechanism of ferroelectric switching in GeTe thin films, revealing domain wall migration as key and demonstrating tunable Rashba effects, which are crucial for future electronic device design.

Contribution

It introduces a microscopic understanding of ferroelectric switching in GeTe via domain wall migration using ab initio methods, and shows how Rashba effects can be tuned during this process.

Findings

Domain wall migration mediates ferroelectric switching with an energy barrier of 66.8 meV/nm².

Rashba effect is tunable through competition between layers with opposite polarization.

Results provide insights for designing GeTe-based electronic devices.

Abstract

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.