Domain Wall Acceleration by Ultrafast Field Application: An Ab Initio-Based Molecular Dynamics Study

TL;DR

This study uses ab initio-based molecular dynamics to explore how ultrafast electric fields influence domain wall motion in ferroelectric BaTiO3, revealing a giant velocity boost linked to local dipole switching.

Contribution

It provides new insights into the microscopic mechanisms of ferroelectric domain wall dynamics under ultrafast fields using advanced simulations.

Findings

Giant boost in domain wall velocity observed.

Ultrafast fields excite dipoles, affecting wall motion.

Potential to tune switching rates via pulse shape.

Abstract

Optimizing ferroelectrics for contemporary high-frequency applications asks for the fundamental understanding of ferroelectric switching and domain wall (DW) motion in ultrafast field pulses while the microscopic understanding of the latter is so far incomplete. To close this gap in knowledge, ab initio-based molecular dynamics simulations are utilized to analyze the dynamics of 180$^\grad# DWs in the prototypical ferroelectric material BaTiO 3 . How ultrafast field application initially excites the dipoles in the system and how they relax to their steady state via transient negative capacitance are discussed. Excitingly, a giant boost of the DW velocity related to the nonequilibrium switching of local dipoles acting as nucleation centers for the wall movement is found. This boost may allow to tune the local ferroelectric switching rate by the shape of an applied field pulse.