Undamped Soliton-like Domain Wall Motion in Sliding Ferroelectrics

TL;DR

This paper predicts undamped, soliton-like domain wall motion in sliding ferroelectrics, revealing ultrafast, fatigue-resistant polarization switching with potential for memory device applications.

Contribution

It introduces a novel undamped domain wall motion in sliding ferroelectrics, combining machine learning and field theory to uncover relativistic-like velocity limits.

Findings

Domain walls exhibit uniformly accelerated motion under external fields.

Velocity reaches a relativistic-like limit due to continuous acceleration.

Domain wall velocity remains constant after external field removal.

Abstract

Sliding ferroelectricity in bilayer van der Waals materials exhibits ultrafast switching speed and fatigue resistance during the polarization switching, offering an avenue for the design of memories and neuromorphic devices. The unique polarization switching behavior originates from the distinct characteristics of domain wall (DW), which possesses broader width and faster motion compared to conventional ferroelectrics. Herein, using machine-learning-assisted molecular dynamics simulations and field theory analysis, we predict an undamped soliton-like DW motion in sliding ferroelectrics. It is found that the DW in sliding ferroelectric bilayer 3R-MoS2 exhibits uniformly accelerated motion under an external field, with its velocity ultimately reaches the relativistic-like limit due to continuous acceleration. Remarkably, the DW velocity remains constant even after the external field removal, completely deviating from the velocity breakdown observed in conventional ferroelectrics. This work provides opportunities for applications of sliding ferroelectrics in memory devices based on DW engineering.