Domain Wall-mediated Interfacial Ferroelectric Switching

TL;DR

This study uncovers how different domain wall types influence polarization switching in interfacial ferroelectrics, combining computational and experimental approaches to propose strategies for stable, non-volatile memory devices.

Contribution

It provides a comprehensive understanding of domain wall roles in polarization switching and introduces new strategies for achieving non-volatile ferroelectric memory.

Findings

Different domain wall types lead to distinct switching behaviors.

Domain walls respond to electric fields via polarization vector deviation.

Strategies beyond ideal conditions enable non-volatile switching.

Abstract

Interfacial ferroelectricity offers a promising platform for ultrafast, low-power memory devices. While previous studies have demonstrated the importance of domain wall in polarization switching, the coexistence of various domain wall types and their impact on polarization stability lacks fundamental understanding. By integrating first-principles calculations, machine learning methods, and experimental validations, we show that domain walls connect opposite polarization states and respond to out-of-plane electric field through polarization vector deviation, leading to inhomogeneous interlayer sliding and domain-wall migration. This mechanism bears clear resemblance to that in traditional ferroelectrics. Notably, different domain wall types result in distinct switching behaviors, which play a crucial role in determining the reversibility of polarization switching. We then propose strategies beyond ideal conditions to achieve non-volatile ferroelectric switching, which are supported by our experimental observations. These insights shed light on the microscopic switching mechanism in hexagonal interfacial ferroelectrics, offering guidance for future nanoelectronics applications.