Creation of independently controllable and long lifetime polar skyrmion textures in ferroelectric-metallic heterostructures

TL;DR

This paper demonstrates the creation and control of long-lifetime polar skyrmion textures in ferroelectric-metallic heterostructures, revealing their stability, controllability, and potential for topological state applications.

Contribution

It introduces a method to stabilize and manipulate diverse polar skyrmion textures with extended lifetimes in ferroelectric heterostructures, a significant advancement over previous short-lived skyrmions.

Findings

Skyrmion textures stabilized with lifetimes over two weeks.

Electrical and mechanical stimuli enable writing, erasing, and reading skyrmions.

Heterostructures exhibit electric Dzyaloshinskii-Moriya interactions.

Abstract

Topological textures like vortices, labyrinths and skyrmions formed in ferroic materials have attracted extensive interests during the past decade for their fundamental physics, intriguing topology, and technological prospects. So far, polar skyrmions remain scarce in ferroelectrics as they require a delicate balance between various dipolar interactions. Here, we report that PbTiO3 thin films in a metallic contact undergo a topological phase transition and stabilize a broad family of skyrmion-like textures (e.g., skyrmion bubbles, multiple {\pi}-twist target skyrmions, and skyrmion bags) with independent controllability, analogous to those reported in magnetic systems. Weakly-interacted skyrmion arrays with a density over 300 Gb/inch2 are successfully written, erased and read-out by local electrical and mechanical stimuli of a scanning probe. Interestingly, in contrast to the relatively short lifetime <20 hours of the skyrmion bubbles, the multiple {\pi}-twist target skyrmions and skyrmion bags show topology-enhanced stability with lifetime over two weeks. Experimental and theoretical analysis implies the heterostructures carry electric Dzyaloshinskii-Moriya interaction mediated by oxygen octahedral tiltings. Our results demonstrate ferroelectric-metallic heterostructures as fertile playground for topological states and emergent phenomena.