Mechanical Control of Polar State in Antiferroelectric Order

Antiferroelectric thin films can stabilize electrically written metastable polar states, but deterministic reset of these states after electrical writing remains challenging. Here, we demonstrate that localized mechanical force can deterministically erase an electrically written metastable polar state in epitaxial PbHfO₃ thin films, driving the system back toward the antipolar antiferroelectric ground state. Electrical bias stabilizes a persistent metastable polar state, whereas once the polar state is established, tip-applied mechanical force progressively suppresses both piezoresponse and surface-potential contrast, consistent with force-assisted relaxation of the polar state toward the antiferroelectric state. Time-dependent measurements further reveal that the written ferroelectric state is intrinsically metastable and relaxes only slowly without external perturbation. Together, these results demonstrate a deterministic electromechanical write-erase paradigm, in which electric fields encode, and mechanical forces erase ferroic order. This work introduces a new modality for controlling competing ferroic phases and provides a foundation for mechanically reconfigurable nanoelectronic and logic devices based on antiferroelectrics.