Observation of one-dimensional, charged domain walls in ferroelectric ZrO2.

Ferroelectric charged domain walls (CDWs) with nanoscale thickness and bound charges are typically viewed as ultrathin, reconfigurable, and highly conductive two-dimensional components for domain wall nanoelectronics. Dimensional confinement of such polar topological structures has the potential to increase device density and unlock novel functionalities. We report 180° head-to-head and tail-to-tail CDWs exhibiting one-dimensional (1D) characteristics. These 1D CDWs are confined within the polar layers of ferroelectric ZrO2 and have atomic-scale dimensions in both width and thickness. Quantitative analysis unveils a distinct screening mechanism of these walls whereby bound polarization charges are compensated by self-balancing oxygen occupancy. We demonstrate electric field-driven manipulation of these 1D CDWs, revealing the microscopic coupling between polarization switching and oxygen-ion transport.