Atomic-scale theory of robust out-of-plane ferroelectricity in ultrathin films
This paper develops an atomic-scale theoretical framework explaining how robust out-of-plane ferroelectricity persists in ultrathin HfO- and bismuth-based films through "self-polarizing" and "switchable role of the termination layer" effects driven by characteristic structures and electrode interactions, thereby guiding the design of next-generation nanoelectronic devices.