Photoinduced control of ferroelectricity in hybrid-improper ferroelectric superlattices

We reveal a photoinduced control of ferroelectricity in hybrid-improper ferroelectric superlattices, using ab initio theory. Along with a notable photostriction effect, thermalized carriers from photoexcitation affect octahedral tiltings along different directions. A trilinear coupling between antipolar and tilting modes drives corresponding cationic displacements, and this results in a decrease in polarization under light. Together with recent experimental evidence, our study therefore demonstrates that light is a viable route to engineer functionalities in materials.