Predicting the Electro-Optic Response of BaTiO₃ Thin Films using Phase-Field Simulations

Optimizing the optical properties of ferroelectric materials is crucial to next-generation applications such as quantum computers and data centers. However, conventional theoretical approaches cannot realistically simulate the complex nanoscale domain structures of these materials. Here we explore a new theoretical approach, which utilizes the thermodynamic theory of optical properties and phase-field simulations to resolve these nanoscale features. Our approach is able to predict the optical properties of ferroelectric thin films, including at previously incalculable cryogenic temperatures, which are in excellent agreement with experiment. In this study we predicted the temperature- and strain-dependent electro-optic properties of BaTiO₃ thin films under applied electric fields in varying directions and investigated the relationship between the mechanical boundary conditions, domain structure, and electro-optic properties of BaTiO₃ thin films.