| Abstract: | One of the most fundamental phenomena and a reminder of the electron's relativistic nature is the Rashba spin splitting for broken inversion symmetries in two‐dimensional condensed matter systems. Typically, this splitting is a tiny relativistic correction. By coupling ferroelectric BaTiO3 and a 5d (or 4d) transition metal oxide with a large spin‐orbit coupling, Ba(Os,Ir,Ru)O3, it is shown that giant Rashba spin splittings are indeed possible and even controllable by an external electric field. Based on density functional theory and a microscopic tight binding understanding, it is concluded that the electric field is amplified and stored as a ferroelectric Ti‐O distortion which, through the network of oxygen octahedra, induces a large (Os,Ir,Ru)‐O distortion. The BaTiO3/Ba(Os,Ru,Ir)O3 heterostructure is hence the ideal test station for switching and studying the Rashba effect and allows applications at room temperature. |
