Rashba splitting is a phenomenon that occurs in certain types of materials, including some perovskite materials. In these materials, the spin-orbit coupling (SOC) interaction can lead to a splitting of the energy levels in the electronic band structure.
In perovskites with heavy elements, such as lead or bismuth, the SOC interaction can be strong enough to cause Rashba splitting. This splitting can lead to the formation of spin-polarized states at the band edges, which have potential applications in spintronics and other fields.