Electric Field Tuning of the Rashba Effect in the Polar Perovskite Structures

Original · EN

We show that the Rashba effect at the polar perovskite surfaces and interfaces can be tuned by manipulating the two-dimensional electron gas (2DEG) by an applied electric field, using it to draw the 2DEG out to the surface or push it deeper into the bulk, thereby controlling the surface-sensitive phenomenon. These ideas are illustrated by a comprehensive density-functional study of the recently-discovered polar KTaO₃ surface. Analytical results obtained with a tight-binding model unravel the interplay between the various factors affecting the Rashba effect such as the strength of the spin-orbit interaction and the surface-induced asymmetry. Our work helps interpret the recent experiments on the KTaO₃ surface as well as the SrTiO₃/LaAlO₃ interface.