Gate tunable Rashba spin-orbit coupling at CaZrO3/SrTiO3 heterointerface

Abstract

High mobility quasi two-dimensional electron gas (2DEG) found at the CaZrO3/SrTiO3 nonpolar heterointerface is attractive and provides a platform for the development of functional devices and nanoelectronics. Here we report that the carrier density and mobility at low temperature can be tuned by gate voltage at the CaZrO3/SrTiO3 interface. Furthermore, the magnitude of Rashba spin–orbit interaction can be modulated and increases with the gate voltage. Remarkably, the diffusion constant and the spin–orbit relaxation time can be strongly tuned by gate voltage. The diffusion constant increases by a factor of ∼ 19.98 and the relaxation time is reduced by a factor of over three orders of magnitude while the gate voltage is swept from –50 V to 100 V. These findings not only lay a foundation for further understanding the underlying mechanism of Rashba spin–orbit coupling, but also have great significance in developing various oxide functional devices.