Coupled spin-charge transport in oxide interface

Abstract

A two-dimensional (2D) electron gas emerged at a LaAlO3/SrTiO3 (LAO/STO) interface is an interesting electronic platform as the structure itself has broken inversion symmetry. This noncentrosymmetric 2D conductor retains Rashba-type spin-orbit interaction, which ties spin and momentum of electrons in the band structure leading to coupled spin and charge transport. In this talk, I will present coupled spin-charge transport in LAO/STO interface evidenced in various experimental platforms. We demonstrated the non-local spin diffusion in conducting interface of LAO/STO using H-bar type structure, where the spin Hall and its inverse effect function as the spin injector and detector [1]. The inherent structural asymmetry in the conductive oxide interface can induce further intriguing transport properties. When the time-reversal symmetry is further broken, the system could exhibit directional propagation of itinerant electrons, i.e. the rightward and leftward currents differ from each other. In addition, the Rashba spin-orbit interaction can be further tuned by applying gate bias, so does the nonreciprocal charge transport [2].