Optical Manipulation of Rashba Spin-Orbit Coupling at SrTiO-Based Oxide Interfaces.

Spin-orbit coupling (SOC) plays a crucial role for spintronics applications. Here we present the first demonstration that the Rashba SOC at the SrTiO-based interfaces is highly tunable by photoinduced charge doping, that is, optical gating. Such optical manipulation is nonvolatile after the removal of the illumination in contrast to conventional electrostatic gating and also erasable via a warming-cooling cycle.

Giant photovoltaic effects driven by residual polar field within unit-cell-scale LaAlO₃ films on SrTiO₃.

For polar/nonpolar heterostructures, Maxwell's theory dictates that the electric potential in the polar components will increase divergently with the film thickness. For LaAlO₃/SrTiO₃, a conceptually intriguing route, termed charge reconstruction, has been proposed to avert such "polar catastrophe". The existence of a polar potential in LaAlO₃ is a prerequisite for the validity of the charge reconstruction picture, yet to date, its direct measurement remains a major challenge.