Spin-orbit coupled superconductivity at the interface of LaAlO3/SrTiO3

We have grown few unit cells of epitaxial LaAlO3 (LAO) on TiO2 terminated SrTiO3 (STO) substrates using oxide MBE technique, which shows an interface superconductivity below about 0.3 K. By fabricating a back gate electrode via the STO substrate, the superconductor-to-insulator transition was observed by applying gate voltages on a macroscopic size of the two-dimensional electron liquid (2DEL) at the interface of LAO/STO. From the superconducting critical field anisotropy measurements, a sizable spin-orbit coupling is found to present in the superconducting phase, where the upper limit of the spin-orbit coupling strength can be largely tuned by gate voltages. In addition, magnetotransport anomaly was observed when depleting the electron density and thus driving the 2DEL into insulating phase, suggesting an inhomogeneous density distribution and also a possible multiband conduction in the 2DEL.