Antilocalization at an oxide interface

The presence of spin-orbit coupling drives the anomalous magnetotransport at oxide interfaces and forms the basis for numerous intriguing properties of these 2D electron systems, such as topologically protected phases or antilocalization. Formany of those systems, the identification of the underlying couplingmechanism is obfuscated by multiband effects. We therefore analyze the transport of LaAlO3/SrTiO3 interfaces under high pressures, which allows us to single out the multiband contributions. Standard analysis hints at hole as well as electron conductance in our samples. The observed residual magnetoresistance is not related to Coulomb interaction but to weak antilocalization that can be understood within an effective one-band model with spin-orbit coupling causing a threefold spin winding at the Fermi surface. We propose this system to be an excellent candidate to generate a metal-insulator transition of the long-sought symplectic 2D universality class.