Antilocalization in oxides: Effective spin-3/2 model

Weak antilocalization offers an experimental tool to address spin-orbit coupling of two-dimensional oxide surfaces and interfaces via magnetotransport. To overcome the shortcomings of the formulation for single-band spin-1/2 electrons, we consider an effective three-band model that allows a decomposition into a pseudospin representation 1/2 circle plus 3/2. Whereas the well-established spin-1/2 transport signature results from singlet and triplet channels in the Cooperon equation, a new structure originates from the quintet and septet channels generated by the spina 3/2 circle times 3/2 representations.