We study the symmetry of Cooper pair in a two-dimensional Hubbard model with the Rashba-type spin-orbit interaction as a minimal model of electron gas generated at a heterointerface of SrTiO3/LaAlO3. Solving the Iliashberg equation based on the third-order perturbation theory, we find that the gap function consists of the mixing of the spin-singlet dxy -wave component and the spin-triplet (px ±ipy) -wave one due to the broken inversion symmetry originating from the Rashba-type spin-orbit interaction. The ratio of the d -wave and the p -wave component continuously changes with the carrier concentration. We propose that the pairing symmetry is controlled by tuning the gate voltage.
|Physical Review B - Condensed Matter and Materials Physics
|Published - Oct 20 2009
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics