Link between the superconducting dome and spin-orbit interaction in the (111) LaAlO₃/SrTiO₃ interface

We measure the gate voltage (V_g) dependence of the superconducting properties and the spin-orbit interaction in (111) oriented LaAlO₃/SrTiO₃ interface. Superconductivity is observed in a dome-shaped region in the carrier density-temperature phase diagram with the maxima of superconducting transition temperature T_c and the upper critical fields lying at the same V_g. The spin-orbit interaction determined from the superconducting parameters and confirmed by weak-antilocalisation measurements follows the same gate voltage dependence as T_c. The correlation between superconductivity and spin-orbit interaction as well as the enhancement of parallel upper critical field, well beyond the Chandrasekhar-Clogston limit suggest that superconductivity and the spin-orbit interaction are linked in a non-trivial fashion. We propose possible scenarios to explain this unconventional behavior [1].

[1] Rout P. K., Maniv E. and Dagan Y. (2017). Link between the superconducting dome and spin-orbit interaction in the (111) LaAlO₃/SrTiO₃ interface. arXiv preprint arXiv:1706.01717v2. Accepted in Phys. Rev. Lett.