Inhomogeneous electron gas at oxide interfaces with strong Rashba spin-orbit coupling

The 2D electron gas (2DEG) formed at the LaXO3/SrTiO3 (X 1⁄4 Al, Ti) oxide interface appears inhomogeneous in several experiments. In particular, we discuss evidences of electron inhomo- geneities provided by the phenomenology of the superconducting (SC) phase, which occurs when the carrier density is tuned above a critical value by means of gating, and of the superconductor- to-metal transition driven by gate voltage or magnetic ̄eld. The measured resistance and super°uid density result from the percolative connection of superconducting puddles" with randomly distributed critical temperatures, embedded in a weakly localizing metallic matrix. We propose a possible intrinsic origin of the electron inhomogeneity, resulting from the strong Rashba spin–orbit coupling (RSOC) measured at these oxide interfaces.