One-Dimensional Nature of Superconductivity at the LaAlO3/SrTiO3 Interface

We examine superconductivity in LaAlO3/SrTiO3 channels with widths that transition from the 1D to the 2D regime. The superconducting critical current is independent of the channel width and increases approximately linearly with the number of parallel channels. Signatures of electron pairing outside of the superconducting regime are also found to be independent of the channel width. Collectively, these results indicate that superconductivity exists at the boundary of these channels and is absent within the interior region of the channels. The intrinsic 1D nature of superconductivity at the LaAlO3/SrTiO3 interface imposes strong physical constraints on possible electron pairing mechanisms.