We grow a tiled structure of insulating two-dimensional ${\mathrm{LaAlO}}_3$/${\mathrm{SrTiO}}_3$ interfaces composed of alternating one and three ${\mathrm{LaAlO}}_3$ unit cells. The boundary between two tiles is conducting. At low temperatures this conductance exhibits quantized steps as a function of gate voltage indicative of a one-dimensional channel. The step size of half the quantum of conductance is evidence for the absence of spin degeneracy.

• Received 4 November 2013

DOI:https://doi.org/10.1103/PhysRevLett.112.136801