Novel cleaved edge overgrowth structures for tunneling into one- and two-dimensional electron systems

We report the fabrication of novel electron in-plane tunneling systems in GaAs/Al_xGa_1-xAs using the technique of cleaved edge overgrowth, and report results of tunneling measurements into both one- and two-dimensional (1D and 2D) systems. Our devices demonstrate tunneling through an abrupt molecular beam epitaxially defined barrier where the shape of the barrier potential is exactly known. We study three different in-plane tunneling geometries, namely 2D-1D-2D, 2D-2D and 2D-3D, and report current vs voltage characteristics for all three geometries.