A novel quantum wire formed by lateral p–n–p junctions between quasi-two-dimensional electron and hole systems at corrugated GaAs/AlGaAs interfaces

Abstract

Numerical modeling of a novel quantum wire structure formed by the confinement of electrons between lateral quasi‐two‐dimensional (Q2‐D) p–n junctions in a corrugated GaAs/AlGaAs heterostructure is reported on. Such a quantum wire may be realized at the tip of a Si‐doped AlGaAs overgrown V groove in a SI–GaAs substrate due to the surface orientation dependence of Si doping. The two‐dimensional conduction and valence band potential profiles for the electron and hole charge densities are solved within a semiclassical Thomas–Fermi screening model. The quantized electronic wire states at the heterointerface are then obtained by solving the two‐dimensional effective mass Schrödinger equation using the calculated potential profile. The parameter space of the one‐dimensional electron system is explored to establish which features of the structure are dominant factors in controlling the electronic states. It is demonstrated that the energy level spacing of the quantum wire depends primarily on the lateral confinement width in the n‐type region at the tip of the V groove. The ground state energy of the wire is shown to depend on both the lateral confinement width and the vertical heterointerface confinement width. The results of our initial calculations are also reported on to incorporate lateral gates on the surface to obtain direct control of the quantum wire transport properties. The advantages of fabricating quantum wires with this structure compared to conventional methods of electrostatic confinement are discussed.