Observation of Coulomb Blockade Type Conductance Oscillations up to 50 K in Gated InGaAs Ridge Quantum Wires Grown by Molecular Beam Epitaxy on InP Substrates

Abstract

InP-based quantum wire (QWR) transistors were successfully fabricated for the first time directly on InAlAs/InGaAs ridge QWRs grown by selective molecular beam epitaxy (MBE) on patterned (001) InP substrates. Each wire showed strong photoluminescence, cathodoluminescence and Shubnikov-de Haas (SdH) oscillations. The behavior of the SdH oscillations confirmed the presence of gate-controlled one-dimensional transport. Near pinch-off, QWR transistors showed Coulomb blockade type conductance oscillations up to 50 K. The effective value of the Coulomb gap was estimated to be 28 mV. Possible mechanisms for quantum dot formation are discussed.