Contact dimension effects in the conductance of semiconductor nanowires

• Published in: Journal of superconductivity Vol. 18; no. 3; pp. 375 - 377
• Main Authors: DACAL, Luis C. O, DE ANDRADA E SILVA, Erasmo A
• Format: Conference Proceeding Journal Article
• Language: English
• Published: New York, NY Kluwer/Plenum 01.06.2005
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Quantum wires; Confinement; Dimensionality; Electrical conductivity; Semiconductor materials; semiconductor nanowires; Envelope function; Oscillations; Ballistic transport; Quasibound states; quantum ballistic transport; Size effect; conductance oscillations; Schroedinger equation; Nanowires; Quantum transport
• ISSN: 0896-1107; 1572-9605
• DOI: 10.1007/S10948-005-0013-2

With the exact solution of the Schroedinger equation for electrons in three-dimensional (3D) hardwall quantum channels, the conductance of small and short semiconductor quantum wires, or nanowires, is studied as a function of length, size, and contact dimensionality. Within the envelope function approximation, the two-terminal Landauer-Buttiker conductance has been calculated in the quantum ballistic regime, with complete mode mixing at the two end interfaces with the contacts. These are modeled by semi-infinite regions with hardwall confinement along only one of the transverse directions, so that continuous crossover from quasi-2D to 3D contacts can be simulated with increasing confinement length. The conductance oscillations within the 2e /h quantized conductance plateaus, due to the resonant transmission through quasi-bound longitudinal states, are shown to increase with contact dimension.