Electrostatic potential and quantum transport in a one-dimensional channel of an induced two-dimensional electron gas

摘要

We discuss quantization of the conductance in short, ultraclean one-dimensional quantum wires of a design where an electron gas is induced electrostatically. Two-level sets of gates allow independent control of electron density in the constriction and in the reservoirs, thus varying the conductance G as a function of the bias on the gates G(V-tg,V-sg). Up to 12 clean well-resolved conductance G(V-sg) plateaus confirm the high quality of the constriction. The experimental curves are modeled using three-dimensional self-consistent calculations in the Thomas-Fermi approximation of the electrostatic potential of the constriction and solution of the two-dimensional problem of electron transport in the calculated potential. Our calculations are in qualitative agreement with the experiment. (C) 2001 American Institute of Physics. References: 18