Electron transport in AlGaAs/GaAs V-groove quantum wires

We fabricated modulation doped GaAs-AlGaAs V-groove heterostructures incorp orating quantum wires (QWRs), using organometallic chemical vapor depositio n on corrugated substrates. Electron-beam lithography was employed to isola te a single QWR and to apply Schottky gates to the QWR and to the V-groove sidewalls. We observed a two-step sequence of carrier depletion, first from the sidewalls and then from the QWR, when a progressively more negative ga te voltage was applied. In the regime of QWR depletion the conductance decr eases in steps which attain 90% of the quantized value 2e(2)/h. (C) 1999 El sevier Science B.V. All rights reserved.