High-frequency single-electron transport and the quantized acoustoelectriceffect

A quantized current may be induced through a one-dimensional channel by a s trong surface acoustic wave. Such devices offer a possible route towards a current standard, with the high induced current being suitable for metrolog ical applications. We report on new observations of quantized charge transp ort in etched constrictions. Plateaux hat to a precision of around +/- 50 p arts per million are compared to results obtained in Schottky gated samples . The influence of a perpendicular magnetic field on the quantization is di scussed for the first time. (C) 2000 Elsevier Science B.V. All rights reser ved.