Temperature dependent deviations from ideal quantization of plateau conductances in GaAs quantum point contacts

A. E. Hansen, A. Kristensen, H. Bruus

Published 2002-08-23Version 1

We present detailed experimental studies of the temperature dependence of the plateau conductance of GaAs quantum point contacts in the temperature range from 0.3 K to 10 K. Due to a strong lateral confinement produced by a shallow-etching technique we are able to observe the following unexpected feature: a linear temperature dependence of the measured mid-plateau conductance. We discuss an interpretation in terms of a temperature dependent, intrinsic series resistance, due to non-ballistic effects in the 2D-1D transition region. These results have been reproduced in several samples from different GaAs/GaAlAs heterostructures and observed in different experimental set-ups.