We report on measurements of the magnetoconductance of an open circular InGaAs quantum dot between 1.3K and 204K. We observe two types of magnetoconductance fluctuations: universal conductance fluctuations (UCFs), and 'focusing' fluctuations related to ballistic trajectories between openings. The electron phase coherence time extracted from UCFs amplitude is larger than in GaAs/AlGaAs quantum dots and follows a similar temperature dependence (between T^-1 and T^-2). Below 150K, the characteristic length associated with 'focusing' fluctuations shows a slightly different temperature dependence from that of the conductivity.
@article{arxiv.cond-mat/0210093,
title = {Long dephasing time and high temperature ballistic transport in an InGaAs open quantum dot},
author = {B. Hackens and S. Faniel and F. Delfosse and C. Gustin and H. Boutry and I. Huynen and X. Wallaert and S. Bollaert and A. Cappy and V. Bayot},
journal= {arXiv preprint arXiv:cond-mat/0210093},
year = {2009}
}
Comments
6 pages, 4 figures, proceedings of ICSNN2002, to appear in Physica E