Symmetry causes a huge conductance peak in double quantum dots
Abstract
We predict a huge interference effect contributing to the conductance through large ultra-clean quantum dots of chaotic shape. When a double-dot structure is made such that the dots are the mirror-image of each other, constructive interference can make a tunnel barrier located on the symmetry axis effectively transparent. We show (via theoretical analysis and numerical simulation) that this effect can be orders of magnitude larger than the well-known universal conductance fluctuations and weak-localization (both less than a conductance quantum). A small magnetic field destroys the effect, massively reducing the double-dot conductance; thus a magnetic field detector is obtained, with a similar sensitivity to a SQUID, but requiring no superconductors.
Keywords
Cite
@article{arxiv.0902.3099,
title = {Symmetry causes a huge conductance peak in double quantum dots},
author = {Robert S. Whitney and P. Marconcini and M. Macucci},
journal= {arXiv preprint arXiv:0902.3099},
year = {2013}
}
Comments
5pages 3 figures and an appendix ONLY in arXiv version