Symmetry causes a huge conductance peak in double quantum dots

Autor: Whitney, Robert S., Marconcini, P., Macucci, M.
Rok vydání: 2009
Předmět:
Zdroj: R. S. Whitney, P. Marconcini, M. Macucci, "Huge conductance peak caused by symmetry in double quantum dots", Phys. Rev. Lett. 102, 186802 (2009)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevLett.102.186802
Popis: 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.
Comment: 5pages 3 figures and an appendix ONLY in arXiv version
Databáze: arXiv