We predict a huge interference effect contributing to the conductance through large ultraclean 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.
|Autori:||Whitney RS; Marconcini P; Macucci M|
|Titolo:||Huge Conductance Peak Caused by Symmetry in Double Quantum Dots|
|Anno del prodotto:||2009|
|Digital Object Identifier (DOI):||10.1103/PhysRevLett.102.186802|
|Appare nelle tipologie:||1.1 Articolo in rivista|