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.

5pages 3 figures and an appendix ONLY in arXiv version

References in corpus (2)

• Suppression of weak-localization (and enhancement of noise) by tunnelling in semiclassical chaotic transport
• Staggered repulsion of transmission eigenvalues in symmetric open mesoscopic systems

Cited by in corpus (9)

• Transport inefficiency in branched-out mesoscopic networks: An analog of the Braess paradox
• Symmetry-dependent transport behavior of graphene double dots
• Semiclassical transport in nearly symmetric quantum dots I: symmetry-breaking in the dot
• Sinc-based method for an efficient solution in the direct space of quantum wave equations with periodic boundary conditions
• Effect of potential fluctuations on shot noise suppression in mesoscopic cavities
• Semiclassical transport in nearly symmetric quantum dots II: symmetry-breaking due to asymmetric leads
• Experimental evidence of enhanced broadband transmission in disordered systems with mirror symmetry
• Mirror Symmetry in three-dimensional Multiple-Scattering Media
• Disappearance of Quantum Chaos in Coupled Chaotic Quantum Dots