Conductance Fluctuations in a Disordered Double-Barrier Junction

Abstract

We consider the effect of disorder on coherent tunneling through two barriers in series, in the regime of overlapping transmission resonances. We present analytical calculations (using random-matrix theory) and numerical simulations (on a lattice) to show that strong mode-mixing in the inter-barrier region induces mesoscopic fluctuations in the conductance $G$ of universal magnitude $e^2/h$ for a symmetric junction. For an asymmetric junction, the root-mean-square fluctuations depend on the ratio $\nu$ of the two tunnel resistances according to $rmsG=(4e^2/h){\beta }^{-1/2}\nu (1+\nu {)}^{-2}$, where $\beta =1(2)$ in the presence (absence) of time-reversal symmetry.

12 pages, REVTeX-3.0, 2 figures, submitted to Physical Review B

References in corpus (5)

• Mesoscopic Transport Through Ballistic Cavities: A Random S-Matrix Theory Approach
• Universal Quantum Signatures of Chaos in Ballistic Transport
• Reflectionless Tunneling Through a Double-Barrier NS Junction
• Conductance Fluctuations, Weak Localization, and Shot Noise for a Ballistic Constriction in a Disordered Wire
• Global fluctuation formulas and universal correlations for random matrices and log-gas systems at infinite density

Cited by in corpus (5)

• Random-Matrix Theory of Quantum Transport
• Super-Radiant Dynamics, Doorways, and Resonances in Nuclei and Other Open Mesoscopic Systems
• Transport Through Nanostructures with Asymmetric Coupling to the Leads
• Mesoscopic conductance fluctuations in InAs nanowire-based SNS junctions
• Mesoscopic fluctuations of the supercurrent in diffusive Josephson junctions