Mesoscopic Fluctuations of Elastic Cotunneling

TL;DR

This paper investigates mesoscopic conductance fluctuations in quantum dots during elastic cotunneling, revealing universal behavior and a crossover between symmetry classes influenced by magnetic fields and charging energy.

Contribution

It provides an analytical description of conductance fluctuations, including the magnetic correlation field and the universal form of the correlation function, highlighting the crossover between orthogonal and unitary ensembles.

Findings

Conductance fluctuations are strongly affected by magnetic fields.

The magnetic correlation field depends on the charging energy.

The correlation function exhibits a universal form with a crossover between ensembles.

Abstract

We study mesoscopic fluctuations of the conductance through a quantum dot at the wings of the Coulomb blokade peaks. At low temperatures, the main mechanism of conduction is the elastic cotunneling. The conductance strongly fluctuates with an applied magnetic field. The magnetic correlation field is shown to be controlled by the charging energy, and the correlation function has a universal form. The distribution function for the conductance obtained analytically shows a non-trivial crossover between the orthogonal and unitary ensembles.