Coulomb blockade in quantum dots with overlapping resonances

TL;DR

This paper analyzes Coulomb blockade phenomena in quantum dots with overlapping resonances, explaining experimental transmission phase behaviors and illustrating the effects with numerical simulations of non-chaotic quantum dots.

Contribution

It introduces a model for Coulomb blockade in quantum dots with broad and narrow levels, explaining experimental observations and supported by numerical simulations.

Findings

Multiple CB peaks can correspond to occupation of a single broad level.

Transmission at consecutive resonances repeats due to electron jumps between levels.

Numerical simulations show behavior in non-chaotic quantum dots.

Abstract

Coulomb blockade (CB) in a quantum dot (QD) with one anomalously broad level is considered. In this case many consecutive pronounced CB peaks correspond to occupation of one and the same broad level. Between the peaks the electron jumps from this level to one of the narrow levels and the transmission through the dot at the next resonance essentially repeats that at the previous one. This offers a natural explanation to the recently observed behavior of the transmission phase in an interferometer with a QD. Single particle resonances of very different width are natural if the dot is not fully chaotic. This idea is illustrated by the numerical simulations for a non-integrable QD whose classical dynamics is intermediate between integrable and chaotic. Possible manifestations for the Kondo experiments in the QD are discussed.