Correlations in the cotunneling regime of a quantum dot

TL;DR

This paper investigates conductance correlations in quantum dots in the cotunneling regime, showing theoretical predictions within the constant interaction model and discussing discrepancies with experimental results due to model limitations.

Contribution

It provides a theoretical analysis of valley conductance correlations in quantum dots and highlights the limitations of the constant interaction model in explaining experimental observations.

Findings

Significant valley-valley conductance correlations are predicted theoretically.

Experimental correlations are less robust than the model predicts.

Breakdown of the constant interaction model may explain discrepancies.

Abstract

Off-resonance conductance through weakly coupled quantum dots ("valley conductance") is governed by cotunneling processes in which a large number of dot states participate. Virtually the same states participate in the transport at consecutive valleys, which leads to significant valley-valley conductance correlations. These correlations are calculated within the constant interaction model. Comparison with experiment shows that these correlations are less robust in reality. Among the possible reasons for this is the breakdown of the constant interaction model, accompanied by "scrambling" of the dot as the particle number is varied.