Tunnelling density of states at Coulomb blockade peaks

TL;DR

This paper calculates the tunnelling density of states in a quantum dot under Coulomb blockade, revealing a suppression at peaks that is essential for accurate conductance predictions.

Contribution

It introduces a functional integral approach that correctly accounts for charge quantisation, revealing new features of the TDoS at Coulomb blockade peaks.

Findings

Suppression of TDoS at Coulomb blockade peaks.

Confirmation of a gap in TDoS in Coulomb-blockade valleys.

Necessary suppression for accurate conductance peak modeling.

Abstract

We calculate the tunnelling density of states (TDoS) for a quantum dot in the Coulomb blockade regime, using a functional integral representation with allowing correctly for the charge quantisation. We show that in addition to the well-known gap in the TDoS in the Coulomb-blockade valleys, there is a suppression of the TDoS at the peaks. We show that such a suppression is necessary in order to get the correct result for the peak of the differential conductance through an almost close quantum dot.