Coulomb blockade in superconducting quantum point contacts

TL;DR

This paper investigates how Coulomb blockade oscillations behave in superconducting quantum point contacts, showing suppression in highly transparent junctions and modeling it via Landau-Zener transitions in imaginary time.

Contribution

It provides a quantitative analysis of Coulomb blockade suppression in ballistic Josephson junctions with high electron transparency.

Findings

Coulomb blockade oscillations are suppressed in junctions with electron transparency approaching 1.

The suppression mechanism is modeled as a Landau-Zener transition in imaginary time.

The amplitude of Coulomb blockade oscillations depends on the transparency of the junction.

Abstract

Amplitude of the Coulomb blockade oscillations is calculated for a single-mode Josephson junction with arbitrary electron transparency $D$. It is shown that the Coulomb blockade is suppressed in ballistic junctions with $D\to 1$. The suppression is described quantitatively as the Landau-Zener transition in imaginary time.