Coulomb Blockade due to Quantum Phase-Slips Illustrated with Devices

TL;DR

This paper proposes and analyzes theoretical superconducting devices, QPS-box and QPS-transistor, demonstrating Coulomb blockade arising from quantum phase-slip coherence, with potential experimental validation of this quantum effect.

Contribution

The paper introduces two novel device models, QPS-box and QPS-transistor, to illustrate Coulomb blockade caused by quantum phase-slip coherence, expanding understanding of superconducting quantum phenomena.

Findings

Devices show charge sensitivity indicating Coulomb blockade.

Six regimes identified based on energy scale relations.

Analysis includes dual Josephson-junction device discussion.

Abstract

In order to illustrate the emergence of Coulomb blockade from coherent quantum phase-slip processes in thin superconducting wires, we propose and theoretically investigate two elementary setups, or "devices". The setups are derived from Cooper-pair box and Cooper-pair transistor, so we refer to them as QPS-box and QPS-transistor, respectively. We demonstrate that the devices exhibit sensitivity to a charge induced by a gate electrode, this being the main signature of Coulomb blockade. Experimental realization of these devices will unambiguously prove the Coulomb blockade as an effect of coherence of phase-slip processes. We analyze the emergence of discrete charging in the limit strong phase-slips. We have found and investigated six distinct regimes that are realized depending on the relation between three characteristic energy scales: inductive and charging energy, and phase-slip amplitude. For completeness, we include a brief discussion of dual Josephson-junction devices.