Coulomb Charging at Large Conduction

TL;DR

This paper investigates how quantum fluctuations at low temperatures reduce Coulomb charging effects in metallic islands with high tunneling conductance, providing explicit calculations of the effective charging energy.

Contribution

It offers a detailed analysis of Coulomb charging suppression due to quantum fluctuations, especially in the regime of large tunneling conductance, extending classical models.

Findings

Quantum corrections to charging energy are significant at high temperatures.

Large quantum fluctuations reduce the effective Coulomb energy at low temperatures.

Explicit expressions for the effective charging energy are derived in the high conductance limit.

Abstract

We discuss the suppression of Coulomb charging effects on a small metallic island coupled to an electrode by a tunnel junction. At high temperatures the quantum corrections to the classical charging energy $E_c=e^2/2C$, where $C$ is the island capacitance, are evaluated. At low temperatures the large quantum fluctuations of the island charge cause a strong reduction of the effective $E_c$ which is determined explicitly in the limit of a large tunneling conductance.