Out-of-Equilibrium Admittance of Single Electron Box Under Strong Coulomb Blockade

TL;DR

This paper investigates the admittance and energy dissipation in a single electron box under strong Coulomb blockade, revealing how charge relaxation resistance and renormalized capacitance describe out-of-equilibrium behavior.

Contribution

It provides a theoretical analysis of admittance in a non-equilibrium single electron box considering quantum fluctuations and Coulomb interactions, introducing a method to measure collective excitations.

Findings

Energy dissipation relates to charge relaxation resistance and renormalized capacitance.

Admittance can serve as a tool to measure collective excitations.

Out-of-equilibrium conditions do not alter the fundamental admittance expressions.

Abstract

We study admittance and energy dissipation in an out-of-equlibrium single electron box. The system consists of a small metallic island coupled to a massive reservoir via single tunneling junction. The potential of electrons in the island is controlled by an additional gate electrode. The energy dissipation is caused by an AC gate voltage. The case of a strong Coulomb blockade is considered. We focus on the regime when electron coherence can be neglected but quantum fluctuations of charge are strong due to Coulomb interaction. We obtain the admittance under the specified conditions. It turns out that the energy dissipation rate can be expressed via charge relaxation resistance and renormalized gate capacitance even out of equilibrium. We suggest the admittance as a tool for a measurement of the bosonic distribution corresponding collective excitations in the system.