Strong Tunneling in the Single-Electron Box

TL;DR

This paper investigates strong tunneling effects in a single-electron box with many modes at zero temperature, introducing a novel renormalization group method that captures charge states without energy cutoffs.

Contribution

A new renormalization group approach that includes all charge states and extends analysis beyond previous perturbative and numerical methods.

Findings

Determined ground-state energy and average charge in strong tunneling regime.

Identified conditions where Coulomb blockade becomes unobservable.

Extended the parameter range for analyzing single-electron devices.

Abstract

We study strong tunneling (i.e. transmission $h/e^2R_T \gg 1$) in the single-electron box with many transverse modes at zero temperature. We develop a new renormalization group method which includes all charge states and requires no initial or final energy cutoff. We determine the ground-state energy, the average charge and the renormalized charging energy. The covered range for the coupling constant and the gate voltage is much increased in comparison to recent perturbative approaches, poor man scaling methods and Quantum Monte Carlo simulations. We reach the regime where Coulomb blockade become practically unobservable.