Gate-Voltage Studies of Discrete Electronic States in Al Nanoparticles

TL;DR

This study explores the discrete electronic states in aluminum nanoparticles using gate-controlled tunneling transistors, revealing new insights into spectra resolution, superconducting states, and non-equilibrium effects.

Contribution

It introduces a novel experimental setup with a gate electrode enabling detailed spectral analysis and non-equilibrium studies of aluminum nanoparticles.

Findings

Enhanced spectral resolution with gating

Observation of superconducting state spectra

Demonstration of non-equilibrium excitation effects

Abstract

We have investigated the spectrum of discrete electronic states in single, nm-scale Al particles incorporated into new tunneling transistors, complete with a gate electrode. The addition of the gate has allowed (a) measurements of the electronic spectra for different numbers of electrons in the same particle, (b) greatly improved resolution and qualitatively new results for spectra within superconducting particles, and (c) detailed studies of the gate-voltage dependence of the resonance level widths, which have directly demonstrated the effects of non-equilibrium excitations.