Single-dot spectroscopy via elastic single-electron tunneling through a pair of coupled quantum dots

TL;DR

This paper investigates the electronic structure of a single InAs quantum dot by analyzing elastic single-electron tunneling through a coupled dot pair, revealing shell addition spectra and Fock-Darwin spectra.

Contribution

It introduces a method to probe the electronic shell structure of a single quantum dot using elastic tunneling through coupled dots, providing detailed spectral information.

Findings

Identified s and p shell addition spectra for up to six electrons.

Demonstrated the evolution of shell spectra with magnetic field.

Revealed Fock-Darwin spectra for the quantum dot shells.

Abstract

We study the electronic structure of a single self-assembled InAs quantum dot by probing elastic single-electron tunneling through a single pair of weakly coupled dots. In the region below pinch-off voltage, the non-linear threshold voltage behavior provides electronic addition energies exactly as the linear, Coulomb blockade oscillation does. By analyzing it, we identify the s and p shell addition spectrum for up to six electrons in the single InAs dot, i.e. one of the coupled dots. The evolution of shell addition spectrum with magnetic field provides Fock-Darwin spectra of s and p shell.