Imaging a Single-Electron Quantum Dot

TL;DR

This paper demonstrates imaging of a single-electron quantum dot using a cooled scanning probe microscope, revealing how the tip influences electron energy states and enabling potential quantum information applications.

Contribution

It presents the first direct imaging of a single-electron quantum dot in the Coulomb blockade regime at liquid helium temperatures.

Findings

Imaged a quantum dot with a scanning probe microscope.

Observed ring-shaped conductance peaks related to electron energy shifts.

Quantified the tip-induced energy level shifts.

Abstract

Images of a single-electron quantum dot were obtained in the Coulomb blockade regime at liquid He temperatures using a cooled scanning probe microscope (SPM). The charged SPM tip shifts the lowest energy level in the dot and creates a ring in the image corresponding to a peak in the Coulomb-blockade conductance. Fits to the lineshape of the ring determine the tip-induced shift of the electron energy state in the dot. SPM manipulation of electrons in quantum dots promises to be useful in understanding, building and manipulating circuits for quantum information processing.