Imaging a 1-electron InAs quantum dot in an InAs/InP nanowire

TL;DR

This paper demonstrates the use of a cooled scanning probe microscope to image and control a single-electron InAs quantum dot within an InAs/InP nanowire, enabling precise charge manipulation for quantum applications.

Contribution

It introduces a novel method to image and tune a quantum dot in a nanowire using an SPM as a movable gate, advancing control in nanoelectronic devices.

Findings

SPM images show concentric conductance rings indicating electron addition.

The SPM can locate the quantum dot along the nanowire.

The SPM can individually tune the charge state of the quantum dot.

Abstract

Nanowire heterostructures define high-quality few-electron quantum dots for nanoelectronics, spintronics and quantum information processing. We use a cooled scanning probe microscope (SPM) to image and control an InAs quantum dot in an InAs/InP nanowire, using the tip as a movable gate. Images of dot conductance vs. tip position at T = 4.2 K show concentric rings as electrons are added, starting with the first electron. The SPM can locate a dot along a nanowire and individually tune its charge, abilities that will be very useful for the control of coupled nanowire dots.