Single electron capacitance spectroscopy of vertical quantum dots using a single electron transistor

TL;DR

This paper demonstrates the integration of a single electron transistor with a vertical quantum dot to enable highly sensitive charge detection and capacitance measurement, advancing quantum dot electrometry techniques.

Contribution

It introduces a novel method of embedding an SET directly on a quantum dot for precise charge and capacitance measurements, with two effective demodulation techniques.

Findings

Successful integration of SET on quantum dot

Quantitative extraction of single electron capacitance peaks

Two demodulation methods yield consistent results

Abstract

We have incorporated an aluminum single electron transistor (SET) directly on top of a vertical quantum dot, enabling the use of the SET as an electrometer that is extremely responsive to the motion of charge into and out of the dot. Charge induced on the SET central island from single electron additions to the dot modulates the SET output, and we describe two methods for demodulation that permit quantitative extraction of the quantum dot capacitance signal. The two methods produce closely similar results for the determined single electron capacitance peaks.