Coulomb Blockade in a Silicon/Silicon-Germanium Two-Dimensional Electron Gas Quantum Dot

TL;DR

This paper demonstrates the fabrication and electrical characterization of a silicon/silicon-germanium quantum dot single electron transistor, revealing Coulomb blockade effects and quantifying the electron charging energy at low temperatures.

Contribution

It introduces a novel fabrication method for silicon/silicon-germanium quantum dots with tunable potentials using electron beam lithography and reactive ion etching.

Findings

Coulomb blockade observed with a 3.2 meV charging energy

Quantum dot controlled by lateral side gates

Successful fabrication of a silicon/silicon-germanium single electron transistor

Abstract

We report the fabrication and electrical characterization of a single electron transistor in a modulation doped silicon/silicon-germanium heterostructure. The quantum dot is fabricated by electron beam lithography and subsequent reactive ion etching. The dot potential and electron density are modified by laterally defined side gates in the plane of the dot. Low temperature measurements show Coulomb blockade with a single electron charging energy of 3.2 meV.