Fabrication and characterization of electrostatic Si∕SiGe quantum dots with an integrated read-out channel

Abstract

A nontraditional fabrication technique is used to produce quantum dots with read-out channels in silicon/silicon–germanium two-dimensional electron gases. The technique utilizes Schottky gates, placed on the sides of a shallow etched quantum dot, to control the electronic transport process. An adjacent quantum point contact gate is integrated to the side gates to define a read-out channel, and thus allow for noninvasive detection of the electronic occupation of the quantum dot. Reproducible and stable Coulomb oscillations and the corresponding jumps in the read-out channel resistance are observed at low temperatures. The fabricated dot combined with the read-out channel represents a step toward the spin-based quantum bit in Si∕SiGe heterostructures.