A fast "hybrid" silicon double quantum dot qubit

TL;DR

This paper introduces a fast, easily fabricated silicon double quantum dot qubit architecture with promising coherence properties for quantum computing.

Contribution

It presents a novel hybrid silicon double quantum dot design that combines speed, fabrication simplicity, and long decoherence times for quantum information processing.

Findings

The proposed qubit architecture enables fast electrical operations.

The design is simple to fabricate using existing technology.

The system potentially exhibits long decoherence times.

Abstract

We propose a quantum dot qubit architecture that has an attractive combination of speed and fabrication simplicity. It consists of a double quantum dot with one electron in one dot and two electrons in the other. The qubit itself is a set of two states with total spin quantum numbers $S^2=3/4$ ($S=\half$) and $S_z = -\half$, with the two different states being singlet and triplet in the doubly occupied dot. The architecture is relatively simple to fabricate, a universal set of fast operations can be implemented electrically, and the system has potentially long decoherence times. These are all extremely attractive properties for use in quantum information processing devices.