Silicon quantum computation based on magnetic dipolar coupling

TL;DR

This paper proposes a silicon-based quantum computing scheme utilizing magnetic dipolar coupling between electron spins, offering a scalable alternative to exchange-based gates with manageable error correction.

Contribution

It introduces a dipolar gate method in silicon quantum computers that relaxes donor placement constraints and maintains scalability without increasing gating time.

Findings

Dipolar coupling enables scalable quantum gates in silicon.

Residual exchange acts as manageable gate error.

The scheme removes strict donor positioning requirements.

Abstract

A dipolar gate alternative to the exchange gate based Kane quantum computer is proposed where the qubits are electron spins of shallow group V donors in silicon. Residual exchange coupling is treated as gate error amenable to quantum error correction, removing the stringent requirements on donor positioning characteristic of all silicon exchange-based implementations [B. Koiller et al., Phys. Rev. Lett. 88, 027903 (2002)]. Contrary to common speculation, such a scheme is scalable with no overhead in gating time even though it is based on long-range dipolar inter-qubit coupling.