Optically induced spin to charge transduction in donor spin read-out

TL;DR

This paper proposes an optically induced method for single-spin read-out in donor-based quantum computing, improving measurement fidelity by increasing the D+D- state lifetime through optical transduction.

Contribution

It introduces a novel optical approach for spin to charge transduction, reducing gate bias requirements and enhancing read-out reliability in donor spin qubits.

Findings

Optically induced transduction extends D+D- state lifetime.

Reduced gate bias needed for qubit selection.

Enhanced potential for singlet-triplet spin discrimination.

Abstract

The proposed read-out configuration D+D- for the Kane Si:P architecture[Nature 393, 133 (1998)] depends on spin-dependent electron tunneling between donors, induced adiabatically by surface gates. However, previous work has shown that since the doubly occupied donor state is so shallow the dwell-time of the read-out state is less than the required time for measurement using a single electron transistor (SET). We propose and analyse single-spin read-out using optically induced spin to charge transduction, and show that the top gate biases, required for qubit selection, are significantly less than those demanded by the Kane scheme, thereby increasing the D+D- lifetime. Implications for singlet-triplet discrimination for electron spin qubits are also discussed.