High fidelity optical readout of a nuclear spin qubit in Silicon Carbide

TL;DR

This paper demonstrates a high fidelity, efficient optical readout of a nuclear spin qubit in Silicon Carbide, enabling quantum memory and sensing applications with fidelity up to 99.5%.

Contribution

It introduces a repetitive readout technique achieving near-perfect fidelity for nuclear spin qubits in Silicon Carbide, advancing quantum information processing.

Findings

Achieved 99.5% readout fidelity.

Demonstrated nuclear spin initialization and coherent control.

Applied nuclear spin as a quantum sensor for weakly coupled nuclear spins.

Abstract

Quantum state readout is a key requirement for a successful qubit platform. In this work we demonstrate a high fidelity quantum state readout of a V2 center nuclear spin based on a repetitive readout technique. We demonstrate up to 99.5$\,\%$ readout fidelity and 99$\,\%$ for state preparation. Using this efficient readout we initialise the nuclear spin by measurement and demonstrate its Rabi and Ramsey nutation. Finally, we use the nuclear spin as a long lived memory for quantum sensing application of weakly coupled diatomic nuclear spin bath.