Entanglement of dark electron-nuclear spin defects in diamond

M J Degen,A L Meinsma,M Markham,D J Twitchen,T H Taminiau,H P Bartling,C E Bradley,S J H Loenen

doi:10.1038/s41467-021-23454-9

M J Degen, A L Meinsma + Show 6 more

Open Access

https://doi.org/10.1038/s41467-021-23454-9

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Abstract

A promising approach for multi-qubit quantum registers is to use optically addressable spins to control multiple dark electron-spin defects in the environment. While recent experiments have observed signatures of coherent interactions with such dark spins, it is an open challenge to realize the individual control required for quantum information processing. Here, we demonstrate the heralded initialisation, control and entanglement of individual dark spins associated to multiple P1 centers, which are part of a spin bath surrounding a nitrogen-vacancy center in diamond. We realize projective measurements to prepare the multiple degrees of freedom of P1 centers—their Jahn-Teller axis, nuclear spin and charge state—and exploit these to selectively access multiple P1s in the bath. We develop control and single-shot readout of the nuclear and electron spin, and use this to demonstrate an entangled state of two P1 centers. These results provide a proof-of-principle towards using dark electron-nuclear spin defects as qubits for quantum sensing, computation and networks.

Highlights

A promising approach for multi-qubit quantum registers is to use optically addressable spins to control multiple dark electron-spin defects in the environment
Underlying our selective control of individual centers is the heralded preparation of specific configurations of these additional degrees of freedom for multiple P1 centers through projective measurements
We consider a bath of P1 centers surrounding a single NV center at 3.3 K (Fig. 1a)

Summary

Introduction

A promising approach for multi-qubit quantum registers is to use optically addressable spins to control multiple dark electron-spin defects in the environment. We develop control and singleshot readout of the nuclear and electron spin, and use this to demonstrate an entangled state of two P1 centers. These results provide a proof-of-principle towards using dark electronnuclear spin defects as qubits for quantum sensing, computation and networks. All previous experiments averaged over these additional degrees of freedom[41,42,53] We use this capability to develop initialization, single-shot readout, and control of the electron and nuclear spin states of multiple P1s, and investigate their spin relaxation and coherence times. We demonstrate the potential of these dark spins as a qubit platform by realizing an entangled state between two P1 electron spins through their direct magnetic–dipole coupling

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