December 22, 2024

Cavity-assisted resonance fluorescence from a nitrogen-vacancy center in diamond

Cavity-assisted resonance fluorescence from a nitrogen-vacancy center in diamond

npj Quantum Information, Published online: 07 November 2024; doi:10.1038/s41534-024-00915-9

Cavity-assisted resonance fluorescence from a nitrogen-vacancy center in diamond

The nitrogen-vacancy center in diamond is an attractive resource for the generation of remote entangled states owing to its optically addressable and long-lived electronic spin.

However, its low native fraction of coherent photon emission, ~3%, undermines the achievable spin-photon entanglement rates.

In this paper, the researchers have coupled a nitrogen-vacancy center with a narrow extrinsically-broadened linewidth (159 MHz), hosted in a micron-thin membrane, to an open microcavity.

The resulting Purcell factor of ~1.8 increases the zero-phonon line fraction to over 44%. Operation in the Purcell regime, together with an efficient collection of the zero-phonon-line photons, allows resonance fluorescence to be detected for the first time without any temporal filtering.

They have achieve a >10 signal-to-laser background ratio. This selective enhancement of the center’s zero-phonon transitions could increase spin-spin entanglement success probabilities beyond an order of magnitude compared to state-of-the-art implementations, and enable powerful quantum optics techniques such as wave-packet shaping or all-optical spin manipulation.