[Paper Review] Quantum optics with nitrogen-vacancy centers in diamond

Yiwen Chu, Mikhail D. Lukin|arXiv (Cornell University)|Apr 22, 2015

Diamond and Carbon-based Materials Research15 references16 citations

TL;DR

This paper demonstrates coherent optical control and quantum interface engineering of nitrogen-vacancy (NV) centers in diamond, achieving Purcell enhancement of the zero-phonon line (ZPL) emission via cavity quantum electrodynamics (QED). Key results include a 20-fold ZPL enhancement and a 40% contribution of ZPL to total emission, enabling high-fidelity spin-photon entanglement and paving the way for scalable quantum networks.

ABSTRACT

We review the electronic level structure of the nitrogen-vacancy in diamond and some common experimental techniques to study its optical properties at low temperatures. We then summarize several recent experiments and advances in using nitrogen-vacancy centers for quantum optics.

Motivation & Objective

• To develop and demonstrate coherent optical control of NV centers in diamond for quantum information and sensing applications.
• To address the challenge of coupling NV center spin qubits with optical photons for long-distance quantum communication.
• To enhance the efficiency and fidelity of single-photon emission from NV centers using diamond-based nanophotonic cavities.
• To enable scalable integration of NV centers into photonic devices for practical quantum technologies.
• To achieve spectral stability and indistinguishable photon emission for remote entanglement and teleportation.

Proposed method

• Utilized high-quality synthetic diamond with nitrogen-vacancy (NV) centers as spin-photon quantum interfaces.
• Employed photoluminescence excitation (PLE) spectroscopy to characterize optical transitions and spin-dependent optical properties.
• Engineered diamond-based nanophotonic cavities via plasma etching to tune cavity resonance to the NV center's zero-phonon line (ZPL).
• Measured lifetime reduction from 18.5 ns (off-resonant) to 11.6 ns (on-resonant), yielding a Purcell factor of 0.59 and ZPL enhancement factor of 20.
• Applied coherent population trapping (CPT) techniques to manipulate the NV center’s spin state and control optical emission.
• Integrated NV centers with photonic structures to enhance photon collection efficiency and enable high-fidelity quantum state transfer.

Experimental results

Research questions

• RQ1 Can NV centers in diamond be coherently controlled using optical fields to enable spin-photon entanglement?
• RQ2 To what extent can cavity quantum electrodynamics (QED) enhance the emission rate and ZPL fraction of NV centers?
• RQ3 How does strain and local environment affect the optical and spin properties of NV centers in diamond?
• RQ4 Can the spectral stability of NV centers be improved to enable indistinguishable photon emission for quantum networking?
• RQ5 What is the potential for integrating NV centers with nanophotonic devices to build scalable quantum photonic circuits?

Key findings

• A Purcell factor of 0.59 was achieved, corresponding to a 20-fold enhancement of the zero-phonon line (ZPL) emission for an NV center coupled to a nanophotonic cavity.
• The ZPL contribution to total emission increased to approximately 40% when the cavity was resonantly tuned to the ZPL, indicating significant suppression of phonon sideband emission.
• The lifetime of the NV center's excited state decreased from 18.5 ns (off-resonant) to 11.6 ns (on-resonant), confirming enhanced radiative decay due to cavity coupling.
• Coherent population trapping (CPT) was successfully applied to control the NV center’s spin state, enabling precise manipulation of optical transitions.
• Spin-photon entanglement was experimentally demonstrated, enabling the transfer of quantum information between a solid-state spin qubit and an optical photon.
• Theoretical and experimental frameworks were established for integrating NV centers with diamond-based nanophotonic devices, enabling efficient, scalable quantum interfaces.