Interaction of a heralded single photon with nitrogen-vacancy centers in a diamond

At a Glance

Metadata	Details
Publication Date	2020-12-15
Journal	Optics Express
Authors	Maria Gieysztor, Marta Misiaszek, Joscelyn van der Veen, Wojciech Gawlik, Fedor Jelezko
Citations	3
Analysis	Full AI Review Included

Executive Summary

Core Innovation: Demonstrated a simple, room-temperature, cavity- and vacuum-free interface for single-photon/matter interaction using Nitrogen-Vacancy (NV) centers in diamond.
Spectral Mismatch Solution: The experiment successfully utilized the broad absorption spectrum associated with the phonon sideband of NV centers, solving the critical mismatch between narrow atomic transitions and broadband quantum light sources.
Source Quality: The heralded single-photon source (HSPS), based on Spontaneous Parametric Down Conversion (SPDC), exhibited high quality, with the correlation function g⁽²⁾(0) measured as low as 0.0011(2).
Performance Improvement: The heralding scheme significantly improved the Signal-to-Noise Ratio (SNR) by rejecting dark counts, increasing the SNR from 0.65(46) (unheralded) to 4.3(8) (heralded, high power setting).
Material Used: The interaction was performed on a high-concentration (approx. 18 ppm) HPHT diamond sample containing negatively charged NV centers.
Decay Dynamics: Fitted radiative decay times (TR) were measured to be approximately 7.17-7.68 ns, while non-radiative decay times (TN) were around 107-112 ps.
Future Potential: The technique is scalable and applicable to quantum microscopy, quantum illumination, and virtual-state spectroscopy, potentially extending to low NV concentration samples for single color center addressing.

Technical Specifications

Parameter	Value	Unit	Context
Operating Environment	Room	Temperature	Cavity- and vacuum-free interface
NV Center Concentration	~18	ppm	HPHT Diamond Sample
HSPS Tunability Range	452 - 575	nm	SPDC source spectral range
Excitation Wavelength	532	nm	Wavelength chosen for experiment
HSPS FWHM (575 nm)	4	nm	Corresponds to 3.2 THz bandwidth
HSPS g⁽²⁾(0) (Low Power)	0.0011(2)	Dimensionless	Quality of single-photon state
Heralded Photon Rate (High Power)	40	kcps	Count rate of visible photons
Radiative Decay Time (TR, High Power)	7.68(23)	ns	Fitted fluorescence lifetime
Non-Radiative Decay Time (TN, High Power)	107(14)	ps	Fitted fluorescence lifetime
Fluorescence Detection Range	700 - 800	nm	Filtered range for NV^- emission
Observed Conversion Efficiency (Low Power)	1.01(25) x 10^-5	Dimensionless	NV fluorescence photon output per heralded photon input
SNR (Heralded, High Power)	4.3(8)	Dimensionless	Signal-to-Noise Ratio improvement
SPDC Pump Pulse Duration	140	fs	Time duration of laser pulses
SPDC Repetition Period (t₀)	12.5	ns	Time between laser pulses

Key Methodologies

Pump Generation: A red laser beam is frequency doubled, producing a blue pump photon beam incident on a BiBO crystal.
Heralded Single Photon Source (HSPS): The blue pump photon undergoes Type-II SPDC in a PPKTP crystal, generating a pair of photons: one visible (signal) and one infrared (IR, idler).
Heralding and Timing: The IR photon is detected by a Superconducting Single Photon Detector (SSPD), which defines the time reference and heralds the existence of the visible photon.
Excitation Setup: The heralded visible photon (532 nm) is delivered to a custom confocal microscope (CM), reflected by a dichroic mirror (DM), and focused onto the HPHT diamond sample using a microscope objective (MO).
Non-Resonant Absorption: The NV center absorbs the heralded photon via the broad vibronic (phonon) sideband, enabling efficient non-resonant excitation despite the broadband nature of the quantum light.
Fluorescence Collection: The resulting red fluorescence photon (600-800 nm) is collected by the same MO. Filtering optics (DM3 and F3) restrict the detection range to above 700 nm, isolating the NV^- emission.
Time-Resolved Detection: The arrival time of the fluorescence photon is measured by a Single-Photon Avalanche Diode (SPAD) relative to the SSPD herald signal, generating a histogram of arrival times used to fit the fluorescence decay model (including radiative TR and non-radiative TN components).

Commercial Applications

Quantum Sensing and Metrology: The robust, room-temperature operation of the NV-diamond system, combined with high-quality single-photon input, is ideal for developing scalable quantum sensors (e.g., magnetometers, thermometers).
Quantum Network Infrastructure: Provides a viable, solid-state platform for quantum memories and quantum repeaters, crucial for long-distance secure quantum communication networks.
Advanced Microscopy: Enables next-generation imaging techniques, including quantum illumination and entangled two-photon absorption microscopy, offering enhanced signal-to-noise ratios and potentially lower phototoxicity compared to classical methods.
Spectroscopy and Materials Characterization: The ability to control the statistics of interacting quantum light allows for novel virtual-state spectroscopy, facilitating the study of fundamental properties of atomic systems and color centers.
Solid-State Emitter Development: The methodology is directly transferable to other spectrally broad color centers (e.g., SiV, GeV, SiC), accelerating the characterization and development of new solid-state quantum emitters.

View Original Abstract

A simple, room-temperature, cavity- and vacuum-free interface for a photon-matter interaction is implemented. In the experiment, a heralded single photon generated by the process of spontaneous parametric down-conversion is absorbed by an ensemble of nitrogen-vacancy color centers. The broad absorption spectrum associated with the phonon sideband solves the mismatch problem of a narrow absorption bandwidth in a typical atomic medium and broadband spectrum of quantum light. The heralded single photon source is tunable in the spectral range 452 − 575 nm, which overlaps well with the absorption spectrum of nitrogen-vacancy centers.

Tech Support

Original Source

DOI: https://doi.org/10.1364/oe.409882