Interaction of a heralded single photon with nitrogen-vacancy centers in a diamond
At a Glance
Section titled âAt a Glanceâ| 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 |
Technical Documentation & Analysis: Heralded Single Photon Interaction with NV Centers
Section titled âTechnical Documentation & Analysis: Heralded Single Photon Interaction with NV CentersâThis document analyzes the research paper âInteraction of a heralded single photon with nitrogen-vacancy centers in diamondâ and outlines how 6CCVDâs advanced MPCVD diamond materials and customization capabilities can support, replicate, and extend this critical quantum research.
Executive Summary
Section titled âExecutive SummaryâThe research successfully demonstrated a simple, room-temperature, cavity-free interface for single-photon/matter interaction using Nitrogen-Vacancy (NV) centers in diamond.
- Spectral Mismatch Solution: The broad absorption spectrum associated with the NV phonon sideband was utilized to overcome the spectral mismatch between narrow atomic transitions and broadband quantum light sources.
- Material Used: High-Pressure High-Temperature (HPHT) diamond with a dense concentration of negatively charged NV centers (approximately 18 ppm) was employed.
- Single-Photon Quality: The heralded single-photon source (HSPS) exhibited high quality, verified by a correlation function $g^{(2)}(0)$ as low as 0.0011(2) at lower pump power.
- Observed Dynamics: Fluorescence decay measurements yielded radiative decay times ($\tau_R$) around 7.68 ns (higher power setting), shorter than literature values, attributed to Förster Resonance Energy Transfer (FRET) due to the high NV density.
- Future Requirement: The paper explicitly notes that future work, especially addressing single color centers or cryogenic experiments, requires low NV concentration samples, which are best achieved using high-purity MPCVD diamond.
- 6CCVD Value Proposition: 6CCVD specializes in high-purity Single Crystal Diamond (SCD) and custom fabrication, providing the ideal platform for controlled NV creation and integration into advanced quantum systems.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Diamond Type | HPHT | N/A | Used in experiment (dense NV concentration) |
| NV Concentration | ~18 | ppm | Dense ensemble |
| Excitation Wavelength | 532 | nm | Chosen single-photon wavelength |
| Fluorescence Range | 600 - 800 | nm | NV emission spectrum |
| HSPS Tunable Range | 452 - 575 | nm | Spectral range of the heralded source |
| Single-Photon Quality ($g^{(2)}(0)$) | 0.0011(2) | N/A | Lower pump power setting (high quality) |
| Heralded Photon Count Rate | 4.5 / 40 | kcps | Lower / Higher pump power settings |
| Radiative Decay Time ($\tau_R$) | 7.68(23) | ns | Higher pump power setting |
| Non-Radiative Decay Time ($\tau_N$) | 107(14) | ps | Higher pump power setting |
| Conversion Efficiency ($\eta_{conv}$) | 1.46(32) $\cdot$ 10-4 | N/A | Higher power setting (sample efficiency) |
| Data Acquisition Time | ~24 | hours | Typical time for reported experiments |
Key Methodologies
Section titled âKey MethodologiesâThe experiment utilized a heralded single-photon source (HSPS) based on Spontaneous Parametric Down Conversion (SPDC) coupled to a custom confocal microscope (CM) setup.
- SPDC Generation: A red laser beam was frequency doubled (BiBO crystal) to produce a blue pump photon, which was then converted via SPDC (PPKTP crystal) into a visible photon (heralded) and an infrared photon (herald).
- Heralding Mechanism: Detection of the infrared photon by a Superconducting Single Photon Detector (SSPD) defined the time reference and heralded the existence of the visible photon.
- Excitation: The heralded visible photon (532 nm) was focused onto the HPHT diamond sample using a Microscope Objective (MO).
- Absorption Mechanism: Absorption occurred via the phonon sideband of the NV centers, enabling nonresonant excitation with the broadband quantum light.
- Fluorescence Collection: The resulting red fluorescence (600-800 nm) was collected by the same MO, filtered (longpass filter > 700 nm), and detected by a Single-Photon Avalanche Diode (SPAD).
- Data Analysis: Time-resolved single-photon detection was used to measure the fluorescence decay statistics, which were fitted to a model accounting for radiative ($\tau_R$) and non-radiative ($\tau_N$) decay paths, and accidental coincidences.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe research highlights the potential of NV diamond for quantum networks but also exposes limitations inherent in using high-density HPHT material, specifically the FRET effect leading to shorter decay times and the inability to address single NV centers. 6CCVDâs MPCVD expertise directly addresses these challenges, enabling researchers to move toward scalable, high-fidelity quantum systems.
Applicable Materials for Replication and Extension
Section titled âApplicable Materials for Replication and ExtensionâThe paper notes that future work requires low NV concentration samples to eliminate FRET and enable single-center addressing. 6CCVD provides the necessary high-purity substrates for controlled NV creation.
| Research Requirement | 6CCVD Material Solution | Technical Advantage |
|---|---|---|
| Low NV Concentration (Required for single-center addressing) | Optical Grade SCD (Single Crystal Diamond) | Extremely low intrinsic nitrogen content (< 1 ppb), allowing for precise, controlled creation of isolated NV centers (e.g., via ion implantation or delta doping). |
| High Density Ensemble (Used in current paper) | High-Purity PCD (Polycrystalline Diamond) | Cost-effective alternative to HPHT for ensemble studies, offering superior thermal management and customizable dimensions up to 125 mm. |
| Advanced Quantum Control (Future applications) | Boron-Doped Diamond (BDD) | Essential for creating conductive diamond electrodes for Stark shift control or integration into microwave circuits. Available in SCD or PCD formats. |
Customization Potential for Quantum Integration
Section titled âCustomization Potential for Quantum IntegrationâThe experimental setup relied on precise optical alignment and filtering. 6CCVD offers critical material customization services that enhance experimental fidelity and integration potential:
- Custom Dimensions and Thickness: 6CCVD provides SCD and PCD plates/wafers in custom dimensions up to 125 mm (PCD) and thicknesses from 0.1 ”m to 500 ”m (SCD/PCD). This is crucial for matching specific confocal microscope geometries or integrating into photonic chips.
- Ultra-Low Roughness Polishing: The experiment requires high-quality focusing via a microscope objective (MO). 6CCVD guarantees Ra < 1 nm for SCD and Ra < 5 nm for inch-size PCD, minimizing scattering losses and ensuring optimal coupling efficiency for both excitation (532 nm) and fluorescence collection (700-800 nm).
- Custom Metalization Services: While the current setup was purely optical, future cryogenic or microwave-based quantum control experiments often require on-chip electrodes. 6CCVD offers in-house deposition of standard quantum-compatible metals, including Ti, Pt, Au, Pd, W, and Cu, tailored to specific device layouts.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in defect engineering and material science for quantum applications. We can assist researchers in selecting the optimal diamond substrate (SCD vs. PCD), purity level, and post-processing steps (e.g., surface termination, annealing protocols) required to achieve the desired NV density and charge state stability for similar heralded single-photon interaction projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
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 â 575 nm, which overlaps well with the absorption spectrum of nitrogen-vacancy centers.