Dynamics of quantum correlation between separated nitrogen-vacancy centers embedded in plasmonic waveguide
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2015-10-23 |
| Journal | Scientific Reports |
| Authors | Wanli Yang, JunâHong An, Chengjie Zhang, Changyong Chen, C. H. Oh |
| Institutions | Chinese Academy of Sciences, Lanzhou University |
| Citations | 14 |
| Analysis | Full AI Review Included |
6CCVD Technical Documentation: Stabilizing Quantum Correlation in NVC-Plasmonic Waveguides
Section titled â6CCVD Technical Documentation: Stabilizing Quantum Correlation in NVC-Plasmonic WaveguidesâThis document summarizes the technical findings of the research paper âDynamics of quantum correlation between separated nitrogen-vacancy centers embedded in plasmonic waveguideâ and outlines how 6CCVDâs advanced MPCVD diamond materials and custom engineering services can support the replication and advancement of this critical quantum information processing (QIP) research.
Executive Summary
Section titled âExecutive SummaryâThis research successfully models and proposes an efficient scheme for establishing stable, long-distance quantum correlation between two Nitrogen-Vacancy (NV) centers coupled via a one-dimensional (1D) plasmonic waveguide (PW).
- Core Achievement: Demonstrating that dynamically induced quantum correlation between NVCs can be stabilized into a long-time steady state (EoF(â) and QD(â)).
- Stabilization Mechanism: Continuous, localized external resonant laser driving ($\Omega_{1}, \Omega_{2}$) applied individually to each NVC.
- Mediating Environment: A 1D plasmonic waveguide facilitates both coherent (dipole-dipole, $g_{12}$) and incoherent (correlated spontaneous emission, $\Gamma_{12}$) coupling, which can be modulated by NVC separation distance ($d$).
- Long-Distance Capability: Stable quantum correlation is achieved even when the NVC separation distance ($d$) is much larger than the operating plasmonic wavelength ($\lambda_{pl}$).
- System Requirements: The system requires ultra-high purity, low-strain single crystal diamond (SCD) as the host material for the NVCs, integrated with precisely fabricated plasmonic nanostructures.
- Application Focus: This scheme provides a prerequisite for devising active, decoherence-immune solid-state optical devices and scalable, long-distance NVC-based quantum networks.
Technical Specifications
Section titled âTechnical SpecificationsâThe following key physical and experimental parameters were utilized or calculated in the NVC-PW system model:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Emitter Material | Nitrogen-Vacancy (NV) Centers | N/A | Embedded in diamond nanocrystals (spin triplet ground state). |
| Transition Wavelength ($\lambda_{pl}$) | 637 | nm | Corresponding to the operating wavelength of the plasmon mode. |
| Plasmon Propagation Length (L) | 2 | ”m | Effective length used in simulations. |
| NVC-PW Vertical Separation (h) | 180 | nm | Distance optimized for efficient coupling. |
| Interqubit Distance (d) | $\lambda_{pl}/4$ up to $3\lambda_{pl}$ | N/A | Demonstrates stability over distances much greater than the wavelength. |
| Coupling Factor ($\beta$) | 0.94 or 0.99 | N/A | Measures the fraction of NVC emission captured by the propagating plasmon mode. |
| Spontaneous Emission Rate | $\Gamma$ | N/A | Used as the normalization unit for driving frequencies ($\Omega$). |
| Rabi Frequencies ($\Omega$) | 0.1$\Gamma$ to 0.3$\Gamma$ | N/A | Magnitudes of continuous external laser driving fields for stabilization. |
| Coupling Regimes | Coherent ($g_{12}$) and Incoherent ($\Gamma_{12}$) | N/A | Modulated by distance $d$ via sine and cosine dependence on $k_{pl}d$. |
| Temperature Environment | $\sim 4$ | K | Required for accessing the strong NVC-PW coupling regime, though room temperature optimization is sought. |
Key Methodologies
Section titled âKey MethodologiesâThe research relies on advanced quantum electrodynamics (QED) modeling to analyze the dynamics of the coupled NVC-PW system.
- System Definition: The model established a hybrid solid-state system consisting of two identical NVCs coupled to a 1D plasmonic waveguide, acting as a common radiation field medium.
- Quantum Master Equation: The time evolution of the systemâs quantum correlation ($\rho(t)$) was determined by employing the Born-Markovian approximation, tracing out the degrees of freedom of the plasmonic waveguide (PW).
- Plasmon-Mediated Coupling: Interactions between the NVCs were quantified through the plasmon contribution of Greenâs function ($G_{pl}$):
- Coherent Dipole-Dipole Rate ($g_{12}$): Proportional to the Real part of $G_{pl}$.
- Incoherent Emission Rate ($\Gamma_{12}$): Proportional to the Imaginary part of $G_{pl}$.
- Distance-Based Modulation: The $\pi/2$ phase difference between $g_{12}$ (sine-dependent) and $\Gamma_{12}$ (cosine-dependent) allowed for the effective switching on/off of the coherent or incoherent contributions solely by tailoring the interqubit distance ($d$).
- Correlation Metrics: Quantum correlation was quantified and compared using two established non-classicality metrics: Quantum Discord (QD) and Entanglement of Formation (EoF).
- Steady-State Stabilization: Continuous, localized external resonant laser fields, characterized by Rabi frequencies ($\Omega_{1}, \Omega_{2}$), were applied to the NVCs to counteract environmental decoherence and stabilize the quantum correlation in the long-time limit.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD provides the specialized MPCVD diamond materials and engineering precision necessary to replicate and advance this critical work in plasmonic quantum networks.
| Research Requirement/Challenge | 6CCVD Solution & Capability | Sales Advantage |
|---|---|---|
| High-Purity Quantum Host Material | Optical Grade Single Crystal Diamond (SCD): Ultra-low native nitrogen concentration (high purity) for controlled NV center creation via ion implantation or targeted growth. | Guarantees minimum intrinsic noise and maximum NVC coherence time (essential for operating QIP devices, especially at room temperature). |
| Precise Geometric Coupling | Custom Dimensions & Thickness Control: SCD layers available from 0.1 ”m up to 500 ”m, allowing precise integration onto specialized substrates, controlling the crucial NVC-PW vertical separation ($h=180$ nm). | We deliver wafers up to 125 mm (PCD) with required thicknesses and custom laser cutting services for specific nanophotonic integration geometries. |
| Plasmonic Waveguide Fabrication | Internal Metalization Services: Capabilities for high-fidelity deposition and patterning of common plasmonic materials: Au, Pt, Pd, Ti, W, and Cu. | Provides turnkey integration of the plasmonic nanostructure (e.g., V-groove waveguide or nanowire) directly onto the high-purity diamond substrate, minimizing fabrication complexity for researchers. |
| Interfacial Quality & Low Loss | Ultra-Smooth Polishing: SCD polishing capability achieving surface roughness Ra < 1 nm. | Critical for maximizing the NVC-PW coupling factor ($\beta$) and propagation length (L=2 ”m), reducing scattering losses, and enhancing Purcell factors required for strong coupling. |
| Long-Distance Network Scalability | Advanced PCD/SCD Substrates: Availability of large-area PCD and SCD substrates suitable for scaling complex, distributed quantum architectures. | Supports the transition from proof-of-concept experiments to large-scale NVC-based quantum networks that leverage the long-distance correlation demonstrated in this study. |
Engineering Support
Section titled âEngineering SupportâThis research directly addresses challenges in realizing scalable, solid-state quantum networks that rely on robust NV center coherence. 6CCVDâs in-house PhD engineering team specializes in assisting customers with material selection, optimizing diamond growth parameters for controlled NV density, and designing material geometries (thickness and metalization) necessary to achieve strong coupling regimes in Plasmonic Quantum Electrodynamics (QED) projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract We investigate the dynamics of quantum correlation between two separated nitrogen vacancy centers (NVCs) placed near a one-dimensional plasmonic waveguide. As a common medium of the radiation field of NVCs propagating, the plasmonic waveguide can dynamically induce quantum correlation between the two NVCs. It is interesting to find that such dynamically induced quantum correlation can be preserved in the long-time steady state by locally applying individual driving on the two NVCs. In particular, we also show that a large degree of quantum correlation can be established by this scheme even when the distance between the NVCs is much larger than their operating wavelength. This feature may open new perspectives for devising active decoherence-immune solid-state optical devices and long-distance NVC-based quantum networks in the context of plasmonic quantum electrodynamics.