Single phonon source based on a giant polariton nonlinear effect
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2018-02-27 |
| Journal | Optics Letters |
| Authors | Kang Cai, Zi-Wen Pan, Rui Xia Wang, Dong Ruan, Zhang-Qi Yin |
| Citations | 18 |
| Analysis | Full AI Review Included |
Technical Analysis & Documentation: Single Phonon Source in Diamond NV Centers
Section titled âTechnical Analysis & Documentation: Single Phonon Source in Diamond NV CentersâThis documentation analyzes the research paper âSingle phonon source based on a giant acoustic nonlinear effectâ and maps its material requirements directly to the capabilities of 6CCVDâs proprietary MPCVD diamond products.
Executive Summary
Section titled âExecutive SummaryâThis paper proposes a high-performance, measurement-free source for generating single phonons, a key component for advancing quantum information processing and optomechanics. The realization relies critically on the unique properties of diamond hosting Nitrogen-Vacancy (NV) centers within a precisely engineered phononic crystal resonator.
- Core Achievement: Numerical demonstration of a robust single phonon source based on a giant acoustic nonlinearity realized in a diamond NV-center ensemble.
- Methodology: Utilizes a four-level NV system driven by optical and microwave fields to exhibit Coherent Population Trapping (CPT), yielding zero linear susceptibility and giant nonlinear enhancement.
- Key Quantum Metric: Confirmed successful preparation of a single quantum field by achieving a second-order correlation function $g^{(2)}(0) < 1$ (sub-Poissonian antibunching).
- Material Necessity: Requires ultra-high purity Single Crystal Diamond (SCD) to minimize thermal noise and achieve the required high quality factor ($Q = 10^{6}$) for the phononic crystal resonator.
- System Parameters: The scheme is shown to be effective at cryogenic temperatures (0.5 K) and requires balancing large optical detuning ($\delta = 40 \text{ MHz}$) against the effective coupling strength ($g/2\pi = 25 \text{ kHz}$) to suppress unwanted decay channels.
- 6CCVD Value: 6CCVD is positioned as the ideal supplier of Optical Grade SCD wafers required for the growth of high-Q diamond phononic crystals and long-coherence NV center operation.
Technical Specifications
Section titled âTechnical SpecificationsâThe following table extracts the critical hard data points and simulation parameters used in the numerical analysis of the single phonon source proposal.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Target Quantum Metric | $g^{(2)}(0) < 1$ | N/A | Sub-Poissonian distribution (single phonon state) |
| Operating Temperature | 0.5 | K | Required to maintain low mean thermal polariton number (0.1) |
| NV Center Ensemble Count ($N$) | 40000 | N/A | Number of NV centers in the ensemble |
| Effective Nonlinear Coupling ($g / 2\pi$) | 25 | kHz | Strength of effective giant nonlinear interaction |
| Phonon Mode Frequency ($\omega_m / 2\pi$) | 800 | MHz | Surface acoustic mode frequency |
| Optical Field Detuning ($\delta / 2\pi$) | 40 | MHz | Large detuning required to suppress spontaneous decay |
| Electron-Phonon Coupling Rate ($g_{13} / 2\pi$) | 1 | kHz | Baseline coupling rate |
| Optical Driving Frequency ($\Omega_d / 2\pi$) | 20 | kHz | Rabi frequency of the optical laser driving |
| System Dissipation ($\gamma$) | $g/8$ | N/A | Approximated dissipation rate for polariton P$_{0}$ |
| Phononic Crystal Quality Factor ($Q$) | $10^{6}$ | N/A | High-Q factor used to calculate phonon dissipation ($\gamma_p$) |
Key Methodologies
Section titled âKey MethodologiesâThe experiment relies on a precise sequence of material structuring, field driving, and adiabatic control to isolate and transform the dark polariton state into a single phonon.
- Material Setup: An ensemble of NV centers is located near the surface of a diamond phononic crystal resonator. The diamond provides the necessary crystal structure and strain coupling mechanism.
- Four-Level System Construction: The NV center is modeled as a four-level system (three ground spin states $|-1\rangle, |0\rangle, |+1\rangle$ and one excited state $|E_y\rangle$).
- External Driving: The system is simultaneously driven by:
- An Optical Laser Field ($\Omega_c$) to couple the excited state and the $|0\rangle$ spin state.
- A Microwave Field ($\Omega_d$) to drive the transition between ground spin states $|0\rangle$ and $|+1\rangle$.
- Effective Hamiltonian Generation: The high-frequency optical field is eliminated using the Schrieffer-Wolff transformation, leading to an effective Hamiltonian ($\text{H}{\alpha}$) where the coupling strength is renormalized ($g{24} = g_{24}\Omega_c/\omega_m$).
- Polariton Transformation: The Hamiltonian is redefined in terms of polariton operators ($\text{P}0, \text{P}{\pm}$). The dark state polariton $\text{P}_0$ is utilized as it exhibits giant nonlinearity and zero linear susceptibility, enabling quantum preparation.
- Single Polariton Preparation: The dark state polariton $\text{P}_0$ is prepared using a tailored microwave driving strength $\Omega$, optimized to minimize $g^{(2)}(0)$ and reach the minimal thermal polariton number at 0.5 K.
- Adiabatic Transformation to Phonon: Once the dark polariton is prepared, the microwave driving strength $\Omega_d(t)$ is adiabatically adjusted ($v \ll \mu_{\pm}$) until the dark state polariton evolves entirely into the desired single phonon state, realizing the source.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâReplicating and extending this state-of-the-art research requires diamond materials with exceptional purity and dimensional control, precisely matching 6CCVDâs core competencies.
Applicable Materials
Section titled âApplicable MaterialsâTo achieve the required coherence times and high resonator quality factors ($Q = 10^{6}$), researchers must utilize Optical Grade Single Crystal Diamond (SCD) grown via Microwave Plasma Chemical Vapor Deposition (MPCVD).
| 6CCVD Material | Specific Application Match | Key Benefit |
|---|---|---|
| Optical Grade SCD (Low N content) | Substrate for NV center ensemble hosting (low intrinsic noise) | Achieves maximum coherence time ($T_2$) for NV qubits, critical for quantum applications. |
| Thin SCD Wafers (0.1”m - 500”m) | Construction of the high-Q diamond phononic crystal resonator | Provides the structural integrity and precise thickness control required for acoustic mode engineering (800 MHz resonance). |
| Heavy Boron-Doped Diamond (BDD) | (Potential Extension) Creating integrated electrodes or contacts for enhanced electro-acoustic modulation in similar optomechanical systems. | Allows integration of active electronic components directly into the diamond matrix. |
Customization Potential
Section titled âCustomization PotentialâThe construction of diamond phononic crystal resonators demands exacting geometric precision and potential integration with control circuitry. 6CCVD is uniquely equipped to meet these needs:
- Custom Dimensions: We offer SCD and PCD plates/wafers up to 125mm, allowing for large-scale fabrication of integrated quantum chips or larger experimental stages.
- Precision Thinning and Etching: 6CCVD provides custom diamond thickness control (SCD 0.1”m to 500”m) essential for defining specific acoustic mode frequencies ($\omega_m$).
- Advanced Polishing: We guarantee ultra-smooth surfaces critical for lithographic patterning of the phononic crystal (Ra < 1nm for SCD).
- Integrated Metalization: If the experimental setup requires integrated metallic contact pads or waveguides for microwave/optical driving fields (e.g., Ti/Pt/Au for ohmic contacts), 6CCVD offers internal, custom metalization capabilities (Au, Pt, Pd, Ti, W, Cu).
Engineering Support
Section titled âEngineering SupportâDeveloping quantum devices based on NV centers and phononics requires deep expertise across material science and quantum mechanics.
- 6CCVDâs in-house PhD team can assist with material selection for similar NV-Phononic Quantum Information Processing projects, ensuring the substrate purity, orientation, and thickness are optimized for implantation success and acoustic coupling rates.
- We offer consultation on selecting the optimal diamond material for both high-Q mechanical elements and long-coherence spin platforms.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
We propose a single phonon source based on nitrogen-vacancy (NV) centers, which are located in a diamond phononic crystal resonator. The strain in the lattice would induce the coupling between the NV centers and the phonon mode. The strong coupling between the excited state of the NV centers and the phonon is realized by adding an optical laser driving. This four-level NV center system exhibits coherent population trapping and yields giant resonantly enhanced acoustic nonlinearities, with zero linear susceptibility. Based on this nonlinearity, the single phonon source can be realized. We numerically calculate g<sup>(2)</sup>(0) of the single phonon source. We discuss the effects of the thermal noise and the external driving strength.