Storage and retrieval of solitons in electromagnetically induced transparent system of V-type three-level diamond nitrogen-vacancy color centers

At a Glance

Metadata	Details
Publication Date	2024-01-01
Journal	Acta Physica Sinica
Authors	Cong Tan, Wang Deng-Long, Yaoyong Dong, Jianwen Ding
Citations	1
Analysis	Full AI Review Included

Technical Documentation & Analysis: V-Type Three-Level NV Center Soliton Storage

Research Paper Analyzed: Storage and retrieval of solitons in electromagnetically induced transparent system of V-type three-level diamond nitrogen-vacancy color centers (Acta Phys. Sin. Vol. 73, No. 10 (2024) 107601)

Executive Summary

This research validates the use of diamond Nitrogen-Vacancy (NV) color centers in a V-type three-level Electromagnetically Induced Transparency (EIT) configuration for stable quantum information storage.

Core Achievement: Successful theoretical demonstration of stable soliton storage and retrieval in a V-type NV center EIT system, overcoming stability limitations found in cold atomic and quantum dot media.
Mechanism: Soliton storage and retrieval are achieved by dynamically switching the magnetic induction ($B_c$) of the strong control field on and off.
High Fidelity: Solitons, formed by the balance of dispersion and nonlinearity, maintain high fidelity (stable amplitude and waveform) during storage and retrieval, unlike weak or strong pulses.
Tunability: The width of the EIT transparency window and the amplitude of the stored soliton can be precisely modulated by adjusting the control magnetic induction ($B_c$).
Material Advantage: NV centers in diamond offer the critical advantages of room-temperature operation, long electron spin coherence times, and high stability, making them superior solid-state platforms for quantum memory.
6CCVD Relevance: This work confirms the critical need for high-purity, low-strain Single Crystal Diamond (SCD) substrates, a core offering of 6CCVD, for advancing solid-state quantum computing and quantum memory applications.

Technical Specifications

The following hard data points were extracted from the simulation parameters used to model the V-type NV center EIT system:

Parameter	Value	Unit	Context
NV Center Ground State Splitting ($D_{gs}$)	2.87	GHz	Energy difference between $
Control Field Magnetic Induction ($B_c$)	25, 50, 280 (max tested)	mT	Used to open/widen the EIT window and modulate soliton amplitude
Probe Field Detuning ($\Delta$_p) Range	$\pm 8 \times 10^{8}$	Hz	Range tested for linear absorption characteristics
Spontaneous Decay Rate ($\Gamma$₃₁)	0.35	MHz	Level $
Spontaneous Decay Rate ($\Gamma$₂₁)	0.11	MHz	Level $
Dephasing/Decoherence Rates ($\gamma$₂₁, $\gamma$₃₁)	44	MHz	Coherence decay rates
Dephasing/Decoherence Rate ($\gamma$₃₂)	0.5	MHz	Coherence decay rate
Characteristic Time ($\tau$₀)	$7 \times 10^{-8}$	s	Characteristic time length of the probe field
Propagation Coefficient ($k$₁₃)	$2.3 \times 10^{10}$	cm $\cdot$ s^-1	Probe field propagation constant
Soliton Propagation Distance (Max Simulated)	17.5	cm	Demonstrated stable propagation for strong pulses ($x/2L$_D = 6)

Key Methodologies

The experiment relies on a semi-classical theoretical framework combining quantum mechanics (Bloch equations) and classical electrodynamics (Maxwell equations) to model the NV center interaction with the electromagnetic fields.

System Construction: A V-type three-level NV center EIT model is constructed. The weak probe field ($\omega$_p) couples the $|1\rangle \leftrightarrow |3\rangle$ transition, and the strong control field ($\omega$_c) couples the $|1\rangle \leftrightarrow |2\rangle$ transition.
Hamiltonian Formulation: The system Hamiltonian is derived in the Schrödinger picture, including the Zeeman effect induced by the static magnetic field ($B_0$) and the time-varying probe/control fields ($B_{p(c)}(t)$).
Maxwell-Bloch (M-B) Equations: The dynamics are governed by the coupled M-B equations, describing the evolution of the density matrix elements ($\rho_{ij}$) and the propagation of the probe field ($\Omega_p$).
Multi-Scale Perturbation Method: Due to the complexity of the M-B equations, the multi-scale method is employed to derive approximate solutions, leading to the nonlinear Schrödinger equation (NLSE) for the probe field envelope ($U$).
Soliton Control Simulation: Soliton storage and retrieval are simulated numerically using the Runge-Kutta method, employing a hyperbolic tangent function to model the switching (on/off) of the control field magnetic induction ($B_c$).

6CCVD Solutions & Capabilities

This research highlights the critical role of high-quality diamond substrates for realizing stable, room-temperature quantum memory devices based on NV centers. 6CCVD is uniquely positioned to supply the necessary materials and customization services required to replicate and scale this research.

Applicable Materials

To achieve the high fidelity and long coherence times necessary for stable soliton storage, the material must be of the highest quality.

6CCVD Material	Specification	Relevance to Soliton Storage
Single Crystal Diamond (SCD)	Optical Grade, Low Strain, High Purity (Type IIa)	Essential for long spin coherence times ($T_2$) and minimal spectral diffusion, crucial for NV center stability.
Custom N-Doped SCD	Controlled Nitrogen concentration (PPM or PPB level)	Precise control over the density of NV precursors (substitutional Nitrogen) is required for optimal EIT density ($N_a$).
Polished SCD Wafers	Surface Roughness (Ra < 1 nm)	Minimizes optical scattering losses for the probe and control fields, ensuring efficient EIT and soliton propagation.

Customization Potential

The simulation demonstrates stable soliton propagation over distances up to 17.5 cm, suggesting a need for large-area, high-uniformity diamond material for practical device integration.

Large-Area Substrates: 6CCVD offers Polycrystalline Diamond (PCD) wafers up to 125 mm in diameter and SCD substrates up to 10 mm thick, enabling the fabrication of long-path waveguides or large-scale quantum chips necessary for long-distance quantum information transmission.
Precision Thickness Control: We provide SCD and PCD plates with thicknesses ranging from 0.1 µm to 500 µm, allowing researchers to optimize the interaction length and waveguide geometry for EIT experiments.
Integrated Metalization Services: While the paper focuses on magnetic control, practical NV center devices often require integrated microwave control lines. 6CCVD provides in-house custom metalization (including Ti/Pt/Au, Pd, W, Cu) for fabricating on-chip microwave antennas or electrodes directly onto the diamond surface.
Advanced Polishing: We guarantee ultra-smooth surfaces, with Ra < 1 nm for SCD and Ra < 5 nm for inch-size PCD, critical for minimizing optical losses in integrated photonic structures.

Engineering Support

6CCVD’s in-house team of PhD material scientists specializes in the growth and characterization of diamond for quantum applications. We offer consultation services to assist researchers in material selection for similar NV Center Quantum Memory and EIT projects. Our expertise ensures that the diamond substrate meets the stringent requirements for high-fidelity quantum control, including precise doping and defect engineering.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

<sec>Compared with light, the solitons, which are from the balance between dispersion and nonlinearity of the system, possess high stability and fidelity as the information carries in quantum information processing and transmission, and have gained considerable attention in ultra-cold atomic electromagnetically induced transparent (EIT) media. To date, the EIT models on the three-level ultra-cold atoms realized experimentally, are ladder-, <inline-formula><tex-math id=“M1”>\begin{document}$\Lambda $\end{document}</tex-math><alternatives><graphic specific-use=“online” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“10-20232006_M1.jpg”/><graphic specific-use=“print” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“10-20232006_M1.png”/></alternatives></inline-formula>-, and V-type mode. Current studies show that the solitons cannot be stored in V-type three-level ultra-cold atomic EIT media but they can be stored in ladder- and<inline-formula><tex-math id=“M2”>\begin{document}$\Lambda $\end{document}</tex-math><alternatives><graphic specific-use=“online” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“10-20232006_M2.jpg”/><graphic specific-use=“print” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“10-20232006_M2.png”/></alternatives></inline-formula>-type three-level ultra-cold atomic EIT media. It is mainly because the atoms of the V-type system initially are in a excited state, while the atoms of the ladder- and <inline-formula><tex-math id=“M3”>\begin{document}$\Lambda $\end{document}</tex-math><alternatives><graphic specific-use=“online” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“10-20232006_M3.jpg”/><graphic specific-use=“print” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“10-20232006_M3.png”/></alternatives></inline-formula>-type systems initially are in the ground state. For the practical applications, it is a large challenge to control accurately the solitons stored in the ultra-cold atomic EIT media due to their ultralow temperature and rarefaction. Fortunately, with the maturity of semiconductor quantum technology, quantum dots have extensively application prospect in quantum information processing and transmission. However, the solitons cannot be stored in V-type three level InAs/GaAs quantum dot EIT media either, while it can be stored in ladder-type system and <inline-formula><tex-math id=“M4”>\begin{document}$\Lambda $\end{document}</tex-math><alternatives><graphic specific-use=“online” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“10-20232006_M4.jpg”/><graphic specific-use=“print” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“10-20232006_M4.png”/></alternatives></inline-formula>-type system.</sec><sec>Therefore, herein we propose a V-type three-level nitrogen-vacancy (NV) center EIT model in which a weakprobe field and a strong control field are coupled to different energy levels of NV center in diamond. Subsequently, the linear and nonlinear properties of system are studied by using semiclassical theory combined with multi-scale method. It is shown that when control field is turned on, the linear absorption curve of the system presents an EIT window. And the width of the EIT window increases with the strength of magnetic induction of the control field increasing. In the nonlinear case, the solitons formed can stably propagate over a long distance. Interestingly, the solitons can be stored and retrieved by switching off and on the magnetic field of control field. Moreover, the amplitude of the stored solitons can be modulated by the magnetic induction strength of control field. This result indicates that solitons as information carriers in quantum information processing and transmission of NV center can greatly improve the fidelity of information processing.</sec>

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Original Source

DOI: https://doi.org/10.7498/aps.73.20232006