Quantum emission from hexagonal boron nitride
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2019-12-01 |
| Journal | Journal and proceedings of the Royal Society of New South Wales |
| Authors | Toan Trong Tran |
| Institutions | University of Technology Sydney |
| Analysis | Full AI Review Included |
Technical Documentation and Analysis: Quantum Emitters in Wide Bandgap Materials
Section titled âTechnical Documentation and Analysis: Quantum Emitters in Wide Bandgap Materialsâ6CCVD Ref: QA-HBN-001 | Source: Trong Toan Tran, Thesis Abstract, 2019
Executive Summary
Section titled âExecutive SummaryâThe reported research investigates novel quantum light sources using defect centers in hexagonal boron nitride (hBN), positioning this new material alongside established wide-bandgap platforms like diamond and silicon carbide. This work highlights the continuous demand for ultra-high-purity substrates suitable for advanced quantum integration.
- Core Achievement: Demonstrated high-brightness quantum emission from defect centers in two-dimensional hBN.
- Performance Metrics: Achieved a record single photon count rate exceeding 4 megahertz (MHz) at room temperature.
- Stability: Emitters demonstrated extremely high operational stability under high excitation power at ambient conditions.
- Defect Identification: Spin-resolved Density Functional Theory (DFT) calculations suggest the active defect is an antisite nitrogen vacancy (NBVN).
- Scalability & Engineering: Successful implementation of nanofabrication techniques enabled emitter engineering and resonant excitation.
- Integration Potential: Significant enhancement (Purcell factor of several times) was demonstrated by coupling hBN emitters to plasmonic particle arrays.
- 6CCVD Value: As the premier supplier of MPCVD Single Crystal Diamond (SCD), 6CCVD provides the necessary benchmark materials and ultra-smooth, high-purity substrates required for comparative studies and hybrid quantum integration architectures.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Single Photon Count Rate (Maximum) | > 4 | MHz | Achieved at Room Temperature |
| Operational Temperature | Room | °C | Ambient Conditions |
| Emitter Stability | Extremely High | N/A | Observed under high excitation |
| Emission Polarization | Fully Linear | N/A | Intrinsic property of the hBN emitters |
| Host Material Dimensionality | Two-Dimensional | N/A | Hexagonal Boron Nitride (hBN) |
| Enhancement Mechanism | Purcell Factor | Several Times | Coupling to plasmonic particle arrays |
| Identified Defect Center (DFT) | Antisite Nitrogen Vacancy | N/A | NBVN structure suggested |
Key Methodologies
Section titled âKey MethodologiesâThe experimental strategy focused on material introduction, characterization, defect identification, and interface engineering required for scalable quantum light sources.
- Material Introduction: Introduction of novel quantum systems hosted in hexagonal boron nitride (hBN), a wide bandgap 2D semiconductor.
- Performance Measurement: Measurement and confirmation of high single photon count rates (up to 4+ MHz) and stability under high excitation at room temperature.
- Theoretical Modeling: Use of spin-resolved Density Functional Theory (DFT) calculation to model and suggest the defect center structure (antisite nitrogen vacancy).
- Emitters Engineering: Application of various nanofabrication techniques to precisely engineer and tailor the quantum emitters in hBN.
- Excitation Demonstration: Successful demonstration of resonant excitation capability for the engineered quantum emitters.
- Purcell Enhancement: Integration and coupling of hBN emitters to plasmonic particle arrays, resulting in significant radiative decay rate enhancement.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research validates the critical role of highly stable, wide bandgap materials (like diamond) in developing next-generation quantum technologies. 6CCVD specializes in providing the MPCVD diamond substrates necessary to benchmark, integrate, and scale these systems.
| Research Requirement | 6CCVD Material & Service Recommendation | Technical Capability Match |
|---|---|---|
| Benchmark Material | Optical Grade Single Crystal Diamond (SCD): Required for direct comparison against well-established emitters (e.g., NV centers). Our SCD offers high purity and ultra-low strain necessary for high-coherence experiments. | SCD thickness: 0.1”m - 500”m. Ra < 1nm polished surfaces. |
| Hybrid Integration | Custom Thin-Film SCD/PCD: To integrate 2D materials (like hBN) onto high-thermal conductivity platforms, thin diamond films are optimal. | Plates up to 125mm. Substrates up to 10mm thickness available. |
| Plasmonic Coupling | Metalization Services (Ti/Pt/Au): The use of plasmonic arrays requires precise metal deposition and patterning. 6CCVD provides internal metalization capabilities for Au, Pt, Pd, Ti, W, and Cu layers. | Custom metal stack development and deposition capability. |
| Nanofabrication Readiness | Ultra-Smooth Polishing: Successful nanofabrication relies on flawless substrate surfaces. Our advanced polishing achieves Ra < 1nm for SCD, crucial for lithography and atomic layer deposition. | Polishing quality meets requirements for deep sub-micron patterning. |
| High Excitation Support | Diamond Substrate Thermal Management: For experiments involving high excitation power, diamondâs superior thermal conductivity prevents thermal quenching and preserves emitter stability. | SCD provides over 2000 W/mK thermal conductivity. |
| Expert Consultation | In-House Engineering Team: The complexity of quantum defect engineering necessitates expert consultation on material purity, boron doping (BDD), and crystallographic orientation. | PhD-level material scientists available for project support. |
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Realization of quantum technologies demands successful assembly of crucial building blocks. Quantum light sources, lying at the heart of this architecture, have attracted a great deal of research focus during the last several decades. Optically active defect-based centers in wide bandgap materials such as diamond and silicon carbide have been proven to be excellent candidates due to their high brightness and photostability. Integration of quantum emitters on an on-chip integrated circuit, however, favors low dimensionality of the host materials. Single photon sources embedded in two-dimensional lattices are, therefore, highly desired. In this thesis, we introduce a class of novel quantum systems hosted in hexagonal boron nitride (hBN) - a wide bandgap semiconductor in the two-dimensional (2D) limit. First, we demonstrate experimentally that the quantum systems possess a record high single photon count rate, exceeding 4 MHz at room temperature. Polarization and time-resolved spectroscopy reveal their full emission polarization and short excited state lifetime (~3 ns). Besides, the emitters from this class of quantum system also show extremely high stability under high excitation at ambient conditions. By employing spin-resolved density functional theory (DFT) calculation, we suggest that the defect center is an antisite nitrogen vacancy (NÊVÉŽ). A multicolor phenomenon where there is a wide distribution of zero-phonon lines (ZPL) from different emitters is also observed and can be attributed to strain field in the hBN lattice thanks to DFT calculation. Additionally, we demonstrate the ability to create the emitters by means of thermal treatment or electron beam induced etching. Under harsh environments, strikingly, most of the emitters survive and preserve their quantum properties. Resonant excitation spectroscopy reveals a linewidth of ~6 GHz, and a high single photon purity confirmed from an emitter by on-resonance antibunching measurements. Studies on bulk hBN crystals reveal that the emitters tend to locate at dislocations or stacking faults in the crystals. We also demonstrate ion implantation and laser ablation as means of increasing formation yield of the emitters in mechanically exfoliated hBN flakes. Next, the coupling of quantum emitters in hBN to plasmonic particles arrays is demonstrated, showing several times Purcell enhancement factor. Lastly, we show that another 2D material - tungsten disulfide (WSâ) - when being oxidized also hosts quantum emitters at room temperature. This observation, therefore, opens a new avenue for studying quantum emitters embedded in other 2D materials.