Article
Chemistry, Multidisciplinary
Alexander Wood, Artur Lozovoi, Zi-Huai Zhang, Sachin Sharma, Gabriel I. Lopez-Morales, Harishankar Jayakumar, Nathalie P. de Leon, Carlos A. Meriles
Summary: Using confocal fluorescence microscopy, we observe the charge interconversion process between all three charge states of the silicon vacancy (SiV) center in diamond at room temperature. We uncover the two-step capture process of diffusing, photogenerated holes that leads to the formation of SiV0, and demonstrate the reverse process induced by continuous red illumination. These findings provide insight into the charge dynamics of SiV and hold promise for nanoscale sensing and quantum information processing.
Article
Chemistry, Physical
Chengyuan Yang, Zhaohong Mi, Huining Jin, Thirumalai Venkatesan, Ratnakar Vispute, Andrew A. Bettiol
Summary: We report a method for large-scale fabrication of negatively charged Silicon-vacancy (SiV-) centers in diamond membranes using MeV Helium ion implantation. Despite the polycrystalline structure of the diamond membranes, the SiV- centers exhibit a fluorescence lifetime comparable to those fabricated in single crystal diamonds. Patterning of SiV- centers with varying densities is demonstrated using a focused ion beam.
Article
Chemistry, Multidisciplinary
Frantisek Trojanek, Karol Hamracek, Martin Hanak, Marian Varga, Alexander Kromka, Oleg Babcenko, Lukas Ondic, Petr Maly
Summary: Diamond thin films with a high-density of light-emitting negatively charged silicon vacancy (SiV) centers can be prepared at a relatively low cost, which has potential applications in photonics or sensing. The composition of the films, which consist of diamond grains with SiV centers and sp(2)-carbon phase, can be adjusted by changing the preparation conditions. Surface defects and the sp(2)-related defects in the grains can trap the carriers excited within the SiV centers, leading to a decrease in their internal photoluminescence (PL) quantum efficiency.
Article
Physics, Applied
Kelsey M. Bates, Matthew W. Day, Christopher L. Smallwood, Rachel C. Owen, Tim Schroder, Edward Bielejec, Ronald Ulbricht, Steven T. Cundiff
Summary: An ensemble of silicon vacancy (SiV-) centers in diamond was probed using two-pulse correlation spectroscopy and multidimensional coherent spectroscopy. Two main distinct families of SiV- centers were identified, and local strain tensor was calculated based on measured spectra. Variations in strain tensor were observed at multiple points on the sample surface.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
Shahriar Aghaeimeibodi, Daniel Riedel, Alison E. Rugar, Constantin Dory, Jelena Vuckovic
Summary: The study investigates the electrical tuning of Sn-V- centers in diamond through the direct-current Stark effect, demonstrating a tuning range beyond 1.7 GHz with both quadratic and linear dependence on the applied electric field. The researchers confirm that the observed tuning effect is a result of the applied electric field, distinct from thermal tuning due to Joule heating, suggesting Stark tuning as a promising avenue to overcome detunings between emitters and enabling the realization of multiple identical quantum nodes.
PHYSICAL REVIEW APPLIED
(2021)
Article
Materials Science, Multidisciplinary
Jiaqi Lu, Bing Yang, Biao Yu, Haining Li, Nan Huang, Lusheng Liu, Xin Jiang
Summary: This study introduces a simple two-step method to enhance the photoluminescence efficiency of optically active silicon-vacancy (SiV) centers using silicon-doped diamond nanoneedles. By selectively etching nanocrystalline diamond and sp(2) carbon, the photoluminescence emission of SiV centers in diamond nanoneedles is increased by up to 12.1 times, revealing the significant impact of sp(2) carbon on the optical collection of color centers at the sidewall.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Vadim Sedov, Artem Martyanov, Ivan Tiazhelov, Alexey Romshin, Dmitrii Pasternak, Kirill Boldyrev, Vladimir Krivobok, Sergey Savin, Pavel Pivovarov, Milos Nesladek, Victor Ralchenko
Summary: In this study, Ge-doped polycrystalline diamond (PCD) and single-crystal diamond (SCD) materials were synthesized using microwave plasma chemical vapor deposition (MPCVD). The structure and luminescence characteristics of these materials were analyzed. The absorption of Ge-V centers in both PCD and SCD materials at low temperatures was demonstrated for the first time. The narrowing of the Ge-V photoluminescence line for the SCD sample compared to the PCD sample was observed, while the intensity of the Ge-V signal was higher in the PCD sample. Single Ge-V centers formed during chemical vapor deposition (CVD) were also demonstrated. These results provide a foundation for the manufacture and design of various photonic devices based on Ge-V color centers.
DIAMOND AND RELATED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Aedan Gardill, Ishita Kemeny, Matthew C. Cambria, Yanfei Li, Hossein T. Dinani, Ariel Norambuena, Jeronimo R. Maze, Vincenzo Lordi, Shimon Kolkowitz
Summary: The control over charge states of color centers in solids is crucial for quantum technologies, but the microscopic charge dynamics of deep defects remain complex and unknown. By utilizing single-shot charge-state readout of an individual nitrogen-vacancy (NV) center, researchers were able to probe the charge dynamics of surrounding defects in diamond and demonstrate the charge conversion ability of optical illumination in capturing holes. This study sheds light on the importance of charge carrier generation, transport, and capture in quantum device design with color centers, offering a novel approach to probe and control charge dynamics in diamond.
Article
Multidisciplinary Sciences
Alexander Savvin, Alexander Dormidonov, Evgeniya Smetanina, Vladimir Mitrokhin, Evgeniy Lipatov, Dmitriy Genin, Sergey Potanin, Alexander Yelisseyev, Viktor Vins
Summary: The authors successfully demonstrated lasing in (NV-) centers in diamond, achieving improved laser efficiency by fine-tuning the pump conditions to reduce photoionization. Investigation into lasing conditions and gain saturation was conducted under high-power laser pulse pumping of diamond crystal.
NATURE COMMUNICATIONS
(2021)
Article
Optics
Bo Du, Xiang-Dong Chen, Ze-Hao Wang, Shao-Chun Zhang, En-Hui Wang, Guang-Can Guo, Fang-Wen Sun
Summary: The study found that nitrogen vacancy defects in diamond exhibit fluorescence anomalous saturating effect under high power laser excitation, increasing the nonlinearity of fluorescence emission and altering the spatial frequency distribution of the fluorescence image. High spatial frequency information can be extracted using a differential excitation protocol, and by modulating the excitation laser's power, the spatial resolution of imaging is improved approximately 1.6 times compared to confocal microscopy. This method, due to its simplicity in experimental setup and data processing, has potential for enhancing spatial resolution in sensing and biological labeling with defects in solids.
PHOTONICS RESEARCH
(2021)
Article
Chemistry, Multidisciplinary
Disheng Chen, Johannes E. Froch, Shihao Ru, Hongbing Cai, Naizhou Wang, Giorgio Adamo, John Scott, Fuli Li, Nikolay Zheludev, Igor Aharonovich, Weibo Gao
Summary: This study successfully observed resonance fluorescence from GeV color centers in diamond by using cross-polarization to suppress laser scattering and achieved two-photon interference based on single GeV color center. The single-shot readout of spin states was also demonstrated, laying the foundation for building a quantum network with GeV color centers in diamond.
Article
Physics, Applied
A. F. M. Almutairi, J. G. Partridge, Chenglong Xu, I. S. Cole, A. S. Holland
Summary: In this study, arrays of divacancy centers were created in 4H-SiC using femtosecond laser irradiation and subsequent thermal annealing. The divacancy centers were characterized by photoluminescence and Raman spectroscopy, and it was found that the maximum divacancy center emission was achieved at 800°C.
APPLIED PHYSICS LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Jan Fait, Marian Varga, Karel Hruska, Alexander Kromka, Bohuslav Rezek, Lukas Ondic
Summary: Researchers have demonstrated a new and simple two-step method for fabricating diamond PhC slabs with leaky modes overlapping the emission line of the silicon vacancy (SiV) centers. By first fabricating a PhC structure with leaky modes blue shifted from the SiV emission line in nanocrystalline diamond without SiV centers, and then depositing a thin layer of SiV-rich diamond over the PhC slab to adjust the spectral position of the PhC leaky modes to the emission line of the SiV centers, an intensity enhancement of the zero-phonon line of the SiV centers by a factor of nine is achieved. This PhC tuning method has potential applications for other optical centers and photonic structures in various materials.
Article
Chemistry, Physical
Bing Yang, Haining Li, Biao Yu, Jiaqi Lu, Nan Huang, Lusheng Liu, Xin Jiang
Summary: The addition of TMS gas during the CVD process can improve the photoluminescence efficiency of SiV centers and form diamond/SiC composite films with high-brightness SiV centers. However, excessive TMS gas flow leads to an increase in SiC concentration and deterioration of photoluminescence of SiV centers.
Article
Nanoscience & Nanotechnology
Lukas Ondic, Frantisek Trojanek, Marian Varga, Jan Fait
Summary: Femtosecond laser irradiation can reduce the background photoluminescence intensity and enhance the emission peak intensity of SiV centers in nanocrystalline diamond thin films. This process also leads to the release of strain, improving the optical quality and enabling potential applications in photonic nanostructures.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Qinghai Tan, Jia-Min Lai, Xue-Lu Liu, Dan Guo, Yongzhou Xue, Xiuming Dou, Bao-Quan Sun, Hui-Xiong Deng, Ping-Heng Tan, Igor Aharonovich, Weibo Gao, Jun Zhang
Summary: This study reports dense single-photon emitters (SPEs) in hexagonal boron nitride (hBN) and provides evidence that most of these SPEs can be well explained by donor-acceptor pairs (DAPs). The findings contribute to the understanding of SPEs in hBN and their applications in quantum technologies.
Article
Chemistry, Multidisciplinary
Yongliang Chen, Chi Li, Tieshan Yang, Evgeny A. Ekimov, Carlo Bradac, Son Tung Ha, Milos Toth, Igor Aharonovich, Toan Trong Tran
Summary: All-optical nanothermometry is a powerful tool for measuring nanoscale temperatures in various applications. This study presents a real-time nanothermometry technique using codoped nanodiamonds with high sensitivity and resolution. The technique utilizes temperature sensors that emit spectrally separated fluorescence signals and a parallel detection scheme for fast readout. The method is demonstrated by monitoring temperature changes in microcircuits and MoTe2 field-effect transistors.
Article
Optics
Milad Nonahal, Chi Li, Haoran Ren, Lesley Spencer, Mehran Kianinia, Milos Toth, Igor Aharonovich
Summary: Integrated quantum photonics (IQP) offers a practical and scalable approach to quantum computation, communications, and information processing. However, the limited range of materials for monolithic platforms has been a challenge. This study demonstrates the fabrication of IQP components from hexagonal boron nitride (hBN), including waveguides, microdisks, and photonic crystal cavities. The engineered circuitry using single-crystal hBN shows the potential of hBN for scalable integrated quantum technologies.
LASER & PHOTONICS REVIEWS
(2023)
Review
Nanoscience & Nanotechnology
Alejandro R. -P. Montblanch, Matteo Barbone, Igor Aharonovich, Mete Atature, Andrea C. Ferrari
Summary: This review highlights the role of transition metal dichalcogenides, hexagonal boron nitride, and stacked heterostructures in various quantum technology applications. Layered materials have attractive properties for quantum technologies and have already shown potential in scalable components such as light sources, photon detectors, and nanoscale sensors. The review discusses the opportunities and challenges faced by these materials in the field of quantum technologies, particularly in applications relying on light-matter interfaces.
NATURE NANOTECHNOLOGY
(2023)
Editorial Material
Physics, Condensed Matter
Igor Aharonovich
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Yongliang Chen, Simon White, Evgeny A. Ekimov, Carlo Bradac, Milos Toth, Igor Aharonovich, Toan Trong Tran
Summary: We present an ultralow-power, optical thermometry technique for cryogenic temperatures using a two-level system in nanodiamonds. This technique achieves a relative sensitivity of about 20% K-1 at 5 K, higher than other optical nanothermometry methods, while employing excitation powers of just a few tens of nanowatts. We demonstrate its ability to accurately measure temperature differences at various locations on a custom-made microcircuit. This study is significant for the advancement of nanoscale optical thermometry at cryogenic temperatures.
Article
Quantum Science & Technology
Ali Al-Juboori, Helen Zhi Jie Zeng, Minh Anh Phan Nguyen, Xiaoyu Ai, Arne Laucht, Alexander Solntsev, Milos Toth, Robert Malaney, Igor Aharonovich
Summary: This study demonstrates a discrete-variable quantum key distribution system using a bright single photon source in hexagonal-boron nitride, operating at room temperature. With an easily interchangeable photon source system, keys with a length of one million bits, and a secret key of approximately 70000 bits, at a quantum bit error rate of 6%, with ε-security of 10(-10) are generated. This is the first proof of concept finite-key BB84 QKD system realized with hBN defects.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Chemistry, Multidisciplinary
Islay O. O. Robertson, Sam C. C. Scholten, Priya Singh, Alexander J. J. Healey, Fernando Meneses, Philipp Reineck, Hiroshi Abe, Takeshi Ohshima, Mehran Kianinia, Igor Aharonovich, Jean-Philippe Tetienne
Summary: Detecting magnetic noise from small quantities of paramagnetic spins is achieved using spin defects in hexagonal boron nitride (hBN). Negatively charged boron vacancy defects are created in ultra-thin hBN nanoflakes, and the longitudinal spin relaxation time (T1) is measured. By decorating the dry hBN nanopowder with paramagnetic Gd3+ ions, a clear T1 quenching under ambient conditions is observed, indicating the presence of added magnetic noise. Spin measurements, including T1 relaxometry, can also be performed using solution-suspended hBN nanopowder. These findings demonstrate the potential and versatility of hBN quantum sensors for various sensing applications and pave the way towards a truly 2D, ultrasensitive quantum sensor.
Article
Chemistry, Multidisciplinary
Wei Wen Wong, Naiyin Wang, Bryan D. D. Esser, Stephen A. A. Church, Li Li, Mark Lockrey, Igor Aharonovich, Patrick Parkinson, Joanne Etheridge, Chennupati Jagadish, Hark Hoe Tan
Summary: In this study, we utilize the selective area epitaxy method to deterministically engineer thousands of microring lasers on a single chip. By elucidating a detailed growth mechanism and controlling the adatom diffusion lengths, we achieve ultrasmooth cavity sidewalls. These engineered devices exhibit a tunable emission wavelength in the telecommunication O-band and show low-threshold lasing with high device efficacy across the chip. This work marks a significant milestone toward the implementation of a fully integrated III-V materials platform for next-generation high-density integrated photonic and optoelectronic circuits.
Article
Physics, Applied
Thinh N. Tran, Angus Gale, Benjamin Whitefield, Vladimir Dyakonov, Milos Toth, Igor Aharonovich, Mehran Kianinia
Summary: By designing and fabricating a microwave double arc resonator, efficient transferring of the microwave field was achieved for optically addressable spin defects in hexagonal boron nitride (hBN), resulting in enhanced optically detected magnetic resonance (ODMR) contrast and low magnetic field sensitivity. This robust and scalable device engineering holds promise for future applications of spin defects in hBN for quantum sensing.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Yongliang Chen, Angus Gale, Karin Yamamura, Jake Horder, Alexander Condos, Kenji Watanabe, Takashi Taniguchi, Milos Toth, Igor Aharonovich
Summary: Reliable methods for creating quantum emitters in hBN are in high demand for scalable applications in quantum photonic devices. This study focuses on defects in hBN with a zero phonon line at 2.8 eV (436 nm) and utilizes carbon-doped hBN crystals irradiated by an electron beam to generate these emitters. The stability of the emitters is investigated through annealing treatments, revealing that the blue emitters are stable up to approximately 800 degrees C. However, annealing at 1000 degrees C results in the disappearance of the emitters and the appearance of a family of other emitters in the irradiated region of hBN. These findings contribute to our understanding of emitter species and formation in hBN.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Milad Nonahal, Jake Horder, Angus Gale, Lu Ding, Chi Li, Madeline Hennessey, Son Tung Ha, Milos Toth, Igor Aharonovich
Summary: Light-matter interactions in optical cavities are crucial for integrated quantum photonics applications. Hexagonal boron nitride (hBN) has emerged as a promising van der Waals platform for quantum emitters, but progress has been hindered by the inability to simultaneously engineer an hBN emitter and a narrow-band photonic resonator. In this study, we overcome this challenge by demonstrating deterministic fabrication of hBN nanobeam photonic crystal cavities with high quality factors across a broad spectral range. We also create a monolithic cavity-emitter system tailored for a blue quantum emitter, induced deterministically through electron beam irradiation. This work presents a promising approach for scalable on-chip quantum photonics and opens up possibilities for quantum networks based on van der Waals materials.
Article
Chemistry, Multidisciplinary
Angus Gale, Dominic Scognamiglio, Ivan Zhigulin, Benjamin Whitefield, Mehran Kianinia, Igor Aharonovich, Milos Toth
Summary: Negatively charged boron vacancies (VB-) in hexagonal boron nitride (hBN) have become of interest as spin defects for quantum information processing and quantum sensing. This study investigates the switching of charge states of VB defects in hBN under laser and electron beam excitation, demonstrating deterministic and reversible switching between the -1 and 0 states controlled by excess electrons or holes injected into hBN by a layered heterostructure device. This work provides a means to monitor and manipulate the charge state of VB defects, enabling the stabilization of the -1 state necessary for spin manipulation and optical readout.
Article
Engineering, Electrical & Electronic
Kee Suk Hong, Hee-Jin Lim, Dong Hoon Lee, In-Ho Bae, Kwang-Yong Jeong, Christoph Becher, Sejeong Kim, Igor Aharonovich
Summary: Single-photon sources based on single emitters are highly interesting for various applications and have been realized using different materials. Common factors related to relaxation times of internal states indirectly affect the photon number stability. GaN emitters demonstrate higher stability due to faster relaxation times compared to hBN emitters, but hBN emitters have higher photon generation rates. Repeatable radiant flux measurements of a bright hBN single-photon emitter for a wide range of fluxes have been demonstrated.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Materials Science, Multidisciplinary
Ivan Zhigulin, Karin Yamamura, Viktor Ivady, Angus Gale, Jake Horder, Charlene J. Lobo, Mehran Kianinia, Milos Toth, Igor Aharonovich
Summary: This study presents a detailed photophysical analysis of blue-emitting hexagonal boron nitride single emitters and reveals their potential level structure. The results are important for understanding blue quantum emitters in hBN as potential sources for scalable quantum photonic applications.
MATERIALS FOR QUANTUM TECHNOLOGY
(2023)
