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
Adam Filipkowski, Mariusz Mrozek, Grzegorz Stepniewski, Jakub Kierdaszuk, Aneta Drabinska, Tanvi Karpate, Maciej Glowacki, Mateusz Ficek, Wojciech Gawlik, Ryszard Buczynki, Adam Wojciechowski, Robert Bogdanowicz, Mariusz Klimczak
Summary: This research proposes a novel method for integrating diamond particles containing nitrogen-vacancy centers directly into the fiber core, and verifies its magnetic sensing performance. By manually controlling the distribution of diamond particles in the fiber core, precise control over nanoscale features is achieved. The experimental results show that this integration method can achieve uniform distribution of diamond particles in the fiber without significant agglomeration. Furthermore, the fiber demonstrates good magnetic sensing capabilities in the presence of a magnetic field, with a large dynamic range.
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
Nanoscience & Nanotechnology
Emilio Corte, Greta Andrini, Elena Nieto Hernandez, Vanna Pugliese, Angelo Costa, Goele Magchiels, Janni Moens, Shandirai Malven Tunhuma, Renan Villarreal, Lino M. C. Pereira, Andre Vantomme, Joao Guilherme Correia, Ettore Bernardi, Paolo Traina, Ivo Pietro Degiovanni, Ekaterina Moreva, Marco Genovese, Sviatoslav Ditalia Tchernij, Paolo Olivero, Ulrich Wahl, Jacopo Forneris
Summary: We conducted the first comprehensive characterization of the structural and photoluminescence properties of optically active centers formed through implantation of Mg+ ions in synthetic diamond. Using electron emission channeling technique, we analyzed the structural configurations of Mg-related defects and observed a major fraction of Mg atoms (around 30% to 42%) in sites consistent with the split-vacancy structure of the MgV complex. Photoluminescence emission studies revealed new spectral features and provided insights into the optimal conditions for stable and intense emission. Our findings have significant implications for quantum information processing applications utilizing the tunable properties of the MgV center.
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
Materials Science, Multidisciplinary
Qing Ai, Peng-Bo Li, Wei Qin, Jie-Xing Zhao, C. P. Sun, Franco Nori
Summary: This study demonstrates that nitrogen-vacancy (NV) centers in diamond can produce a unique quantum hyperbolic metamaterial, with a hyperbolic dispersion relation that can be engineered and dynamically tuned by applying a magnetic field. This quantum hyperbolic metamaterial allows for negative refraction and can be used for subwavelength imaging, spontaneous emission enhancement, and other applications in various fields.
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
Optics
A. K. Dmitriev, A. K. Vershovskii
Summary: This study investigates the response of the level anticrossing signal to a quasiresonant radio-frequency field in zero magnetic field at nitrogen-vacancy (NV) color centers in diamond. It is demonstrated that the complex structure of this response can be explained by the Autler-Townes splitting. The possibility of controlling the parameters of the level anticrossing signal is considered, and it is shown that the slope of the central resonance recorded in this structure can be 2.3 times higher than the slope of the resonance recorded in the absence of a radio-frequency field. Conclusions are drawn about the nature of the level anticrossing effect in NV color centers in diamond under zero magnetic field.
Article
Materials Science, Multidisciplinary
Tongtong Zhang, Madhav Gupta, Jixiang Jing, Zhongqiang Wang, Xuyun Guo, Ye Zhu, Yau Chuen Yiu, Tony K. C. Hui, Qi Wang, Kwai Hei Li, Zhiqin Chu
Summary: The superior properties of diamond make it a versatile platform for various applications. By using salt-assisted air-oxidized nanodiamonds as chemical vapor deposition (CVD) seeds, high-quality diamond microparticles with superior optical properties can be grown.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Optics
Zong-Da Zhang, Si-Yu Yin, Li-Cheng Wang, Ying-De Wang, Yun-Fei Li, Zhen-Nan Tian, Qi-Dai Chen
Summary: An array of single NV centers was prepared using the femtosecond laser direct writing method to address the accuracy and consistency issues in static magnetic field detection. The prepared NV centers have fewer defects and good stress uniformity, with an average spatial positioning error of only 0.2 μm. This array enables high accuracy measurement of magnetic field vector and gradient.
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
Quantum Science & Technology
Takeyuki Tsuji, Takeharu Sekiguchi, Takayuki Iwasaki, Mutsuko Hatano
Summary: Extending the spin-dephasing time of NV centers in CVD diamonds can enhance the magnetic sensitivity. The study shows that adjusting the misorientation angle can mitigate stress distribution and increase the spin-dephasing time of NV centers.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Physics, Multidisciplinary
Yong Li, Xiaozhou Chen, Maowu Ran, Yanchao She, Zhengguo Xiao, Meihua Hu, Ying Wang, Jun An
Summary: The synthesis of diamond with varying nitrogen concentrations changes the color of the crystals and allows for control of different nitrogen impurity concentrations. The presence of specific optical color centers can be observed in diamond crystals at specific nitrogen concentrations, an important finding.
Article
Chemistry, Physical
Mariusz Mrozek, Mateusz Schabikowski, Marzena Mitura-Nowak, Janusz Lekki, Marta Marszalek, Adam M. Wojciechowski, Wojciech Gawlik
Summary: The experimental study focused on the longitudinal and transverse relaxation of negatively charged nitrogen-vacancy centers in diamond monocrystals prepared by 1.8 MeV proton implantation. Results showed that proton implantation technique can be versatile in controlling the production of nitrogen-vacancy color centers in thin films.
Article
Chemistry, Physical
Gergely Barcza, Anton Pershin, Adam Gali, Oers Legeza
Summary: This paper investigates the convergence properties of density matrix renormalisation group (DMRG) calculations for vertical electronic excitations on three bimolecular complexes, comparing the results with high-level coupled-cluster reference spectrum and other theoretical solutions. It demonstrates that extrapolated solutions based on low bond-dimensional DMRG data can provide quantitative predictions even for large active spaces by taking advantage of error cancellation effects, and that orbital optimisation can further improve the accuracy of the DMRG results, approaching the excitation energies of coupled cluster single-double-triple at similar computational costs.
Article
Multidisciplinary Sciences
Peter Deak, Peter Udvarhelyi, Gergo Thiering, Adam Gali
Summary: Thermal equilibrium is the state where a system reaches its lowest energy level, but it is not always guaranteed that the ground state can be eventually reached. In the case of carbon pairs in silicon, multiple configurations exist and the most thermodynamically stable configuration may not be realized due to the formation kinetics. This study shows that a complex defect in silicon has a bistable nature, and the formation of less stable configurations is favored over the most stable configuration, potentially overlooking key candidates for quantum technology applications.
NATURE COMMUNICATIONS
(2023)
Review
Nanoscience & Nanotechnology
Adam Gali
Summary: Solid-state defects as single photon sources and quantum bits play important roles in quantum technologies. However, not all properties and behaviors of known solid-state defect quantum bits are fully understood, and new solutions are needed for various quantum technologies. In this review, we discuss recent developments in the field, including methods for calculating excited states, treatment of spatially extended wavefunctions, temperature-dependent fluorescence spectrum and photo-ionization thresholds, calculation of magneto-optical parameters, spin-phonon interaction, spin dephasing, and spin-echo times. Breakthroughs in describing excited states of deep defects and understanding the leading microscopic effect in spin relaxation are highlighted.
Article
Chemistry, Multidisciplinary
Fabian A. Freire-Moschovitis, Roberto Rizzato, Anton Pershin, Moritz R. Schepp, Robin D. Allert, Lina M. Todenhagen, Martin S. Brandt, Adam Gali, Dominik B. Bucher
Summary: Quantum sensing with spin defects in diamond, such as the nitrogen vacancy (NV) center, allows for the detection of chemical species on the nanoscale. A surprising effect is observed where diamagnetic electrolyte solutions increase the relaxation time of NV centers near the surface. This effect is attributed to a change in interfacial band bending due to the formation of an electric double layer.
Article
Chemistry, Physical
David Hall, Juan Carlos Sancho-Garcia, Anton Pershin, David Beljonne, Eli Zysman-Colman, Yoann Olivier
Summary: The importance of intermediate triplet states and the nature of excited states in the TADF mechanism has garnered increasing interest. Current understanding suggests that a more complex route involving higher-lying locally excited triplet excited states is necessary to accurately describe the rate of reverse intersystem crossing (RISC), rather than simple conversion between charge transfer (CT) triplet and singlet excited states. In this study, computational methods were compared to predict the relative energy and nature of excited states in TADF emitters, and it was found that the TDA-DFT method with specific functionals demonstrated the best agreement with the reference method SCS-CC2.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Jeffrey Neethi Neethirajan, Toni Hache, Domenico Paone, Dinesh Pinto, Andrej Denisenko, Rainer Stoehr, Peter Udvarhelyi, Anton Pershin, Adam Gali, Joerg Wrachtrup, Klaus Kern, Aparajita Singha
Summary: Near-surface negatively charged nitrogen vacancy (NV) centers show promise for magnetic imaging and quantum sensing, but their charge-state instabilities decrease fluorescence and NV coherence time, negatively affecting imaging sensitivity. In this study, we demonstrate that in situ adsorption of H2O on the diamond surface can partially recover the performance of shallow NV sensors. Controlled surface treatments are essential for implementing NV-based quantum sensing protocols under cryogenic ultrahigh vacuum conditions, as supported by band-bending calculations.
Article
Engineering, Electrical & Electronic
Amine Slassi, Adam Gali, Jerome Cornil, Anton Pershin
Summary: We systematically investigate the chemical doping of WSe2 monolayer by non-covalently attaching electron donor and acceptor molecules. Our results show that the physisorbed molecules stack on WSe2 via weak van der Waals interactions and do not significantly damage the monolayer structure. The carrier density and work function of the monolayer are modified by the organic dopants, with a maximum change of 0.41 eV. The adsorbed molecules can also modulate the spatial localization of vacancy trap states and stabilize charged defect states associated with vacancies.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Physical
Abdelhadi El Jaouhari, Amine Slassi, Xihuan Zhang, Anton Pershin, Hassan Ait Ahsaine, Chunyue Li, Yuanhua Lin
Summary: In this study, ultra-small cobalt oxide nanoparticles are anchored on the surface of nitrogen-doped porous 3D graphitic carbon nano-spheres to increase the amount of exposed active sites and avoid self-agglomeration. The obtained electrocatalyst exhibits superior OER activity and exceptional stability in alkaline electrolyte. DFT calculations demonstrate that the strong adsorption of Co3O4 on N-doped graphene improves the stability of Co3O4 nanoparticles during OER process.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Multidisciplinary
Szabolcs Czene, Nikoletta Jegenyes, Olga Krafcsik, Sandor Lenk, Zsolt Czigany, Gabor Bortel, Katalin Kamaras, Janos Rohonczy, David Beke, Adam Gali
Summary: Silicon carbide nanoparticles (SiC NPs) are potential inorganic molecular-sized fluorescent biomarkers, and researchers have developed a method to directly introduce amino groups into aqueous SiC NPs. The applicability of amino-terminated SiC NPs is demonstrated by attaching bovine serum albumin, and it is found that the fluorescence intensity is highly sensitive to surface termination, which may have implications for nanometer-sized SiC NPs with optically read electron spins.
Article
Physics, Applied
Jyh-Pin Chou, Peter Udvarhelyi, Nathalie P. de Leon, Adam Gali
Summary: We propose a simple model to explain the existence and chemical stability of surface spins associated with the sp3 dangling bond on the (100) diamond surface using density-functional theory. Our study reveals a mechanism for annihilation of these surface spins upon annealing, consistent with recent experimental results. We also demonstrate that the Fermi-contact term in the hyperfine coupling is not negligible between the surface spins and the surrounding nuclear spins, and thus ab initio simulation can be used to devise a sensing protocol where the surface spins act as reporter spins to sense nuclear spins on the surface.
PHYSICAL REVIEW APPLIED
(2023)
Article
Chemistry, Physical
Peter Udvarhelyi, Tristan Clua-Provost, Alrik Durand, Jiahan Li, James H. H. Edgar, Bernard Gil, Guillaume Cassabois, Vincent Jacques, Adam Gali
Summary: Researchers determine the coupling of boron-vacancy spin defect (V-B(-)) in hexagonal boron nitride (hBN) to strain and electric fields using first-principles calculations. Their work reveals the interplay between local piezoelectric and elastic effects in the response to electric fields. Theoretical predictions are used to analyze optically detected magnetic resonance (ODMR) spectra on hBN crystals with varying densities of V-B(-) centers, confirming that the orthorhombic zero-field splitting parameter is a result of local electric fields from surrounding charge defects. This study paves the way for applications of V-B(-) centers in quantitative electric field imaging and quantum sensing under pressure.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Physics, Multidisciplinary
D. Wirtitsch, G. Wachter, S. Reisenbauer, M. Gulka, V. Ivady, F. Jelezko, A. Gali, M. Nesladek, M. Trupke
Summary: We propose and experimentally demonstrate a method to increase the sensitivity of spin measurements on nitrogen vacancy (NV) centers in diamond by utilizing the charge state transitions of the defect. The method involves a two-step procedure of purifying the charge state and obtaining high spin polarization. The results show significant improvement in spin contrast and reduction in initialization error.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
N. Dontschuk, L. V. H. Rodgers, J. P. Chou, D. A. Evans, K. M. O'Donnell, H. J. Johnson, A. Tadich, A. K. Schenk, A. Gali, N. P. de Leon, A. Stacey
Summary: Identifying the surface chemistry of diamond materials is crucial for device applications, especially in quantum sensors. Oxygen-related termination species are commonly used due to their abundance, stability, and compatibility with nitrogen vacancy centres. However, it is challenging to accurately identify and quantify the different groups on diamond surfaces. This study combines x-ray absorption and photoelectron spectroscopies to quantitatively identify the coverage of carbonyl functional groups on the {100} diamond surface, revealing unexpected complexities in the spectroscopy of oxygen terminated diamond surfaces.
MATERIALS FOR QUANTUM TECHNOLOGY
(2023)
