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Study of narrowband single photon emitters in polycrystalline diamond films  [PDF]
Russell G. Sandstrom,Olga Shimoni,Aiden A. Martin,Igor Aharonovich
Physics , 2014, DOI: 10.1063/1.4901083
Abstract: Quantum information processing and integrated nanophotonics require robust generation of single photon emitters on demand. In this work we demonstrate that diamond films grown by microwave plasma chemical vapour deposition on a silicon substrate host bright, narrowband single photon emitters in the visible to near infrared spectral range. The emitters possess fast lifetime, absolute photostability, and exhibit full polarization at excitation and emission. Pulsed and continuous laser excitations confirm their quantum behaviour at room temperature, while low temperature spectroscopy is done to investigate their inhomogeneous broadening. Our results advance the knowledge of solid state single photon sources and open pathways for their practical implementation in quantum communication and quantum information processing.
Photophysics of single silicon vacancy centers in diamond: implications for single photon emission  [PDF]
Elke Neu,Mario Agio,Christoph Becher
Physics , 2012, DOI: 10.1364/OE.20.019956
Abstract: Single silicon vacancy (SiV) color centers in diamond have recently shown the ability for high brightness, narrow bandwidth, room temperature single photon emission. This work develops a model describing the three level population dynamics of single SiV centers in diamond nanocrystals on iridium surfaces including an intensity dependent de-shelving process. Furthermore, we investigate the brightness and photostability of single centers and find maximum single photon rates of 6.2 Mcps under continuous excitation. We investigate the collection efficiency of the fluorescence and estimate quantum efficiencies of the SiV centers.
Engineering chromium related single photon emitters in single crystal diamond  [PDF]
I Aharonovich,S Castelletto,B C Johnson,J C McCallum,S Prawer
Physics , 2010, DOI: 10.1088/1367-2630/13/4/045015
Abstract: Color centers in diamond as single photon emitters, are leading candidates for future quantum devices due to their room temperature operation and photostability. The recently discovered chromium related centers are particularly attractive since they possess narrow bandwidth emission and a very short lifetime. In this paper we investigate the fabrication methodologies to engineer these centers in monolithic diamond. We show that the emitters can be successfully fabricated by ion implantation of chromium in conjunction with oxygen or sulfur. Furthermore, our results indicate that the background nitrogen concentration is an important parameter, which governs the probability of success to generate these centers.
Chromium single photon emitters in diamond fabricated by ion implantation  [PDF]
Igor Aharonovich,Stefania Castelletto,Brett C. Johnson,Jeffrey C. McCallum,David A. Simpson,Andrew D. Greentree,Steven Prawer
Physics , 2010, DOI: 10.1103/PhysRevB.81.121201
Abstract: Controlled fabrication and identification of bright single photon emitters is at the heart of quantum optics and materials science. Here we demonstrate a controlled engineering of a chromium bright single photon source in bulk diamond by ion implantation. The Cr center has fully polarized emission with a ZPL centered at 749 nm, FWHM of 4 nm, an extremely short lifetime of ~1 ns, and a count rate of 500 kcounts/s. By combining the polarization measurements and the vibronic spectra, a model of the center has been proposed consisting of one interstitial chromium atom with a transition dipole along one of the <100> directions.
Imaging and quantum efficiency measurement of chromium emitters in diamond  [PDF]
I. Aharonovich,S. Castelletto,B. C. Gibson,B. C. Johnson,S. Prawer
Physics , 2010,
Abstract: We present direct imaging of the emission pattern of individual chromium-based single photon emitters in diamond and measure their quantum efficiency. By imaging the excited state transition dipole intensity distribution in the back focal plane of high numerical aperture objective, we determined that the emission dipole is oriented nearly orthogonal to the diamond-air interface. Employing ion implantation techniques, the emitters were engineered with various proximities from the diamond-air interface. By comparing the decay rates from the single chromium emitters at different depths in the diamond crystal, an average quantum efficiency of 28% was measured.
Single photon emitters based on Ni/Si related defects in single crystalline diamond  [PDF]
David Steinmetz,Elke Neu,Jan Meijer,Wolfgang Bolse,Christoph Becher
Physics , 2010, DOI: 10.1007/s00340-011-4402-x
Abstract: We present investigations on single Ni/Si related color centers produced via ion implantation into single crystalline type IIa CVD diamond. Testing different ion dose combinations we show that there is an upper limit for both the Ni and the Si dose 10^12/cm^2 and 10^10/cm^2 resp.) due to creation of excess fluorescent background. We demonstrate creation of Ni/Si related centers showing emission in the spectral range between 767nm and 775nm and narrow line-widths of 2nm FWHM at room temperature. Measurements of the intensity auto-correlation functions prove single-photon emission. The investigated color centers can be coarsely divided into two groups: Drawing from photon statistics and the degree of polarization in excitation and emission we find that some color centers behave as two-level, single-dipole systems whereas other centers exhibit three levels and contributions from two orthogonal dipoles. In addition, some color centers feature stable and bright emission with saturation count rates up to 78kcounts/s whereas others show fluctuating count rates and three-level blinking.
Photophysics of single nitrogen-vacancy centers in diamond nanocrystals  [PDF]
M. Berthel,O. Mollet,G. Dantelle,T. Gacoin,S. Huant,A. Drezet
Physics , 2015, DOI: 10.1103/PhysRevB.91.035308
Abstract: A study of the photophysical properties of nitrogen-vacancy (NV) color centers in diamond nanocrystals of size of 50~nm or below is carried out by means of second-order time-intensity photon correlation and cross-correlation measurements as a function of the excitation power for both pure charge states, neutral and negatively charged, as well as for the photochromic state, where the center switches between both states at any power. A dedicated three-level model implying a shelving level is developed to extract the relevant photophysical parameters coupling all three levels. Our analysis confirms the very existence of the shelving level for the neutral NV center. It is found that it plays a negligible role on the photophysics of this center, whereas it is responsible for an increasing photon bunching behavior of the negative NV center with increasing power. From the photophysical parameters, we infer a quantum efficiency for both centers, showing that it remains close to unity for the neutral center over the entire power range, whereas it drops with increasing power from near unity to approximately 0.5 for the negative center. The photophysics of the photochromic center reveals a rich phenomenology that is to a large extent dominated by that of the negative state, in agreement with the excess charge release of the negative center being much slower than the photon emission process.
Integrated Diamond Optics for Single Photon Detection  [PDF]
P. Siyushev,F. Kaiser,V. Jacques,I. Gerhardt,S. Bischof,H. Fedder,J. Dodson,M. Markham,D. Twitchen,F. Jelezko,J. Wrachtrup
Physics , 2010, DOI: 10.1063/1.3519849
Abstract: Optical detection of single defect centers in the solid state is a key element of novel quantum technologies. This includes the generation of single photons and quantum information processing. Unfortunately the brightness of such atomic emitters is limited. Therefore we experimentally demonstrate a novel and simple approach that uses off-the-shelf optical elements. The key component is a solid immersion lens made of diamond, the host material for single color centers. We improve the excitation and detection of single emitters by one order of magnitude, as predicted by theory.
Multiple intrinsically identical single photon emitters in the solid-state  [PDF]
Lachlan J. Rogers,Kay D. Jahnke,T. Teraji,Luca Marseglia,Christoph. Müller,Boris Naydenov,Hardy Schauffert,C. Kranz,Junichi Isoya,Liam P. McGuinness,Fedor Jelezko
Physics , 2013, DOI: 10.1038/ncomms5739
Abstract: Emitters of indistinguishable single photons are crucial for the growing field of quantum technologies. To realize scalability and increase the complexity of quantum optics technologies, multiple independent yet identical single photon emitters are also required. However typical solid-state single photon sources are inherently dissimilar, necessitating the use of electrical feedback or optical cavities to improve spectral overlap between distinct emitters. Here, we demonstrate bright silicon-vacancy (SiV-) centres in low-strain bulk diamond which intrinsically show spectral overlap of up to 91% and near transform-limited excitation linewidths. Our results have impact upon the application of single photon sources for quantum optics and cryptography, and the production of next generation fluorophores for bio-imaging.
Broad-band spectral control of single photon sources using a nonlinear photonic crystal cavity  [PDF]
Murray W. McCutcheon,Darrick E. Chang,Yinan Zhang,Mikhail D. Lukin,Marko Loncar
Physics , 2009,
Abstract: Motivated by developments in quantum information science, much recent effort has been directed toward coupling individual quantum emitters to optical microcavities. Such systems can be used to produce single photons on demand, enable nonlinear optical switching at a single photon level, and implement functional nodes of a quantum network, where the emitters serve as processing nodes and photons are used for long-distance quantum communication. For many of these practical applications, it is important to develop techniques that allow one to generate outgoing single photons of desired frequency and bandwidth, enabling hybrid networks connecting different types of emitters and long-distance transmission over telecommunications wavelengths. Here, we propose a novel approach that makes use of a nonlinear optical resonator, in which the single photon originating from the atom-like emitter is directly converted into a photon with desired frequency and bandwidth using the intracavity nonlinearity. As specific examples, we discuss a high-finesse, TE-TM double-mode photonic crystal cavity design that allows for direct generation of single photons at telecom wavelengths starting from an InAs/GaAs quantum dot with a 950 nm transition wavelength, and a scheme for direct optical coupling of such a quantum dot with a diamond nitrogen-vacancy center at 637 nm.
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