The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Roberto Paiella - One of the best experts on this subject based on the ideXlab platform.
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Monte Carlo Study of gan versus gaas terahertz quantum cascade structures
Applied Physics Letters, 2008Co-Authors: Enrico Bellotti, Kristina Driscoll, Theodore D. Moustakas, Roberto PaiellaAbstract:Due to their large optical phonon energies, nitride semiconductors are promising for the development of terahertz quantum cascade lasers with dramatically improved high-temperature performance relative to existing GaAs devices. Here, we present a rigorous Monte Carlo Study of carrier dynamics in two structures based on the same design scheme for emission at 2THz, consisting of GaN∕AlGaN or GaAs∕AlGaAs quantum wells. The population inversion and hence the gain coefficient of the nitride device are found to exhibit a much weaker (by a factor of over 3) temperature dependence and to remain large enough for laser action even without cryogenic cooling.
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Monte Carlo Study of the temperature dependent performance of GaN versus GaAs terahertz quantum cascade structures
LEOS 2008 - 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2008Co-Authors: Enrico Bellotti, Kristina Driscoll, Theodore D. Moustakas, Roberto PaiellaAbstract:We present a Monte Carlo Study of the carrier dynamics in terahertz quantum cascade lasers to quantify the potential of GaN/AlGaN over GaAs/AlGaAs quantum wells for high temperature operation.
Enrico Bellotti - One of the best experts on this subject based on the ideXlab platform.
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Monte Carlo Study of gan versus gaas terahertz quantum cascade structures
Applied Physics Letters, 2008Co-Authors: Enrico Bellotti, Kristina Driscoll, Theodore D. Moustakas, Roberto PaiellaAbstract:Due to their large optical phonon energies, nitride semiconductors are promising for the development of terahertz quantum cascade lasers with dramatically improved high-temperature performance relative to existing GaAs devices. Here, we present a rigorous Monte Carlo Study of carrier dynamics in two structures based on the same design scheme for emission at 2THz, consisting of GaN∕AlGaN or GaAs∕AlGaAs quantum wells. The population inversion and hence the gain coefficient of the nitride device are found to exhibit a much weaker (by a factor of over 3) temperature dependence and to remain large enough for laser action even without cryogenic cooling.
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Monte Carlo Study of the temperature dependent performance of GaN versus GaAs terahertz quantum cascade structures
LEOS 2008 - 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2008Co-Authors: Enrico Bellotti, Kristina Driscoll, Theodore D. Moustakas, Roberto PaiellaAbstract:We present a Monte Carlo Study of the carrier dynamics in terahertz quantum cascade lasers to quantify the potential of GaN/AlGaN over GaAs/AlGaAs quantum wells for high temperature operation.
Kristina Driscoll - One of the best experts on this subject based on the ideXlab platform.
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Monte Carlo Study of gan versus gaas terahertz quantum cascade structures
Applied Physics Letters, 2008Co-Authors: Enrico Bellotti, Kristina Driscoll, Theodore D. Moustakas, Roberto PaiellaAbstract:Due to their large optical phonon energies, nitride semiconductors are promising for the development of terahertz quantum cascade lasers with dramatically improved high-temperature performance relative to existing GaAs devices. Here, we present a rigorous Monte Carlo Study of carrier dynamics in two structures based on the same design scheme for emission at 2THz, consisting of GaN∕AlGaN or GaAs∕AlGaAs quantum wells. The population inversion and hence the gain coefficient of the nitride device are found to exhibit a much weaker (by a factor of over 3) temperature dependence and to remain large enough for laser action even without cryogenic cooling.
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Monte Carlo Study of the temperature dependent performance of GaN versus GaAs terahertz quantum cascade structures
LEOS 2008 - 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2008Co-Authors: Enrico Bellotti, Kristina Driscoll, Theodore D. Moustakas, Roberto PaiellaAbstract:We present a Monte Carlo Study of the carrier dynamics in terahertz quantum cascade lasers to quantify the potential of GaN/AlGaN over GaAs/AlGaAs quantum wells for high temperature operation.
Theodore D. Moustakas - One of the best experts on this subject based on the ideXlab platform.
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Monte Carlo Study of gan versus gaas terahertz quantum cascade structures
Applied Physics Letters, 2008Co-Authors: Enrico Bellotti, Kristina Driscoll, Theodore D. Moustakas, Roberto PaiellaAbstract:Due to their large optical phonon energies, nitride semiconductors are promising for the development of terahertz quantum cascade lasers with dramatically improved high-temperature performance relative to existing GaAs devices. Here, we present a rigorous Monte Carlo Study of carrier dynamics in two structures based on the same design scheme for emission at 2THz, consisting of GaN∕AlGaN or GaAs∕AlGaAs quantum wells. The population inversion and hence the gain coefficient of the nitride device are found to exhibit a much weaker (by a factor of over 3) temperature dependence and to remain large enough for laser action even without cryogenic cooling.
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Monte Carlo Study of the temperature dependent performance of GaN versus GaAs terahertz quantum cascade structures
LEOS 2008 - 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2008Co-Authors: Enrico Bellotti, Kristina Driscoll, Theodore D. Moustakas, Roberto PaiellaAbstract:We present a Monte Carlo Study of the carrier dynamics in terahertz quantum cascade lasers to quantify the potential of GaN/AlGaN over GaAs/AlGaAs quantum wells for high temperature operation.
Richard J. Needs - One of the best experts on this subject based on the ideXlab platform.
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Research data supporting "Quantum Monte Carlo Study of the energetics of the rutile, anatase, brookite, and columbite TiO2 polymorphs"
2017Co-Authors: Richard J. Needs, Bartomeu Monserrat, Rios P Lopez, J. R. Trail, Ryo MaezonoAbstract:Data for "Quantum Monte Carlo Study of the energetics of the rutile, anatase, brookite, and columbite TiO2 polymorphs"
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quantum Monte Carlo Study of the phase diagram of solid molecular hydrogen at extreme pressures
Nature Communications, 2015Co-Authors: Neil Drummond, Bartomeu Monserrat, Jonathan H Lloydwilliams, Lopez P Rios, Chris J Pickard, Richard J. NeedsAbstract:These data support "Quantum Monte Carlo Study of the phase diagram of solid molecular hydrogen at extreme pressures" published in Nature Communications: http://dx.doi.org/10.1038/ncomms8794
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A Variational Monte Carlo Study of Positronic Compounds Using Inhomogeneous Backflow Transformations
Chemistry Letters, 2010Co-Authors: Yukiumi Kita, Neil Drummond, Masanori Tachikawa, Richard J. NeedsAbstract:A variational Monte Carlo Study using inhomogeneous backflow transformations is reported for the [H−;e+] and [Li−;e+] positronic compounds. The backflow transformations greatly improve the total energies, positron affinities, and two-photon annihilation rates. The Slater–Jastrow-backflow trial wave function is well suited to the theoretical analysis of positronic compounds.
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Quantum Monte Carlo Study of sodium
Physical Review B, 2003Co-Authors: Ryo Maezono, M. D. Towler, Richard J. NeedsAbstract:We report a variational and diffusion quantum Monte Carlo Study of sodium. Pseudopotentials are used to represent the ion cores, and core-valence correlation effects are included by using a core polarization potential. When the core polarization potential is included we obtain an excellent value for the first ionization energy of the atom and a good value for the cohesive energy of the solid. Variational calculations of the occupied bandwidth give larger values than experiment, in agreement with recent sophisticated many-body calculations. Including the core polarization potential narrows the bandwidth slightly.
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Quantum Monte Carlo Study of silicon self-interstitials
7th International Workshop on Computational Electronics. Book of Abstracts. IWCE (Cat. No.00EX427), 2000Co-Authors: Richard J. NeedsAbstract:An accurate treatment of electron correlation in real materials presents a formidable challenge to condensed matter theorists and quantum chemists. We use the fixed-node diffusion quantum Monte Carlo (DMC) method, which is one of the most accurate methods known for calculating the energies of many-electron systems. The computational cost scales as the cube of the system size, which is much more favourable than other correlated wave function methods, and allows applications to large systems. A basic introduction to the DMC technique is given, and work on self-interstitial defects in silicon is described.