The Experts below are selected from a list of 23943 Experts worldwide ranked by ideXlab platform
J.m. Gerard - One of the best experts on this subject based on the ideXlab platform.
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Acoustic Phonon sidebands in the emission line of single InAs/GaAs quantum dots
Physical Review B, 2003Co-Authors: Ivan Favero, Guillaume Cassabois, Robson Ferreira, David Darson, Christophe Voisin, Jérôme Tignon, Claude Delalande, G. Bastard, Ph. Roussignol, J.m. GerardAbstract:We present an experimental and theoretical study of the existence of Acoustic Phonon sidebands in the emission line of single self-assembled InAs/GaAs quantum dots. Temperature-dependent photoluminescence measurements reveal a deviation from a Lorentzian profile with the appearance of lateral sidebands. We obtain an excellent agreement with calculations done in the framework of the Huang-Rhys formalism. We conclude that the only relevant parameter for the observation of Acoustic Phonon sidebands is the linewidth of the central zero-Phonon line. At high temperature, the quasi-Lorentzian quantum dot line appears to be fully determined by the Acoustic Phonon sidebands.
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Acoustic Phonon sidebands in the emission line of single inas gaas quantum dots
Physical Review B, 2003Co-Authors: Ivan Favero, Guillaume Cassabois, Robson Ferreira, David Darson, Christophe Voisin, Jérôme Tignon, Claude Delalande, G. Bastard, Ph. Roussignol, J.m. GerardAbstract:We present an experimental and theoretical study of the existence of Acoustic Phonon sidebands in the emission line of single self-assembled InAs/GaAs quantum dots. Temperature-dependent photoluminescence measurements reveal a deviation from a Lorentzian profile with the appearance of lateral sidebands. We obtain an excellent agreement with calculations done in the framework of the Huang-Rhys formalism. We conclude that the only relevant parameter for the observation of Acoustic Phonon sidebands is the linewidth of the central zero-Phonon line. At high temperature, the quasi-Lorentzian quantum dot line appears to be fully determined by the Acoustic Phonon sidebands.
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Efficient Acoustic Phonon broadening in single self-assembled InAs/GaAs quantum dots
Physical Review B: Condensed Matter and Materials Physics, 2002Co-Authors: Claire Kammerer, A. Lemaitre, Guillaume Cassabois, Christophe Voisin, Claude Delalande, Ph. Roussignol, J.m. GerardAbstract:We report systematic temperature-dependent measurements of photoluminescence excitation spectra in single self-assembled InAs/GaAs quantum dots. We studied the increase with temperature of the excited-state homogeneous linewidth for different quantum dots. We found a correlation between the Acoustic Phonon broadening efficiency and the background intensity in the photoluminescence excitation spectra. These results demonstrate the interaction of the discrete quantum dot excited states with a quasicontinuum of states and impose severe limitations on the isolated artificial macroatom scheme for a single quantum dot.
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efficient Acoustic Phonon broadening in single self assembled inas gaas quantum dots
Physical Review B, 2001Co-Authors: Claire Kammerer, A. Lemaitre, Guillaume Cassabois, Christophe Voisin, Claude Delalande, Ph. Roussignol, J.m. GerardAbstract:We report systematic temperature-dependent measurements of photoluminescence excitation spectra in single self-assembled InAs/GaAs quantum dots. We studied the increase with temperature of the excited-state homogeneous linewidth for different quantum dots. We found a correlation between the Acoustic Phonon broadening efficiency and the background intensity in the photoluminescence excitation spectra. These results demonstrate the interaction of the discrete quantum dot excited states with a quasicontinuum of states and impose severe limitations on the isolated artificial macroatom scheme for a single quantum dot.
Alexander A Balandin - One of the best experts on this subject based on the ideXlab platform.
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Acoustic Phonon spectrum engineering in bulk crystals via incorporation of dopant atoms
Applied Physics Letters, 2018Co-Authors: Fariborz Kargar, Elias H Penilla, Ece Aytan, Jacob S Lewis, Javier E Garay, Alexander A BalandinAbstract:We report results of Brillouin—Mandelstam spectroscopy of transparent Al2O3 crystals with Nd dopants. The ionic radius and atomic mass of Nd atoms are distinctively different from those of the host Al atoms. Our results show that even a small concentration of Nd atoms incorporated into the Al2O3 samples produces a profound change in the Acoustic Phonon spectrum. The velocity of the transverse Acoustic Phonons decreases by ∼600 m/s at the Nd density of only ∼0.1%. Interestingly, the decrease in the Phonon frequency and velocity with the doping concentration is non-monotonic. The obtained results, demonstrating that modification of the Acoustic Phonon spectrum can be achieved not only by traditional nanostructuring but also by low-concentration doping, have important implications for thermal management as well as thermoelectric and optoelectronic devices.
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direct observation of confined Acoustic Phonon polarization branches in free standing semiconductor nanowires
Nature Communications, 2016Co-Authors: Fariborz Kargar, Bishwajit Debnath, J P Kakko, Antti Saynatjoki, Harri Lipsanen, Denis L Nika, Roger K Lake, Alexander A BalandinAbstract:Similar to electron waves, the Phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined Acoustic Phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin-Mandelstam light scattering spectroscopy, which reveal multiple (up to ten) confined Acoustic Phonon polarization branches in GaAs nanowires with a diameter as large as 128 nm, at a length scale that exceeds the grey Phonon mean-free path in this material by almost an order-of-magnitude. The dispersion modification and energy scaling with diameter in individual nanowires are in excellent agreement with theory. The Phonon confinement effects result in a decrease in the Phonon group velocity along the nanowire axis and changes in the Phonon density of states. The obtained results can lead to more efficient nanoscale control of Acoustic Phonons, with benefits for nanoelectronic, thermoelectric and spintronic devices.
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Direct observation of confined Acoustic Phonon polarization branches in free-standing semiconductor nanowires
Nature Communications, 2016Co-Authors: Fariborz Kargar, Bishwajit Debnath, J P Kakko, Antti Saynatjoki, Harri Lipsanen, Denis L Nika, Roger K Lake, Alexander A BalandinAbstract:Similar to electron waves, the Phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined Acoustic Phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin—Mandelstam light scattering spectroscopy, which reveal multiple (up to ten) confined Acoustic Phonon polarization branches in GaAs nanowires with a diameter as large as 128 nm, at a length scale that exceeds the grey Phonon mean-free path in this material by almost an order-of-magnitude. The dispersion modification and energy scaling with diameter in individual nanowires are in excellent agreement with theory. The Phonon confinement effects result in a decrease in the Phonon group velocity along the nanowire axis and changes in the Phonon density of states. The obtained results can lead to more efficient nanoscale control of Acoustic Phonons, with benefits for nanoelectronic, thermoelectric and spintronic devices. In nanostructures, Phonon confinement could lead to better control of Phonon-electron coupling and thermal properties. Here, the authors use light scattering spectroscopy to measure Acoustic Phonons confinement in individual free-standing nanowires, their energy dispersion and energy scaling.
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Acoustic Phonon spectrum and thermal transport in nanoporous alumina arrays
arXiv: Mesoscale and Nanoscale Physics, 2015Co-Authors: Fariborz Kargar, Bishwajit Debnath, Roger K Lake, S Ramirez, Hoda Malekpour, Alexander A BalandinAbstract:We report results of a combined investigation of thermal conductivity and Acoustic Phonon spectra in nanoporous alumina membranes with the pore diameter decreasing from D=180 nm to 25 nm. The samples with the hexagonally arranged pores were selected to have the same porosity of ~13%. The Brillouin-Mandelstam spectroscopy measurements revealed bulk-like Phonon spectrum in the samples with D=180-nm pores and spectral features, which were attributed to spatial confinement, in the samples with 25-nm and 40-nm pores. The velocity of the longitudinal Acoustic Phonons was reduced in the samples with smaller pores. Analysis of the experimental data and calculated Phonon dispersion suggests that both Phonon-boundary scattering and Phonon spatial confinement affect heat conduction in membranes with the feature sizes D<40 nm.
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Acoustic Phonon propagation in rectangular semiconductor nanowires with elastically dissimilar barriers
Physical Review B, 2005Co-Authors: E P Pokatilov, Denis L Nika, Alexander A BalandinAbstract:We have theoretically studied Acoustic Phonon spectra and Phonon propagation in rectangular nanowires embedded within elastically dissimilar materials. As example systems, we have considered GaN nanowires with AlN and plastic barrier layers. It has been established that the Acoustically mismatched barriers dramatically influence the quantized Phonon spectrum of the nanowires. The barriers with lower sound velocity compress the Phonon energy spectrum and reduce the Phonon group velocities in the nanowire. The barriers with higher sound velocity have an opposite effect. The physical origin of this effect is related to redistribution of the elastic deformations in the Acoustically mismatched nanowires. In the case of the “Acoustically slow” barriers, the elastic deformation waves are squeezed in the barrier layer. The effect predicted for the nanowires embedded with elastically dissimilar materials could be used for reengineering Phonon spectrum in nanostructures.
Guillaume Cassabois - One of the best experts on this subject based on the ideXlab platform.
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Acoustic Phonon sidebands in the emission line of single InAs/GaAs quantum dots
Physical Review B, 2003Co-Authors: Ivan Favero, Guillaume Cassabois, Robson Ferreira, David Darson, Christophe Voisin, Jérôme Tignon, Claude Delalande, G. Bastard, Ph. Roussignol, J.m. GerardAbstract:We present an experimental and theoretical study of the existence of Acoustic Phonon sidebands in the emission line of single self-assembled InAs/GaAs quantum dots. Temperature-dependent photoluminescence measurements reveal a deviation from a Lorentzian profile with the appearance of lateral sidebands. We obtain an excellent agreement with calculations done in the framework of the Huang-Rhys formalism. We conclude that the only relevant parameter for the observation of Acoustic Phonon sidebands is the linewidth of the central zero-Phonon line. At high temperature, the quasi-Lorentzian quantum dot line appears to be fully determined by the Acoustic Phonon sidebands.
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Acoustic Phonon sidebands in the emission line of single inas gaas quantum dots
Physical Review B, 2003Co-Authors: Ivan Favero, Guillaume Cassabois, Robson Ferreira, David Darson, Christophe Voisin, Jérôme Tignon, Claude Delalande, G. Bastard, Ph. Roussignol, J.m. GerardAbstract:We present an experimental and theoretical study of the existence of Acoustic Phonon sidebands in the emission line of single self-assembled InAs/GaAs quantum dots. Temperature-dependent photoluminescence measurements reveal a deviation from a Lorentzian profile with the appearance of lateral sidebands. We obtain an excellent agreement with calculations done in the framework of the Huang-Rhys formalism. We conclude that the only relevant parameter for the observation of Acoustic Phonon sidebands is the linewidth of the central zero-Phonon line. At high temperature, the quasi-Lorentzian quantum dot line appears to be fully determined by the Acoustic Phonon sidebands.
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Efficient Acoustic Phonon broadening in single self-assembled InAs/GaAs quantum dots
Physical Review B: Condensed Matter and Materials Physics, 2002Co-Authors: Claire Kammerer, A. Lemaitre, Guillaume Cassabois, Christophe Voisin, Claude Delalande, Ph. Roussignol, J.m. GerardAbstract:We report systematic temperature-dependent measurements of photoluminescence excitation spectra in single self-assembled InAs/GaAs quantum dots. We studied the increase with temperature of the excited-state homogeneous linewidth for different quantum dots. We found a correlation between the Acoustic Phonon broadening efficiency and the background intensity in the photoluminescence excitation spectra. These results demonstrate the interaction of the discrete quantum dot excited states with a quasicontinuum of states and impose severe limitations on the isolated artificial macroatom scheme for a single quantum dot.
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efficient Acoustic Phonon broadening in single self assembled inas gaas quantum dots
Physical Review B, 2001Co-Authors: Claire Kammerer, A. Lemaitre, Guillaume Cassabois, Christophe Voisin, Claude Delalande, Ph. Roussignol, J.m. GerardAbstract:We report systematic temperature-dependent measurements of photoluminescence excitation spectra in single self-assembled InAs/GaAs quantum dots. We studied the increase with temperature of the excited-state homogeneous linewidth for different quantum dots. We found a correlation between the Acoustic Phonon broadening efficiency and the background intensity in the photoluminescence excitation spectra. These results demonstrate the interaction of the discrete quantum dot excited states with a quasicontinuum of states and impose severe limitations on the isolated artificial macroatom scheme for a single quantum dot.
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Polariton-Acoustic-Phonon interaction in a semiconductor microcavity
Physical Review B, 2000Co-Authors: Guillaume Cassabois, Claude Delalande, A. L. C. Triques, F. Bogani, Philippe Roussignol, Carlo PiermarocchiAbstract:The broadening of polariton lines by Acoustic Phonons is investigated in a semiconductor microcavity by means of interferometric correlation measurements with subpicosecond resolution. A decrease of the polariton-Acoustic Phonon coupling is clearly observed for the lower polariton branch as one approaches the resonance between exciton and photon states. This behavior cannot be explained in terms of a semiclassical linear dispersion theory but requires a full quantum description of the microcavity in the strong-coupling regime.
Claude Delalande - One of the best experts on this subject based on the ideXlab platform.
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Acoustic Phonon sidebands in the emission line of single InAs/GaAs quantum dots
Physical Review B, 2003Co-Authors: Ivan Favero, Guillaume Cassabois, Robson Ferreira, David Darson, Christophe Voisin, Jérôme Tignon, Claude Delalande, G. Bastard, Ph. Roussignol, J.m. GerardAbstract:We present an experimental and theoretical study of the existence of Acoustic Phonon sidebands in the emission line of single self-assembled InAs/GaAs quantum dots. Temperature-dependent photoluminescence measurements reveal a deviation from a Lorentzian profile with the appearance of lateral sidebands. We obtain an excellent agreement with calculations done in the framework of the Huang-Rhys formalism. We conclude that the only relevant parameter for the observation of Acoustic Phonon sidebands is the linewidth of the central zero-Phonon line. At high temperature, the quasi-Lorentzian quantum dot line appears to be fully determined by the Acoustic Phonon sidebands.
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Acoustic Phonon sidebands in the emission line of single inas gaas quantum dots
Physical Review B, 2003Co-Authors: Ivan Favero, Guillaume Cassabois, Robson Ferreira, David Darson, Christophe Voisin, Jérôme Tignon, Claude Delalande, G. Bastard, Ph. Roussignol, J.m. GerardAbstract:We present an experimental and theoretical study of the existence of Acoustic Phonon sidebands in the emission line of single self-assembled InAs/GaAs quantum dots. Temperature-dependent photoluminescence measurements reveal a deviation from a Lorentzian profile with the appearance of lateral sidebands. We obtain an excellent agreement with calculations done in the framework of the Huang-Rhys formalism. We conclude that the only relevant parameter for the observation of Acoustic Phonon sidebands is the linewidth of the central zero-Phonon line. At high temperature, the quasi-Lorentzian quantum dot line appears to be fully determined by the Acoustic Phonon sidebands.
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Efficient Acoustic Phonon broadening in single self-assembled InAs/GaAs quantum dots
Physical Review B: Condensed Matter and Materials Physics, 2002Co-Authors: Claire Kammerer, A. Lemaitre, Guillaume Cassabois, Christophe Voisin, Claude Delalande, Ph. Roussignol, J.m. GerardAbstract:We report systematic temperature-dependent measurements of photoluminescence excitation spectra in single self-assembled InAs/GaAs quantum dots. We studied the increase with temperature of the excited-state homogeneous linewidth for different quantum dots. We found a correlation between the Acoustic Phonon broadening efficiency and the background intensity in the photoluminescence excitation spectra. These results demonstrate the interaction of the discrete quantum dot excited states with a quasicontinuum of states and impose severe limitations on the isolated artificial macroatom scheme for a single quantum dot.
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efficient Acoustic Phonon broadening in single self assembled inas gaas quantum dots
Physical Review B, 2001Co-Authors: Claire Kammerer, A. Lemaitre, Guillaume Cassabois, Christophe Voisin, Claude Delalande, Ph. Roussignol, J.m. GerardAbstract:We report systematic temperature-dependent measurements of photoluminescence excitation spectra in single self-assembled InAs/GaAs quantum dots. We studied the increase with temperature of the excited-state homogeneous linewidth for different quantum dots. We found a correlation between the Acoustic Phonon broadening efficiency and the background intensity in the photoluminescence excitation spectra. These results demonstrate the interaction of the discrete quantum dot excited states with a quasicontinuum of states and impose severe limitations on the isolated artificial macroatom scheme for a single quantum dot.
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Polariton-Acoustic-Phonon interaction in a semiconductor microcavity
Physical Review B, 2000Co-Authors: Guillaume Cassabois, Claude Delalande, A. L. C. Triques, F. Bogani, Philippe Roussignol, Carlo PiermarocchiAbstract:The broadening of polariton lines by Acoustic Phonons is investigated in a semiconductor microcavity by means of interferometric correlation measurements with subpicosecond resolution. A decrease of the polariton-Acoustic Phonon coupling is clearly observed for the lower polariton branch as one approaches the resonance between exciton and photon states. This behavior cannot be explained in terms of a semiclassical linear dispersion theory but requires a full quantum description of the microcavity in the strong-coupling regime.
Christophe Voisin - One of the best experts on this subject based on the ideXlab platform.
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Acoustic Phonon sidebands in the emission line of single InAs/GaAs quantum dots
Physical Review B, 2003Co-Authors: Ivan Favero, Guillaume Cassabois, Robson Ferreira, David Darson, Christophe Voisin, Jérôme Tignon, Claude Delalande, G. Bastard, Ph. Roussignol, J.m. GerardAbstract:We present an experimental and theoretical study of the existence of Acoustic Phonon sidebands in the emission line of single self-assembled InAs/GaAs quantum dots. Temperature-dependent photoluminescence measurements reveal a deviation from a Lorentzian profile with the appearance of lateral sidebands. We obtain an excellent agreement with calculations done in the framework of the Huang-Rhys formalism. We conclude that the only relevant parameter for the observation of Acoustic Phonon sidebands is the linewidth of the central zero-Phonon line. At high temperature, the quasi-Lorentzian quantum dot line appears to be fully determined by the Acoustic Phonon sidebands.
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Acoustic Phonon sidebands in the emission line of single inas gaas quantum dots
Physical Review B, 2003Co-Authors: Ivan Favero, Guillaume Cassabois, Robson Ferreira, David Darson, Christophe Voisin, Jérôme Tignon, Claude Delalande, G. Bastard, Ph. Roussignol, J.m. GerardAbstract:We present an experimental and theoretical study of the existence of Acoustic Phonon sidebands in the emission line of single self-assembled InAs/GaAs quantum dots. Temperature-dependent photoluminescence measurements reveal a deviation from a Lorentzian profile with the appearance of lateral sidebands. We obtain an excellent agreement with calculations done in the framework of the Huang-Rhys formalism. We conclude that the only relevant parameter for the observation of Acoustic Phonon sidebands is the linewidth of the central zero-Phonon line. At high temperature, the quasi-Lorentzian quantum dot line appears to be fully determined by the Acoustic Phonon sidebands.
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Efficient Acoustic Phonon broadening in single self-assembled InAs/GaAs quantum dots
Physical Review B: Condensed Matter and Materials Physics, 2002Co-Authors: Claire Kammerer, A. Lemaitre, Guillaume Cassabois, Christophe Voisin, Claude Delalande, Ph. Roussignol, J.m. GerardAbstract:We report systematic temperature-dependent measurements of photoluminescence excitation spectra in single self-assembled InAs/GaAs quantum dots. We studied the increase with temperature of the excited-state homogeneous linewidth for different quantum dots. We found a correlation between the Acoustic Phonon broadening efficiency and the background intensity in the photoluminescence excitation spectra. These results demonstrate the interaction of the discrete quantum dot excited states with a quasicontinuum of states and impose severe limitations on the isolated artificial macroatom scheme for a single quantum dot.
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efficient Acoustic Phonon broadening in single self assembled inas gaas quantum dots
Physical Review B, 2001Co-Authors: Claire Kammerer, A. Lemaitre, Guillaume Cassabois, Christophe Voisin, Claude Delalande, Ph. Roussignol, J.m. GerardAbstract:We report systematic temperature-dependent measurements of photoluminescence excitation spectra in single self-assembled InAs/GaAs quantum dots. We studied the increase with temperature of the excited-state homogeneous linewidth for different quantum dots. We found a correlation between the Acoustic Phonon broadening efficiency and the background intensity in the photoluminescence excitation spectra. These results demonstrate the interaction of the discrete quantum dot excited states with a quasicontinuum of states and impose severe limitations on the isolated artificial macroatom scheme for a single quantum dot.
