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144 results on '"Lafosse, X."'

1. Quartic scaling of sound attenuation with frequency in vitreous silica

Author

Wang, P. -J., Huynh, A., Hung, T. -C., Sheu, J. -K., Lafosse, X., Lemaitre, A., Perrin, B., Rufflé, B., Vacher, R., Sun, C. -K., and Foret, M.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Many theories predict a quartic acoustic attenuation increase at sub-THz frequencies in glassy media for the excess vibrational modes known as the boson peak anomaly. Here by introducing phase-sensitive acoustic spectroscopy techniques with a THz bandwidth, we investigate the acoustic properties of vitreous silica at 15 and 300K in the crucial but unexplored sub-THz gap region below the boson peak. Our results indicate a strong negative dispersion starting at \SI{500}{GHz} and the onset of an athermal quartic-frequency-scaling acoustic attenuation term, which emerges above all other thermal losses., Comment: 4 figures, 11 pages

Published
2023

2. Intersubband polariton-polariton scattering in a dispersive microcavity

Author

Knorr, M., Manceau, J. M., Mornhinweg, J., Nespolo, J., Biasiol, G., Tran, N. L., Malerba, M., Goulain, P., Lafosse, X., Jeannin, M., Stefinger, M., Carusotto, I., Lange, C., Colombelli, R., and Huber, R.

Subjects
Physics - Optics, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

The ultrafast scattering dynamics of intersubband polaritons in dispersive cavities embedding GaAs/AlGaAs quantum wells are studied directly within their band structure using a non-collinear pump-probe geometry with phase-stable mid-infrared pulses. Selective excitation of the lower polariton at a frequency of ~25 THz and at a finite in-plane momentum, $k_{||}$, leads to the emergence of a narrowband maximum in the probe reflectivity at $k_{||}=0$. A quantum mechanical model identifies the underlying microscopic process as stimulated coherent polariton-polariton scattering. These results mark an important milestone towards quantum control and bosonic lasing in custom-tailored polaritonic systems in the mid and far-infrared.

Published
2022
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3. Competition between horizontal and vertical polariton lasing in planar microcavities

Author

Jamadi, O., Reveret, F., Solnyshkov, D., Disseix, P., Leymarie, J., Mallet-Dida, L., Brimont, C., Guillet, T., Lafosse, X., Bouchoule, S., Semond, F., Leroux, M., Zuniga-Perez, J., and Malpuech, G.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Optics
Abstract

Planar microcavities filled with active materials containing excitonic resonances host radiative exciton-polariton (polariton) modes with in-plane wave vectors within the light cone. They also host at least one mode guided in the cavity plane by total internal reflection and which is not radiatively coupled to the vacuum modes except through defects or sample edges. We show that polariton lasing mediated by polariton stimulated scattering can occur concomitantly in both types of modes in a microcavity. By adjusting the detuning between the exciton and the radiative photon mode one can favor polariton lasing either in the radiative or in the guided modes. Our results suggest that the competition between these two types of polariton lasing modes may have played a role in many previous observations of polariton lasing and polariton Bose Einstein condensation.

Published
2018
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4. Polariton condensation phase diagram in wide bandgap planar microcavities: GaN versus ZnO

Author

Jamadi, O., Réveret, F., Mallet, E., Disseix, P., Médard, F., Mihailovic, M., Solnyshkov, D., Malpuech, G., Leymarie, J., Bouchoule, S., Lafosse, X., Li, F., Leroux, M., Semond, F., and Zuniga-Perez, J.

Subjects
Condensed Matter - Materials Science
Abstract

GaN and ZnO microcavities have been grown on patterned silicon substrate. Thanks to a common platform these microcavities share similar photonic properties with large quality factors and low photonic disorder which gives the possibility to determine the optimal spot diameter and to realize a complete comparative phase diagram study. Both systems have been investigated under the same experimental condition. Experimental results are well reproduced by simulation using Boltzmann equations. Lower polariton lasing threshold has been measured at low temperature in the ZnO microcavity as expected due to a larger Rabi splitting. However the threshold is strongly impacted by LO phonons through phonon-assisted polariton relaxation. We observe and discuss this effect as a function of temperature and detuning. Finally the polariton lasing threshold at room temperature is quite similar in both microcavities. This study highlights polariton relaxation mechanism and their importance for threshold optimization.

Published
2015
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5. Field-effect control of superconductivity and Rashba spin-orbit coupling in top-gated LaAlO3/SrTiO3 devices

Author

Hurand, S., Jouan, A., Feuillet-Palma, C., Singh, G., Biscaras, J., Lesne, E., Reyen, N., Barthelemy, A., Bibes, M., Ulysse, C., Lafosse, X., Pannetier-Lecoeur, M., Caprara, S., Grilli, M., Lesueur, J., and Bergeal, N.

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Materials Science
Abstract

The recent development in the fabrication of artificial oxide heterostructures opens new avenues in the field of quantum materials by enabling the manipulation of the charge, spin and orbital degrees of freedom. In this context, the discovery of two-dimensional electron gases (2-DEGs) at LAlO3/SrTiO3 interfaces, which exhibit both superconductivity and strong Rashba spin-orbit coupling (SOC), represents a major breakthrough. Here, we report on the realisation of a field-effect LaAlO3/SrTiO3 device, whose physical properties, including superconductivity and SOC, can be tuned over a wide range by a top-gate voltage. We derive a phase diagram, which emphasises a field-effect-induced superconductor-to-insulator quantum phase transition. Magneto-transport measurements indicate that the Rashba coupling constant increases linearly with electrostatic doping. Our results pave the way for the realisation of mesoscopic devices, where these two properties can be manipulated on a local scale by means of top-gates.

Published
2015

6. Patterned silicon substrates: a common platform for room temperature GaN and ZnO polariton lasers

Author

Zuniga-Perez, J., Mallet, E., Hahe, R., Rashid, M. J., Bouchoule, S., Brimont, C., Disseix, P., Duboz, J. Y., Gommé, G., Guillet, T., Jamadi, O., Lafosse, X., Leroux, M., Leymarie, J., Li, Feng, Réveret, F., and Semond, F.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Optics
Abstract

A new platform for fabricating polariton lasers operating at room temperature is introduced: nitride-based distributed Bragg reflectors epitaxially grown on patterned silicon substrates. The patterning allows for an enhanced strain relaxation thereby enabling to stack a large number of crack-free AlN/AlGaN pairs and achieve cavity quality factors of several thousands with a large spatial homogeneity. GaN and ZnO active regions are epitaxially grown thereon and the cavities are completed with top dielectric Bragg reflectors. The two structures display strong-coupling and polariton lasing at room temperature and constitute an intermediate step in the way towards integrated polariton devices.

Published
2014
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7. Controlling spontaneous emission with plasmonic optical patch antennas

Author

Belacel, C., Habert, B., Bigourdan, F., Marquier, F., Hugonin, J. -P., de Vasconcellos, S. Michaelis, Lafosse, X., Coolen, L., Schwob, C., Javaux, C., Dubertret, B., Greffet, J. -J., Senellart, P., and Maitre, A.

Subjects
Quantum Physics, Condensed Matter - Other Condensed Matter, Physics - Optics
Abstract

We experimentally demonstrate the control of the spontaneous emission rate and the radiation pattern of colloidal quantum dots deterministically positioned in a plasmonic patch antenna. The antenna consists of a thin gold microdisk 30 nm above a thick gold layer. The emitters are shown to radiate through the entire patch antenna in a highly directional and vertical radiation pattern. Strong acceleration of spontaneous emission is observed, depending of the antenna size. Considering the double dipole structure of the emitters, this corresponds to a Purcell factor up to 80 for dipoles perpendicular to the disk.

Published
2012
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8. LO-phonon assisted polariton lasing in a ZnO based microcavity

Author

Orosz, L., Réveret, F., Médard, F., Disseix, P., Leymarie, J., Mihailovic, M., Solnyshkov, D., Malpuech, G., Zuniga-Pérez, J., Semond, F., Leroux, M., Bouchoule, S., Lafosse, X., Mexis, M., Brimont, C., and Guillet, T.

Subjects
Condensed Matter - Materials Science
Abstract

Polariton relaxation mechanisms are analysed experimentally and theoretically in a ZnO-based polariton laser. A minimum lasing threshold is obtained when the energy difference between the exciton reservoir and the bottom of the lower polariton branch is resonant with the LO phonon energy. Tuning off this resonance increases the threshold, and exciton-exciton scattering processes become involved in the polariton relaxation. These observations are qualitatively reproduced by simulations based on the numerical solution of the semi-classical Boltzmann equations.

Published
2011
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12. Confined Visible Optical Tamm States

Author

Feng, F., Ouaret, K., Portalupi, S., Lafosse, X., Nasilovski, M., de Marcillac, W. Daney, Frigerio, J.-M., Schwob, C., Dubertret, B., Maître, A., Senellart, P., and Coolen, L.

Published
2016
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13. Stimulated Non-Collinear Intersubband Polariton-Polariton Scattering in a Dispersive Multi-THz Microcavity

Author

Knorr, M., primary, Manceau, J.M., additional, Mornhinweg, J., additional, Nespolo, J., additional, Biasiol, G., additional, Tran, N.L., additional, Malerba, M., additional, Goulain, P., additional, Lafosse, X., additional, Jeannin, M., additional, Stefinger, M., additional, Carusotto, I., additional, Lange, C., additional, Colombelli, R., additional, and Huber, R., additional

Published
2022
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14. Intersubband Polariton-Polariton Scattering in a Dispersive Microcavity

Author

Knorr, M., primary, Manceau, J. M., additional, Mornhinweg, J., additional, Nespolo, J., additional, Biasiol, G., additional, Tran, N. L., additional, Malerba, M., additional, Goulain, P., additional, Lafosse, X., additional, Jeannin, M., additional, Stefinger, M., additional, Carusotto, I., additional, Lange, C., additional, Colombelli, R., additional, and Huber, R., additional

Published
2022
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20. ZnO and Al-doped ZnO Sol-Gel Properties

Author

Moussa, N. Ben, primary, Lajnef, M., additional, Jebari, N., additional, Mahut, F., additional, Bayle, F., additional, Villebasse, C., additional, Durnez, A., additional, Dupuis, C., additional, Maillard, F., additional, Lafosse, X., additional, Chtourou, R., additional, and Herth, E., additional

Published
2021
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25. High reflectance dielectric distributed Bragg reflectors for near ultra-violet planar microcavities: SiO2/HfO2 versus SiO2/SiNx.

Author

Réveret, F., Bignet, L., Zhigang, W., Lafosse, X., Patriarche, G., Disseix, P., Médard, F., Mihailovic, M., Leymarie, J., Zúñiga-Pérez, J., and Bouchoule, S.

Subjects
LIGHTING reflectors, OPTICAL properties, INTERFACIAL roughness, REFLECTANCE, ABSORPTION coefficients
Abstract

SiO2/SiNx and SiO2/HfO2 distributed Bragg reflectors for the ultra-violet (λ= 360nm-380nm) are compared through their structural and optical properties. The SiO2/HfO2 system exhibits a lower interface roughness, higher reflectance, larger stop band, and lower penetration depth than SiO2 SiNx. A cavity quality factor of 3700 at about 360 nm is measured on a passive SiO2/HfO2-based planar microcavity. Compared with values obtained in the literature for the near UV range, the latter is rather large. Micro-reflectance measurements have been performed on a series of passive microcavities with increasing cavity thickness to determine the residual absorption in the SiO2 and HfO2 layers. Absorption coefficients of 30 (k = 0.86 x 10-4) and 160 cm-1 (k = 4.59 x 10-4) near λ ~ 360 nm have been extracted for SiO2 and HfO2, respectively. Transfer-matrix simulations taking into account the residual absorption show that microcavity quality factors up to 8000 can be expected at 360-380nm with this material system. Such values are well-suited for the fabrication of UV-vertical cavity surface emitting lasers or microcavity polariton lasers operating at room temperature. [ABSTRACT FROM AUTHOR]

Published
2016
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26. Temperature dependence of hypersound attenuation in silica films via picosecond acoustics

Author

FORET, Marie, Huynh, A., Peronne, E., RUFFLE, Benoit, Perrin, B., Lafosse, X., Lemaitre, A., VACHER, Rene, Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Centre de Nanosciences et de Nanotechnologies [Marcoussis] (C2N), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Lifa Zhang (Nanjing Normal University, and Conference Chair)

Subjects
[PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other]
Abstract

We reinvestigate sound dispersion and attenuation in a SiO2 layer as a function of temperature over the range 20–300 K by picosecond acoustics [1]. A pulse-echo scheme is used, where a broadband strain-pulse (centered at 120 GHz) is detected in an Al transducer after propagating back and forth through the SiO2 layer. The acoustic attenuation coefficient α within the SiO2 layer is evaluated by fitting the echoes to a mismatch model including an effective local law for the frequency dependence of attenuation over the band of the pulse. In this way, the T dependence of α in SiO2 layers could be extracted in this work for the first time. Results are found to follow rather well a model combining coupling to thermally activated relaxation mechanisms and interactions with thermal vibrations. This leads to a non-trivial variation of the attenuation coefficient with frequency and temperature. The number density of relaxing defects in the SiO2 layer is found to be slightly higher than that in bulk v-SiO2. In contrast, similar anharmonic contribution to acoustic absorption is observed in both systems. The velocity variations are also measured and are compared to the dynamical velocity changes deduced from the sound attenuation.

Published
2018

27. Competition between horizontal and vertical polariton lasing in planar microcavities

Author

Jamadi, O., primary, Réveret, F., additional, Solnyshkov, D., additional, Disseix, P., additional, Leymarie, J., additional, Mallet-Dida, L., additional, Brimont, C., additional, Guillet, T., additional, Lafosse, X., additional, Bouchoule, S., additional, Semond, F., additional, Leroux, M., additional, Zuniga-Perez, J., additional, and Malpuech, G., additional

Published
2019
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31. Temperature dependence of hypersound attenuation in silica films via ultrafast acoustics

Author

Peronne, E., Huynh, A., Gingreau, C., Lafosse, X., Lemaitre, A., Perrin, B., FORET, Marie, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Centre de Nanosciences et de Nanotechnologies [Marcoussis] (C2N), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and A J (Tony) Kent (Conference Chair)

Subjects
[PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other]
Published
2015

32. Acoustic attenuation and velocity measurements in vitreous silica by ps laser ultrasonics

Author

Huynh, A., Gingreau, C., Lafosse, X., Lemaitre, A., Peronne, E., Perrin, B., FORET, Marie, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre de Nanosciences et de Nanotechnologies [Marcoussis] (C2N), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and European Physical Society EPS and the French Physical Society SFP (Condensed Matter Divisions)

Subjects
[PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2014

34. Polariton condensation phase diagram in wide-band-gap planar microcavities: GaN versus ZnO

Author

Jamadi, O., primary, Réveret, F., additional, Mallet, E., additional, Disseix, P., additional, Médard, F., additional, Mihailovic, M., additional, Solnyshkov, D., additional, Malpuech, G., additional, Leymarie, J., additional, Lafosse, X., additional, Bouchoule, S., additional, Li, F., additional, Leroux, M., additional, Semond, F., additional, and Zuniga-Perez, J., additional

Published
2016
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35. Generation of new spatial and temporal coherent states using VeCSEL technology : VORTEX, high order Laguerre-Gauss mode, continuum source, spin

Author

Garnache, A., Sellahi, M., Seghilani, M., Paquet, R., Blin, S., Myara, M., Sagnes, I., Beaudoin, G., Lafosse, X., Legratiet, L., Lalanne, P., Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Térahertz, hyperfréquence et optique (TéHO), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), and Centre National de la Recherche Scientifique (CNRS)

Subjects
ComputingMilieux_MISCELLANEOUS, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience

Published
2014

36. Miroir de Bragg concave à base de cristaux photoniques, pour lasers à semi-conducteurs de haute cohérence à cavité externe

Author

Seghilani, M., Sellahi, M., Devautour, M., Sagnes, I., Beaudoin, G., Lafosse, X., Legratiet, L., Lalanne, P., Myara, M., Garnache, A., Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Térahertz, hyperfréquence et optique (TéHO), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Eric, Dauverchain

Subjects
[SPI.TRON] Engineering Sciences [physics]/Electronics, ComputingMilieux_MISCELLANEOUS, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience

Published
2013

37. A hybrid Photonic Crystal−based semiconductor Bragg mirror: A low loss functional mirror for high−Q external cavity lasers

Author

Seghilani, M., Sellahi, M., Sagnes, I., Beaudoin, G., Lafosse, X., Legratiet, L., Lalanne, P., Devautour, M., Myara, M., Garnache, A., Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Térahertz, hyperfréquence et optique (TéHO), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
ComputingMilieux_MISCELLANEOUS, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience

Published
2013

38. Improvement of the thermal properties of semiconductor chips at 850 nm

Author

Gozhyk, I., Beaudoin, G., Janicot, S., Lafosse, X., Garnache, A., Sagnes, I., Georges, P., Lucas−Leclin, G., Eric, Dauverchain, Laboratoire de Photonique Quantique et Moléculaire (LPQM), École normale supérieure - Cachan (ENS Cachan)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Térahertz, hyperfréquence et optique (TéHO), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
ComputingMilieux_MISCELLANEOUS, [SPI.TRON] Engineering Sciences [physics]/Electronics, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience

Published
2013

39. Control of new spatial, temporal and polarization coherent light states with VeCSEL: VORTEX, continuum, THz, spin

Author

Garnache, A., Sellahi, M., Seghilani, M., Paquet, R., Blin, S., Myara, M., Sagnes, I., Beaudoin, G., Lafosse, X., Legratiet, L., Lalanne, P., Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Térahertz, hyperfréquence et optique (TéHO), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), and Centre National de la Recherche Scientifique (CNRS)

Subjects
ComputingMilieux_MISCELLANEOUS, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience

Published
2013

43. Confined Visible Optical Tamm States

Author

Feng, F., primary, Ouaret, K., additional, Portalupi, S., additional, Lafosse, X., additional, Nasilovski, M., additional, de Marcillac, W. Daney, additional, Frigerio, J.-M., additional, Schwob, C., additional, Dubertret, B., additional, Maître, A., additional, Senellart, P., additional, and Coolen, L., additional

Published
2015
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44. Field-effect control of superconductivity and Rashba spin-orbit coupling in top-gated LaAlO3/SrTiO3 devices

Author

Hurand, S., primary, Jouan, A., additional, Feuillet-Palma, C., additional, Singh, G., additional, Biscaras, J., additional, Lesne, E., additional, Reyren, N., additional, Barthélémy, A., additional, Bibes, M., additional, Villegas, J. E., additional, Ulysse, C., additional, Lafosse, X., additional, Pannetier-Lecoeur, M., additional, Caprara, S., additional, Grilli, M., additional, Lesueur, J., additional, and Bergeal, N., additional

Published
2015
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45. Coupling colloidal nanocrystals to Optical Tamm plasmons

Author

Feng, F., primary, Portalupi, S., additional, Lafosse, X., additional, Raj Dhawan, A., additional, Daney de Marcillac, W., additional, Frigerio, J.-M, additional, Schwob, C., additional, Dubertret, B., additional, Maitre, A., additional, Senellart, P., additional, and Coolen, L., additional

Published
2015
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48. Patterned silicon substrates: A common platform for room temperature GaN and ZnO polariton lasers

Author

Zuniga-Perez, J., primary, Mallet, E., additional, Hahe, R., additional, Rashid, M. J., additional, Bouchoule, S., additional, Brimont, C., additional, Disseix, P., additional, Duboz, J. Y., additional, Gommé, G., additional, Guillet, T., additional, Jamadi, O., additional, Lafosse, X., additional, Leroux, M., additional, Leymarie, J., additional, Li, Feng, additional, Réveret, F., additional, and Semond, F., additional

Published
2014
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