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Théorie du rayonnement matière et phénomènes quantiques
(27) Production(s) de l'année 2017
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Strong coupling between a plasmonic waveguide and graphene surface plasmons
Auteur(s): Ben Rhouma Maha, Oueslati Meherzi, Guizal B.
(Article) Publié:
Journal Of The Optical Society Of America B, vol. 34 p.884-890 (2017)
Ref HAL: hal-01501931_v1
DOI: 10.1364/JOSAB.34.000884
WoS: 000399320300023
Exporter : BibTex | endNote
3 Citations
Résumé: We study the coupling between surface plasmons of a doped graphene sheet and those of a metal-like/dielectric/ metal-like plasmonic waveguide. In order to allow such a coupling, the metal-like media are chosen to be doped semiconductors with plasma energies close to the Fermi level of the doped graphene. We derive and compute numerically the full dispersion relation and study in detail the characteristics of the hybrid modes emerging from strong coupling.
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Near-Field Radiative Heat Transfer under Temperature Gradients and Conductive Transfer
Auteur(s): Jin Weiliang, Messina R., Rodriguez Alejandro W.
(Article) Publié:
Zeitschrift Für Naturforschung A, vol. 72 p.141-149 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01499902_v1
DOI: 10.1515/zna-2016-0375
WoS: WOS:000394230400007
Exporter : BibTex | endNote
Résumé: We describe a recently developed formulation of coupled conductive and radiative heat transfer (RHT) between objects separated by nanometric, vacuum gaps. Our results rely on analytical formulas of RHT between planar slabs (based on the scattering-matrix method) as well as a general formulation of RHT between arbitrarily shaped bodies (based on the fluctuating–volume current method), which fully captures the existence of temperature inhomogeneities. In particular, the impact of RHT on conduction, and vice versa, is obtained via self-consistent solutions of the Fourier heat equation and Maxwell’s equations. We show that in materials with low thermal conductivities (e.g. zinc oxides and glasses), the interplay of conduction and RHT can strongly modify heat exchange, exemplified forinstance by the presence of large temperature gradients and saturating flux rates at short (nanometric) distances. More generally, we show that the ability to tailor the temperature distribution of an object can modify the behaviour of RHT with respect to gap separations, e.g. qualitatively changing the asymptotic scaling at short separations from quadratic to linear or logarithmic. Our results could be relevant to the interpretation of both past and future experimental measurementsof RHT at nanometric distances.
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Strong Thermal and Electrostatic Manipulation of the Casimir Force in Graphene Multilayers
Auteur(s): Abbas C., Guizal B., Antezza M.
(Article) Publié:
Physical Review Letters, vol. 118 p.126101 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01494732_v1
DOI: 10.1103/PhysRevLett.118.126101
WoS: 000397804300011
Exporter : BibTex | endNote
10 Citations
Résumé: We show that graphene-dielectric multilayers give rise to an unusual tunability of the Casimir-Lifshitz forces and allow to easily realize completely different regimes within the same structure. Concerning thermal effects, graphene-dielectric multilayers take advantage of the anomalous features predicted forisolated suspended graphene sheets, even though they are considerably affected by the presence of the dielectric substrate. They can also achieve the anomalous nonmonotonic thermal metallic behavior by increasing the graphene sheets density and their Fermi level. In addition to a strong thermal modulation occurring at short separations, in a region where the force is orders of magnitude larger than the one occurring at large distances, the force can be also adjusted by varying the number of graphene layers as well as their Fermi levels, allowing for relevant force amplifications which can be tuned, very rapidly and in situ, by simply applying an electric potential. Our predictions can be relevant for both Casimir experiments and micro- or nanoelectromechanical systems and in new devices for technological applications.
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Radiative heat transfer between metallic gratings using Fourier modal method with adaptive spatial resolution
Auteur(s): Messina R., Noto A., Guizal B., Antezza M.
(Article) Publié:
Physical Review B, vol. 95 p.125404 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01482013_v1
DOI: 10.1103/PhysRevB.95.125404
WoS: 000396010400005
Exporter : BibTex | endNote
25 Citations
Résumé: We calculate the radiative heat transfer between two identical metallic one-dimensional lamellar gratings. To this aim we present and exploit a modification to the widely used Fourier modal method, known as adaptive spatial resolution, based on a stretch of the coordinate associated with the periodicity of the grating. We first show that this technique dramatically improves the rate of convergence when calculating the heat flux, allowing us to explore smaller separations. We then present a study of heat flux as a function of the grating height, highlighting a remarkable amplification of the exchanged energy, ascribed to the appearance of spoof-plasmon modes, whose behavior is also spectrally investigated. Differently from previous works, our method allows us to explore a range of grating heights extending over several orders of magnitude. By comparing our results to recent studies we find a consistent quantitative disagreement with some previously obtained results going up to 50%. In some cases, this disagreement is explained in terms of an incorrect connection between the reflection operators of the two gratings.
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Many body heat radiation and heat transfer in the presence of a non-absorbing background medium
Auteur(s): Boris Muller, Roberta Incardone, Antezza M., Thorsten Emig, Matthias Kruger
(Article) Publié:
Physical Review B, vol. 95 p.085413 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01464078_v1
DOI: 10.1103/PhysRevB.95.085413
WoS: 000393590900004
Exporter : BibTex | endNote
22 Citations
Résumé: Heat radiation and near-field radiative heat transfer can be strongly manipulated by adjusting geometrical shapes, optical properties, or the relative positions of the objects involved. Typically, these objects are considered as embedded in vacuum. By applying the methods of fluctuational electrodynamics, we derive general closed-form expressions for heat radiation and heat transfer in a system of N arbitrary objects embedded in a passive nonabsorbing background medium. Taking into account the principle of reciprocity, we explicitly prove the symmetry and positivity of transfer in any such system. Regarding applications, we find that the heat radiation of a sphere as well as the heat transfer between two parallel plates is strongly enhanced by the presence of a background medium. Regarding near- and far-field transfer through a gas like air, we show that a microscopic model (based on gas particles) and a macroscopic model (using a dielectric contrast) yield identical results. We also compare the radiative transfer through a medium like air and the energy transfer found from kinetic gas theory.
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Excitation injector in an atomic chain: long-ranged transport and efficiency amplification
Auteur(s): Doyeux P., Messina R., Leggio B., Antezza M.
(Article) Publié:
-Physical Review A Atomic, Molecular, And Optical Physics [1990-2015], vol. 95 p.012138 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01448442_v1
DOI: 10.1103/PhysRevA.95.012138
WoS: 000396130200004
Exporter : BibTex | endNote
4 Citations
Résumé: We investigate the transport of energy in a linear chain of two-level quantum emitters (atoms) weakly coupled to a blackbody radiation bath. We show that simply by displacing one or more atoms from their regular-chain positions, the efficiency of the energy transport can be considerably amplified of at least one order of magnitude. In addition, in configurations providing an efficiency greater than 100%, the distance between the last two atoms of the chain can be up to 20 times larger than the one in the regular chain, thus achieving a much longer-range energy transport. By performing both a stationary and time-dependent analysis, we ascribe this effect to an elementary block of three atoms, playing the role of excitation injector from the blackbody bath to the extraction site. By considering chains with up to seven atoms, we also show that the amplification is robust and can be further enhanced up to 1400%.
Commentaires: Article 012138
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