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Théorie du rayonnement matière et phénomènes quantiques
(14) Production(s) de l'année 2018
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Latest Advances on Modal Methods in Computational Electromagnetics: Applications in Nanophotonics and Plasmonics
Auteur(s): Edee Kofi, Ben Rhouma Maha, Antezza M., Guizal B.
Conference: PIERS : Progress In Electromagnetics Research Symposium (Toyama, JP, 2018-08-01)
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Résumé: Metasurfaces are planar metamaterials that consist of a single or a few stack of subwavelength thickness metal-dielectric layers. They could be periodically structured or not with subwavelength scale patterns according to the transverse directions. The strong interac- tion between an electromagnetic field components and these surfaces, exhibits some properties that could not be found in nature. These artificial properties strongly depend on the shape and arrangement of the elementary patterns and they are often linked to a plasmon resonance phe- nomenon. Metasurfaces working in the visible range generally consist in periodical arrangments of plasmonic resonators. These resonators are inherently muti-scale, as their responses relie on the excitation of resonances in very small gaps, like in the case of gap-plasmon resonators [1] or for bow-tire antennas. The simulation of their electromagnetic response can be very challeng- ing and may be successfully treated thanks to a modal method holding the complexity of the patterns shape. Here we present a polynomial modal method [2–5] that is particularly suited for the simulation of metallic structures. Advanced coordinates transformation such as matched coordinates and tilted coordinates are included in order to hold efficiently the complexity of the geometry without any approximation. Such a tool even offers the possibility to control the way the resonators are periodically arranged.
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Near-field heat transfer between graphene/hBN multilayers
Auteur(s): Guizal B., Zhao Bo, Zhang Z., Fan Shanhui, Antezza M.
Conférence invité: PIERS: Progress In Electromagnetics Research Symposium (Toyama, JP, 2018-08-01)
Ref HAL: hal-01863580_v1
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Résumé: We study the radiative heat transfer between multilayer structures made by a periodic repetition of a graphene sheet and a hexagonal boron nitride (hBN) slab. Surface plasmons in a monolayer graphene can couple with hyperbolic phonon polaritons in a single hBN film to form hybrid polaritons that can assist photon tunneling. For periodic multilayer graphene/hBN structures, the stacked metallic/dielectric array can give rise to a further effective hyperbolic behavior, in addition to the intrinsic natural hyperbolic behavior of hBN. The effective hyperbolicity can en- able more hyperbolic polaritons that enhance the photon tunneling and hence the near-field heat transfer. However, the hybrid polaritons on the surface, i.e., surface plasmon-phonon polaritons, dominate the near-field heat transfer between multilayer structures when the topmost layer is graphene. The effective hyperbolic regions can be well predicted by the effective medium theory (EMT), thought EMT fails to capture the hybrid surface polaritons and results in a heat trans- fer rate much lower compared to the exact calculation. The chemical potential of the graphene sheets can be tuned through electrical gating and results in an additional modulation of the heat transfer. We found that the near-field heat transfer between multilayer structures does not increase monotonously with the number of layers in the stack, which provides a way to control the heat transfer rate by the number of graphene layers in the multilayer structure. The results may benefit the applications of near-field energy harvesting and radiative cooling based on hybrid polaritons in two-dimensional materials.
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Spontaneous lateral atomic recoil force close to a photonic topological material
Auteur(s): Hassani Gangaraj S. Ali, Hanson George W., Antezza M., Silveirinha Mario
(Article) Publié:
Physical Review B, vol. 97 p.201108(R) (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01792421_v1
DOI: 10.1103/PhysRevB.97.201108
WoS: 000432966100001
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26 Citations
Résumé: We investigate the quantum recoil force acting on an excited atom close to the surface of a nonreciprocal photonic topological insulator (PTI). The main atomic emission channel is the unidirectional surface plasmon propagating at the PTI-vacuum interface, and we show that it enables a spontaneous lateral recoil force that scales at short distances as 1/d^4, where d is the atom-PTI separation. Remarkably, the sign of the recoil force is polarization and orientation independent, and it occurs in a translation-invariant homogeneous system in thermal equilibrium. Surprisingly, the recoil force persists for very small values of the gyration pseudovector, which, for a biased plasma, corresponds to very low cyclotron frequencies. The ultrastrong recoil force is rooted in the quasihyperbolic dispersion of the surface plasmons. We consider both an initially excited atom and a continuous pump scenario, the latter giving rise to a steady lateral force whose direction can be changed at will by simply varying the orientation of the biasing magnetic field. Our predictions may be tested in experiments with cold Rydberg atoms and superconducting qubits.
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Matched coordinates in the framework of polynomial modal methods for complex metasurface modeling
Auteur(s): Edee Kofi, Plumey Jean-Pierre, Moreau A., Guizal B.
(Article) Publié:
Journal Of The Optical Society Of America A, vol. 35 p.608-615 (2018)
Ref HAL: hal-01742077_v1
DOI: 10.1364/JOSAA.35.000608
WoS: 000428931500056
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4 Citations
Résumé: The polynomial modal method (PMM) is one of the most powerful methods for modeling diffraction from lamellar gratings. In the present work, we show that applying it to the so-called matched coordinates leads to important improvement of convergence for crossed lamellar gratings with patterns that are not parallel to the coordinates’ axes. After giving the new formulation of the PMM under matched coordinates in the general framework of biperiodic structures, we provide numerical examples to demonstrate the effectiveness of the proposed approach.
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A self-contained quantum harmonic engine
Auteur(s): Reid Brendan, Pigeon Simon, Antezza M., De Chiara G.
(Article) Publié:
Europhysics Letters (Epl), vol. 120 p.60006 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01726096_v1
DOI: 10.1209/0295-5075/120/60006
WoS: 000426262900001
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13 Citations
Résumé: We propose a system made of three quantum harmonic oscillators as a compact quantum engine for producing mechanical work. The three oscillators play respectively the role of the hot bath, the working medium and the cold bath. The working medium performs an Otto cycle during which its frequency is changed and it is sequentially coupled to each of the two other oscillators. As the two environments are finite, the lifetime of the machine is finite and after a number of cycles it stops working and needs to be reset. Remarkably, we show that thismachine can extract more than 90% of the available energy during 70 cycles. Differently from usually investigated infinite-reservoir configurations, this machine allows the protection of induced quantum correlations and we analyse the entanglement and quantum discord generated during the strokes. Interestingly, we show that high work generation is always accompanied by large quantum correlations. Our predictions can be useful for energy management at the nanoscale, and can be relevant for experiments with trapped ions and experiments with light in integrated optical circuits.
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Fluctuation-induced forces on an atom near a photonic topological material
Auteur(s): Silveirinha Mario, Hassani Gangaraj S. Ali, Hanson George W., Antezza M.
(Article) Publié:
-Physical Review A Atomic, Molecular, And Optical Physics [1990-2015], vol. 97 p.022509 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01714025_v1
DOI: 10.1103/PhysRevA.97.022509
WoS: 000425489100009
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22 Citations
Résumé: We theoretically study the Casimir-Polder force on an atom in an arbitrary initial state in a rather general electromagnetic environment wherein the materials may have a nonreciprocal bianisotropic dispersive response. It is shown that under the Markov approximation the force has resonant and nonresonant contributions. We obtain explicit expressions for the optical force both in terms of the system Green function and of the electromagnetic modes. We apply the theory to the particular case wherein a two-level system interacts with a topological gyrotropic material, showing that the nonreciprocity enables exotic light-matter interactions and the opportunity to sculpt and tune the Casimir-Polder forces on the nanoscale. With a quasistatic approximation, we obtain a simple analytical expression for the optical force and unveil the crucial role of surface plasmons in fluctuation-induced forces. Finally, we derive the Green function for a gyrotropic material half-space in terms of a Sommerfeld integral.
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Ballistic near-field heat transport in dense many-body systems
Auteur(s): Latella Ivan, Biehs Svend-Age, Messina R., Rodriguez Alejandro W., Ben-Abdallah Philippe
(Article) Publié:
Physical Review B, vol. 97 p.35423 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01690614_v1
DOI: 10.1103/PhysRevB.97.035423
WoS: 000423118900005
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14 Citations
Résumé: Radiative heat transport mediated by near-field interactions is known to be superdiffusive in dilute, many-body systems. Here we use a generalized Landauer theory of radiative heat transfer in many-body planar systems to demonstrate a nonmonotonic transition from superdiffusive to ballistic transport in dense systems. We show that such a transition is associated to a change of the polarization of dominant modes. Our findings are complemented by a quantitative study of the relaxation dynamics of the system in the different regimes of heat transport. This result could have important consequences on thermal management at nanoscale of many-body systems.
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