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(89) Production(s) de GUIZAL B.
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Semi-analytical model for the analysis of a magnetically biased 1D subwavelength graphene-strip-grating
Auteur(s): Ben Rhouma Maha, Guizal B., Bonnet Pierre, Paladian Francoise, Edee Kofi
(Article) Publié:
Osa Continuum, vol. 1 p.1144 (2022)
Texte intégral en Openaccess :
Ref HAL: hal-03670768_v1
DOI: 10.1364/OPTCON.446632
Exporter : BibTex | endNote
Résumé: We propose a simple semi analytical model that allows to compute the transmittance and reflectance of a one dimensional subwavelength graphene strip grating under an external static magnetic field. In this model graphene is treated as an anisotropic layer with atomic thickness and a frequency dependent complex permittivity tensor. The model is based on an effective medium approach (EMA) and a rigorous phase correction. The scattering matrix approach is also used to take into account the different resonant phenomena occurring in the structure. The approach is validated against the Polynomial Modal Method (PMM) through numerical examples.
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Efficient computation of EM scattering from a dielectric cylinder covered with graphene strips
Auteur(s): Guizal B., Jeyar Y., Antezza M.
Conférence invité: The 14th International Conference “Micro- and Nanoelectronics – 2021” (ICMNE-2021) (Zvenigorod, Moscow Region, RU, 2021-10-04)
Ref HAL: hal-03391523_v1
Exporter : BibTex | endNote
Résumé: We present a numerical approach for the solution of EM scattering from a dielectric cylinder partially covered with graphene. It is based on a classical Fourier-Bessel expansion of the fields inside and outside the cylinder to which we apply the ad-hoc boundary conditions in the presence of graphene. Due to the singular nature of the electric field at the ends of the graphene sheet, we introduce auxiliary boundary conditions to better take this reality into account. The result is a very simple and very efficient method allowing the study of diffraction from such structures.
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Efficient computation of EM scattering from a dielectric cylinder covered with graphene strips for heat transfer
Auteur(s): Jeyar Y., Antezza M., Guizal B.
Conference: European Optical Society : Annual Meeting 2021 (EOSAM2021) (Rome, IT, 2021-09-13)
Ref HAL: hal-03357063_v1
Exporter : BibTex | endNote
Résumé: We present a numerical approach for the solution of EM scattering from a dielectric cylinder partially covered with graphene. It is based on a clas- sical Fourier-Bessel expansion of the fields inside and outside the cylinder to which we apply the ad-hoc boundary conditions in the presence of graphene. Due to the singular nature of the electric field at the ends of the graphene sheet, we introduce auxiliary boundary conditions to better take this reality into ac- count. The result is a very simple and very efficient method allowing the study of diffraction from such structures. Our ultimate goal is to apply this approach to radiative heat transfer between graphene coated cylinders and planes.
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Strong geometry dependence of the Casimir force between interpenetrated rectangular gratings
Auteur(s): Wang Mingkang, Tang Lu, Messina C. Y. Ng Riccardo, Guizal B., Crosse J. A., Antezza M., Chan Che Ting, Chan Ho Bun
(Article) Publié:
Nature Communications, vol. 12 p.600 (2021)
Texte intégral en Openaccess :
Ref HAL: hal-03122200_v1
DOI: 10.1038/s41467-021-20891-4
Exporter : BibTex | endNote
Résumé: Quantum fluctuations give rise to Casimir forces between two parallel conducting plates, the magnitude of which increases monotonically as the separation decreases. By introducing nanoscale gratings to the surfaces, recent advances have opened opportunities for controlling the Casimir force in complex geometries. Here, we measure the Casimir force between two rectangular silicon gratings. Using an on-chip detection platform, we achieve accurate alignment between the two gratings so that they interpenetrate as the separation is reduced. Just before interpenetration occurs, the measured Casimir force is found to have a geometry dependence that is much stronger than previous experiments, with deviations from the proximity force approximation reaching a factor of ~500. After the gratings interpenetrate each other, the Casimir force becomes non-zero and independent of displacement. This work shows that the presence of gratings can strongly modify the Casimir force to control the interaction between nanomechanical components.
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Many-body effective thermal conductivity in phase-change nanoparticle chains due to near-field radiative heat transfer
Auteur(s): Luo M., Zhao Junming, Liu Linhua, Guizal B., Antezza M.
(Article) Publié:
International Journal Of Heat And Mass Transfer, vol. 166 p.120793 (2020)
Texte intégral en Openaccess :
Ref HAL: hal-03059594_v1
DOI: 10.1016/j.ijheatmasstransfer.2020.120793
Exporter : BibTex | endNote
Résumé: In dense systems composed of numerous nanoparticles, direct simulations of near-field radiative heat transfer (NFRHT) require considerable computational resources. NFRHT for the simple one-dimensional nanoparticle chains embedded in a non-absorbing host medium is investigated from the point of view of the continuum by means of an approach combining the many-body radiative heat transfer theory and the Fourier law. Effects of the phase change of the insulator-metal transition material (), the complex many-body interaction (MBI) and the host medium relative permittivity on the characteristic effective thermal conductivity (ETC) are analyzed. The ETC for nanoparticle chains below the transition temperature can be as high as 50 times of that above the transition temperature due to the phase change effect. The strong coupling in the insulator-phase nanoparticle chain accounts for its high ETC as compared to the low ETC for the chain at the metallic phase, where there is a mismatch between the characteristic thermal frequency and resonance frequency. The strong MBI is in favor of the ETC. For SiC nanoparticle chains, the MBI even can double the ETC as compared to those without considering the MBI effect. For the dense chains, a strong MBI enhances the ETC due to the strong inter-particles couplings. When the chains go more and more dilute, the MBI can be neglected safely due to negligible couplings. The host medium relative permittivity significantly affects the inter-particles couplings, which accounts for the permittivity-dependent ETC for the nanoparticle chains.
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Giant Casimir Torque between Rotated Gratings and the θ = 0 Anomaly
Auteur(s): Antezza M., Chan Ho Bun, Guizal B., Marachevskii V., Messina R., Wang Mingkang
(Article) Publié:
Physical Review Letters, vol. 124 p.013903 (2020)
Texte intégral en Openaccess :
Ref HAL: hal-02431447_v1
DOI: 10.1103/PhysRevLett.124.013903
WoS: 000505997600005
Exporter : BibTex | endNote
2 Citations
Résumé: We study the Casimir torque between two metallic one-dimensional gratings rotated by an angle θ with respect to each other. We find that, for infinitely extended gratings, the Casimir energy is anomalously discontinuous at θ 1⁄4 0, due to a critical zero-order geometric transition between a 2D- and a 1D-periodic system. This transition is a peculiarity of the grating geometry and does not exist for intrinsically anisotropic materials. As a remarkable practical consequence, for finite-size gratings, the torque per area can reach extremely large values, increasing without bounds with the size of the system. We show that for finite gratings with only ten period repetitions, the maximum torque is already 60 times larger than the one predicted in the case of infinite gratings. These findings pave the way to the design of a contactless quantum vacuum torsional spring, with possible relevance to micro- and nanomechanical devices.
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Long-range Heat and Energy Transfer through Hyperbolic Materials
Auteur(s): Biehs Svend-Age, Messina R., Guizal B., Antezza M., Ben-Abdallah Philippe, Deshmukh R., Galfsky T., Menon V, Agarwal G. S.
Conférence invité: PIERS 2019 (Rome, IT, 2019-06-20)
Ref HAL: hal-02190887_v1
Exporter : BibTex | endNote
Résumé: Heat flux exchanged between two hot bodies at subwavelength separation distances can exceed the limitpredicted by the blackbody theory. However, this super-Planckian transfer is restricted to these separationdistances. Here we demonstrate the possible existence of a super-Planckian transfer at arbitrary large separationdistances if the interacting bodies are connected in the near field with weakly dissipating hyperbolic waveguides.This result opens the way to long-distance transport of near-field thermal energy.
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