Accueil >
Production scientifique
Optique des états collectifs et du spin
(25) Production(s) de l'année 2017
|
|
ThermalandElectrostaticManipulationoftheCasimirForceinGrapheneMultilayers
Auteur(s): Guizal B., Abbas C., Antezza M.
Conférence invité: Global summit on Laser Optics & Photonics (Valencia, ES, 2017-06-19)
Ref HAL: hal-01548335_v1
Exporter : BibTex | endNote
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 for isolated 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.
|
|
|
Nuclear spin relaxation in n-GaAs: From insulating to metallic regime
Auteur(s): Vladimirova M., Cronenberger S., Scalbert D., Kotur M., Dzhioev R. I., Ryzhov I. I., Kozlov G. G., Zapasskii V. S., Lemaitre A., Kavokin K. V.
(Article) Publié:
Physical Review B, vol. 95 p.125312 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01523113_v1
DOI: 10.1103/PhysRevB.95.125312
WoS: WOS:000399218900003
Exporter : BibTex | endNote
8 Citations
Résumé: Nuclear spin relaxation is studied in n-GaAs thick layers and microcavity samples with different electron densities.We reveal that both in metallic samples where electrons are free and mobile, and in insulating samples where electrons are localized, nuclear spin relaxation is strongly enhanced at low magnetic fields. The origin of this effect could reside in the quadrupole interaction between nuclei and fluctuating electron charges, that has been proposed to govern nuclear spin dynamics at low magnetic fields in the insulating samples. The characteristic values of these magnetic fields are given by dipole-dipole interaction between nuclei in bulk samples, and are greatly enhanced in microcavities, presumably due to additional strain, inherent to microstructures and nanostructures.
|
|
|
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.
|
|
|
Dynamic Nuclear Polarization and Nuclear Fields
Auteur(s): Vladimirova M., Kalevich Vladimir, Merkulov Igor, Kavokin Kirill
Chapître d'ouvrage: Spin Physics In Semiconductors, vol. p.387-430 (2017)
|