Temperature dependence of the dielectric permittivity of CaF2, BaF2 and Al2O3: application to the prediction of a temperature dependent van der Waals surface interaction exerted onto a neighbouring Cs (8P{3/2}) atom

Thierry Passerat de Silans (1) , Isabelle Maurin (1) , Pedro Chaves de Souza Segundo (1) , Solomon Saltiel (1) , Marie-Pascale Gorza (1) , Martial Ducloy (1) , Daniel Bloch (1) , Domingo de Sousa Meneses (2) , Patrick Echegut (2)

1 LPL - Laboratoire de Physique des Lasers
2 CEMHTI - Conditions Extrêmes et Matériaux : Haute Température et Irradiation

The temperature behaviour in the range 22°C to 500 °C of the dielectric permittivity in the infrared range is investigated for CaF2, BaF2 and Al2O3 through reflectivity measurements. The dielectric permittivity is retrieved by fitting reflectivity spectra with a model taking into account multiphonon contributions. The results extrapolated from the measurements are applied to predict a temperature-dependent atom-surface van der Waals interaction. We specifically consider as the atom of interest Cs (8P3/2), the most relevant virtual couplings of which, fall in the range of thermal radiation and are located in the vicinity of the reststrahlen band of fluoride materials.

Mots clés: infrared spectroscopy; dielectric permittivity; temperature dependence; calcium fluoride; barium fluoride; sapphire

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Optique [physics.optics]; Physique Atomique [physics.atom-ph]

Thierry Passerat de Silans, Isabelle Maurin, Pedro Chaves de Souza Segundo, Solomon Saltiel, Marie-Pascale Gorza, et al.. Temperature dependence of the dielectric permittivity of CaF2, BaF2 and Al2O3: application to the prediction of a temperature dependent van der Waals surface interaction exerted onto a neighbouring Cs (8P{3/2}) atom. Journal of Physics: Condensed Matter, 2009, 21, pp.255902. ⟨10.1088/0953-8984/21/25/255902⟩. ⟨hal-00389083⟩