ISSN:
1434-6079
Keywords:
PACS. 42.50.Xa Optical tests of quantum theory – 34.50.Dy Interactions of atoms and molecules with surfaces; photon and electron emission; neutralization of ions – 42.50.Ct Quantum description of interaction of light and matter; related experiments – 32.70.Jz Line shapes, widths, and shifts – 78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract: We present a detailed experimental study of the evaluation of the van der Waals (vW) atom-surface interaction for high-lying excited states of alkali-metal atoms (Cs and Rb), notably when they couple resonantly with a surface-polariton mode of the neighbouring dielectric surface. This report extends our initial observation [Phys. Rev. Lett. 83, 5467 (1999)] of a vW repulsion between Cs(6D3/2) and a sapphire surface. The experiment is based upon FM selective reflection spectroscopy, on a transition reaching a high-lying state from a resonance level, that has been thermally pumped by an initial one-photon step. Along with a strong vW repulsion fitted with a blue lineshift, -160±25 kHz μm3 for Cs(6D3/2) in front of a sapphire surface (with a perpendicular c-axis), we demonstrate a weaker vW repulsion (-32±5 kHz μm3) for Cs(6D3/2) in front of a YAG surface, as due to a similar resonant coupling at 12 μm between a virtual atomic emission (6D3/2-7P1/2) and the surface polariton modes. A resonant behaviour of Rb(6D5/2) in front of a sapphire surface exists also because of analogous decay channels in the 12 μm range. Finally, one demonstrates that fused silica, nonresonant for a virtual transition in the 12 μm range and hence weakly attracting for Cs(6D3/2), exhibits a resonant behaviour for Cs(9S1/2) as due to its surface polariton resonance in the 8-9 μm range. The limiting factors that affect both the accuracy of the theoretical prediction, and that of the fitting method applied to the experimental data, are discussed in the conclusion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1140/epjd/e2003-00098-4
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