Abstract

The onset of retardation effects in atom-wall interactions is studied. It is shown that the transition range from the 1/z3 short-range (van der Waals) interaction to the 1/z4 long-range (Casimir) retarded interaction critically depends on the atomic properties and on the dielectric function of the material. For simple non-alkali-metal atoms (e.g., ground-state hydrogen and ground-state helium) interacting with typical dielectric materials such as intrinsic silicon, the transition to the retarded regime is shown to proceed at a distance of about 10 nm (200 Bohr radii). This is much shorter than typical characteristic absorption wavelengths of solids. Larger transition regimes are obtained for atoms with a large static polarizability such as metastable helium. We present a simple estimate for the critical distance, zcr=137α(0)/Z atomic units, where α(0) is the static polarizability (expressed in atomic units) and Z is the number of electrons of the atom.

Department(s)

Physics

Comments

National Science Foundation, Grant DMR–2149082

International Standard Serial Number (ISSN)

2469-9934; 2469-9926

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2024 American Physical Society, All rights reserved.

Publication Date

01 Feb 2024

Included in

Physics Commons

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