Photon emission from translational energy in atomic collisions: A dynamic Casimir-Polder effect
2005 (English)In: PHYSICAL REVIEW A, ISSN 1050-2947, Vol. A 71, no 062106, 1-5 p.Article in journal (Refereed) Published
It is demonstrated, using a Liouville formalism, that the relative motion of two atoms can result in the emission of photons and conversely that photons can be absorbed to excite the relative translational motion. The mechanism responsible for the energy transfer between the radiation field and the translational motion of the atoms is a dynamic version of the long-range Casimir-Polder interaction between two fixed atoms. The phenomenon is analogous to the dynamic Casimir effect discussed for moving macro- (or meso)scopic objects and we term it the dynamic Casimir-Polder effect. The absorption or emission is a two-photon process and we find that the transition probability is proportional to the spectral density of a correlation function involving the relative translational motion of two atoms. An energy transfer only occurs for photons with energies smaller than or of the same magnitude as the thermal energy. The effect provides a microscopic mechanism for establishing thermal equilibrium between the radiation field and a gas. A sufficiently large volume of gas would be perceived as a black-body radiator. Applications of the dynamic Casimir-Polder effect might be found in the microscopic description of the cosmic low-temperature black-body radiation.
Place, publisher, year, edition, pages
2005. Vol. A 71, no 062106, 1-5 p.
SONOLUMINESCENCE, LIGHT, TEMPERATURE, RELAXATION, EQUATION, VACUUM, CAVITY
IdentifiersURN: urn:nbn:se:umu:diva-13243DOI: doi:10.1103/PhysRevA.71.062106OAI: oai:DiVA.org:umu-13243DiVA: diva2:152914
Art. No. 062106 JUN 20052008-03-282008-03-282011-01-12Bibliographically approved