Dynamics of thermal Casimir-Polder forces on polar molecules

作者：Ellingsen Simen Adnoy^*; Buhmann Stefan Yoshi; Scheel Stefan

来源：Physical Review A, 2009, 79(5): 052903.

DOI：10.1103/PhysRevA.79.052903

• Casimir effect
• ground states
• laser cooling
• molecule-photon collisions
• radiation pressure
• rotational-vibrational states

We study the influence of thermal Casimir-Polder forces on the near-surface trapping of cold polar molecules, with emphasis on LiH and YbF near a Au surface at room temperature. We show that even for a molecule initially prepared in its electronic and rovibrational ground state, the Casimir-Polder force oscillates with the molecule-wall separation. The nonresonant force and the evanescent part of the resonant force almost exactly cancel at high temperature which results in a saturation of the (attractive) force in this limit. This implies that the Casimir-Polder force on a fully thermalized molecule can differ dramatically from that obtained using a naive perturbative expansion of the Lifshitz formula based on the molecular ground-state polarizability. A dynamical calculation reveals how the spatial oscillations die out on a typical time scale of several seconds as thermalization of the molecule with its environment sets in.

• 出版日期2009-5