Potsdam University Potsdam Quantum Optics Group

Universität Potsdam
Institut für Physik
Karl-Liebknecht-Str. 24/25
14476 Potsdam-Golm
Potsdam Quantum Optics Group: Home

Potsdam Quantum Optics Group: Teaching

Potsdam Quantum Optics Group: Research

Potsdam Quantum Optics Group: How to find us


H. Haakh, F. Intravaia, C. Henkel, S. Spagnolo, R. Passante, B. Power, and F. Sols
Temperature dependence of the magnetic Casimir-Polder interaction
Phys. Rev. A 80 (2009) 062905


    We analyze the magnetic dipole contribution to atom-surface dispersion forces. Unlike its electrical counterpart, it involves small transition frequencies that are comparable to thermal energy scales. A significant temperature-dependence is found near surfaces with a nonzero DC conductivity, leading to a strong suppression of the dispersion force at T > 0. We use thermal response theory for the surface material and discuss both normal metals and superconductors. The asymptotes of the free energy of interaction and of the entropy are calculated analytically over a large range of distances. Near a superconductor, the onset of dissipation at the phase transition strongly changes the interaction, including a discontinuous entropy. We discuss the similarities with the Casimir interaction beween two surfaces and suggest that precision measurements of the atom-surface interaction may settle open questions around the temperature dependence of dispersion forces in dissipative media. One way to isolate the magnetic contribution could be shifts between isotopes with different spins.

[ 0910.3133 ]

file generated: 11 Feb 2010

printer-friendly version