# Negative Casimir entropies in nanoparticle interactions.

@article{Milton2015NegativeCE, title={Negative Casimir entropies in nanoparticle interactions.}, author={Kimball A. Milton and Romain Gu{\'e}rout and Gert-Ludwig Ingold and Astrid Lambrecht and Serge Reynaud}, journal={Journal of physics. Condensed matter : an Institute of Physics journal}, year={2015}, volume={27 21}, pages={ 214003 } }

Negative entropy has been known in Casimir systems for some time. For example, it can occur between parallel metallic plates modeled by a realistic Drude permittivity. Less well known is that negative entropy can occur purely geometrically, say between a perfectly conducting sphere and a conducting plate. The latter effect is most pronounced in the dipole approximation, which is reliable when the size of the sphere is small compared to the separation between the sphere and the plate. Therefore…

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