Article

# Casimir forces in the time domain: I. Theory

Physical Review A (Impact Factor: 2.81). 07/2009; 80(1). DOI: 10.1103/PhysRevA.80.012115

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**ABSTRACT:**We calculate the Casimir force on an isolated dielectric sphere in an ensemble of $N$ spheres due to multiple mutual interactions of the collection of spheres. In particular we consider dielectric spheres immersed in some other background dielectric. As an example, the Casimir force between two and three spheres at zero and finite temperature is evaluated. For a very large number of spheres, we consider a large-$N$ scaling limit of the Casimir force. Comment: 19 pages, 5 figures; references added, typos fixed, text clarified in places, last section rewritten. - [Show abstract] [Hide abstract]

**ABSTRACT:**In our previous work [Phys. Rev. Lett. 103, 103602 (2009)], we found that repulsive Casimir forces could be realized by using chiral metamaterials if the chirality is strong enough. In this work, we check four different chiral metamaterial designs (i.e., Twisted-Rosettes, Twisted-Crosswires, Four-U-SRRs, and Conjugate-Swastikas) and find that the designs of Four-U-SRRs and Conjugate-Swastikas are the most promising candidates to realize repulsive Casimir force because of their large chirality and the small ratio of structure length scale to resonance wavelength. Comment: 4 pages, 1 figure, 1 table with 16 figures, letter. submitted to Phys. Rev. B, Rapid Communication