engleski

Medium-modified Casimir Forces

We compare vacuum forces on a slab and on an atom in a magnetodielectric planar cavity as obtained using a traditional approach [1] and recently suggested the Lorentz-force approach [2] to the Casimir effect. We demonstrate that the force on a slab (an atom) embedded in the cavity medium differs substantially from the force on a layer (an atom) of the cavity medium. We also derive general expressions for the force on a magnetodielectric slab (an electrically and magnetically polarizable atom) in both cases. The force on an embedded object is of the familiar type, however, more strongly modified by the cavity medium than usually considered. The forces on a layer and an atom of the cavity medium are very recently predicted medium-assisted forces [3], with very unusual properties. At small distances from a mirror, they are described by the power laws whose exponents are decreased by 2 in comparison with the exponents in the corresponding power laws of embedded objects. At large distances, however, they obey the standard (Casimir and Casimir-Polder, respectively) power laws. Moreover, the signs of these forces are insensitive to the electric/magnetic properties of the slab and the atom. [1] M. S. Tomaš, Phys. Rev. A 66, 052103 (2002). [2] C. Raabe and D.-G. Welsch, Phys. Rev. A 71, 013814 (2005). [3] M. S. Tomaš, Phys. Rev. A 71, 060101(R) (2005).

Vacuum forces; Casimir effect; planar cavity

Prihvaćen (recenziran) rad objavljen je u specijalnom broju Journal of Physics A: Mathematical and general 39 (2006) 6785.