Nonmonotonic effects of parallel sidewalls on Casimir forces between cylinders

Sahand Jamal Rahi 1, Alejandro W. Rodriguez 1, Thorsten Emig 2, 3, Robert L. Jaffe 4, Steven G. Johnson 5, Mehran Kardar 1

Physical Review A: Atomic, Molecular and Optical Physics 77 (2008) 030101

We analyze the Casimir force between two parallel infinite metal cylinders, with nearby metal plates (sidewalls), using complementary methods for mutual confirmation. The attractive force between cylinders is shown to have a nonmonotonic dependence on the separation to the plates. This intrinsically multi-body phenomenon, which occurs with either one or two sidewalls (generalizing an earlier result for squares between two sidewalls), does not follow from any simple two-body force description. We can, however, explain the nonmonotonicity by considering the screening (enhancement) of the interactions by the fluctuating charges (currents) on the two cylinders, and their images on the nearby plate(s). Furthermore, we show that this effect also implies a nonmonotonic dependence of the cylinder-plate force on the cylinder-cylinder separation.

  • 1. Department of Physics,
    Massachusetts Institute of Technology
  • 2. Institut für Theoretische Physik,,
    Universität zu Köln
  • 3. Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS),
    CNRS : UMR8626 – Université Paris XI - Paris Sud
  • 4. Center for Theoretical Physics and Laboratory for Nuclear Science,
    Massachusetts Institute of Technology
  • 5. Department of Mathematics,
    Massachusetts Institute of Technology