Accession Number:

ADA551060

Title:

Structural Anisotropy and Orientation-Induced Casimir Repulsion in Fluids

Descriptive Note:

Journal article

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF PHYSICS

Report Date:

2011-05-10

Pagination or Media Count:

12.0

Abstract:

In this work we theoretically consider the Casimir force between two periodic arrays of nanowires both in vacuum, and on a substrate separated by a fluid at separations comparable to the period. Specifically, we compute the dependence of the exact Casimir force between the arrays under both lateral translations and rotations. Although typically the force between such structures is well characterized by the proximity force approximation PFA, we find that in the present case the microstructure modulates the force in a way qualitatively inconsistent with PFA.We find instead that effective-medium theory, in which the slabs are treated as homogeneous, anisotropic dielectrics, gives a surprisingly accurate picture of the force, down to separations of half the period. This includes a situation for identical, fluid-separated slabs in which the exact force changes sign with the orientation of the wire arrays, whereas PFA predicts attraction.We discuss the possibility of detecting these effects in experiments, concluding that this effect is strong enough to make detection possible in the near future.

Subject Categories:

  • Crystallography
  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE