Casimir-Lifshitz Torque Enhancement by Retardation and Intervening Dielectrics

David A. T. Somers and Jeremy N. Munday

Phys. Rev. Lett. 119, 183001 – Published 3 November 2017

Abstract

We investigate two effects that lead to a surprising increase in the calculated Casimir-Lifshitz torque between anisotropic, planar, semi-infinite slabs. Retardation effects, which account for the finite speed of light, are generally assumed to decrease the strength of Casimir-Lifshitz interactions. However, the nonretarded approximation underestimates the Casimir-Lifshitz torque at small separations by as much as an order of magnitude. Also, Casimir-Lifshitz forces are typically weakened with the insertion of an intervening dielectric. However, a dielectric medium can increase the short-range Casimir-Lifshitz torque by as much as a factor of 2. The combined effects of retardation and an intervening dielectric dramatically enhance the Casimir-Lifshitz torque in the experimentally accessible regime and should not be neglected in calculation or experimental design.

Received 19 July 2017

DOI:https://doi.org/10.1103/PhysRevLett.119.183001

Physics Subject Headings (PhySH)

Casimir effect Casimir effect & related phenomena Van der Waals interaction

Condensed Matter, Materials & Applied PhysicsAtomic, Molecular & OpticalInterdisciplinary PhysicsNonlinear DynamicsGeneral PhysicsPolymers & Soft Matter

Authors & Affiliations

David A. T. Somers^1,2 and Jeremy N. Munday^2,3,*

¹Department of Physics, University of Maryland, College Park, Maryland 20740, USA
²Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20740, USA
³Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20740, USA