Casimir-Lifshitz force out of thermal equilibrium between dielectric gratings

TL;DR

This paper investigates the Casimir-Lifshitz force between two dielectric gratings out of thermal equilibrium, revealing tunable attractive and repulsive regimes influenced by temperature and geometry, with potential experimental implications.

Contribution

It introduces a detailed calculation of non-equilibrium Casimir-Lifshitz forces between dielectric gratings using scattering operators and explores how temperature and geometry control the force's behavior.

Findings

Force can be significantly reduced at large temperature ranges.

Repulsive Casimir-Lifshitz pressure can be achieved and tuned.

Transition distance between attraction and repulsion is decreased compared to slabs.

Abstract

We calculate the Casimir-Lifshitz pressure in a system consisting of two different 1D dielectric lamellar gratings having two different temperatures and immersed in an environment having a third temperature. The calculation of the pressure is based on the knowledge of the scattering operators, deduced using the Fourier Modal Method. The behavior of the pressure is characterized in detail as a function of the three temperatures of the system as well as the geometrical parameters of the two gratings. We show that the interplay between non-equilibrium effects and geometrical periodicity offers a rich scenario for the manipulation of the force. In particular, we find regimes where the force can be strongly reduced for large ranges of temperatures. Moreover, a repulsive pressure can be obtained, whose features can be tuned by controlling the degrees of freedom of the system. Remarkably, the transition distance between attraction and repulsion can be decreased with respect to the case of two slabs, implying an experimental interest for the observation of repulsion.