- Letter
Casimir effect in twisted photonic gratings with in-plane chirality
Phys. Rev. A 113, L031502 – Published 23 March, 2026
DOI: https://doi.org/10.1103/6z4l-xb93
Abstract
We investigate the Casimir effect in a system of two twisted photonic gratings made of uniaxially anisotropic materials. Two distinct configurations are explored: a stack of symmetric gratings and a stack of in-plane chiral grating, with the latter realized by choosing a specific orientation of the anisotropy axis relative to stripes. We apply the reflection-matrix-based Casimir-Lifshitz formalism to explore how twist angle, material anisotropy, and the separation between gratings influence Casimir energy, force, and torque. Our calculations reveal that the equilibrium orientation of the gratings is governed by the anisotropy rotation angles, leading to a chiral configuration where the anisotropy axes of the upper and lower gratings are mutually parallel. These findings demonstrate that material anisotropy provides a powerful mechanism for controlling rotational alignment forces in nanophotonic systems.
