Microscopic analysis of spin-momentum locking on a geometric phase metasurface
Abstract
We revisit spin-orbit coupling in a plasmonic Berry metasurface comprised of rotated nanoapertures, which is known to imprint a robust far-field polarization response. We present a scattering formalism that shows how that spin-momentum locking emerges from the geometry of the unit cell without requiring global rotation symmetries. We find and confirm with Mueller polarimetry measurements that spin-momentum locking is an approximate symmetry. The symmetry breakdown is ascribed to the elliptical projection of circularly polarized light into the planar surface. This breakdown is maximal when surface waves are excited, and a new set of spin-momentum locking rules is presented for this case.
Keywords
Cite
@article{arxiv.2205.10245,
title = {Microscopic analysis of spin-momentum locking on a geometric phase metasurface},
author = {Fernando Lorén and Gian L. Paravicini-Bagliani and Sudipta Saha and Jérôme Gautier and Minghao Li and Cyriaque Genet and Luis Martín-Moreno},
journal= {arXiv preprint arXiv:2205.10245},
year = {2023}
}
Comments
6 pages and 3 figures. 1 Supplemental material with 15 pages and 6 figures