English

The electromagnetic symmetry sphere: a framework for energy, momentum, spin and other electromagnetic quantities

Optics 2024-07-10 v2

Abstract

Electromagnetic quantities such as energy density, momentum, spin, and helicity bring meaning and intuition to electromagnetism and possess intricate interrelations, particularly prominent in complex non-paraxial near-fields. These quantities are conventionally expressed using electric and magnetic field vectors, yet the electric-magnetic basis is one among other often overlooked alternatives, including parallel-antiparallel and right-left-handed helicity bases, related to the parity and duality symmetries of electromagnetism. Projecting time-harmonic electromagnetic fields into a variety of bases allows re-interpreting established quantities and reveals underlying mathematical structures: a Bloch sphere which describes asymmetries in electromagnetic energy, a systematic path to unify and uncover relations between electromagnetic quantities, and the unlocking of symmetry-driven equations in light-matter interaction.

Keywords

Cite

@article{arxiv.2405.15718,
  title  = {The electromagnetic symmetry sphere: a framework for energy, momentum, spin and other electromagnetic quantities},
  author = {Sebastian Golat and Alex J. Vernon and Francisco J. Rodríguez-Fortuño},
  journal= {arXiv preprint arXiv:2405.15718},
  year   = {2024}
}

Comments

6 pages, 2 figures, 3 tables