English

Optical angular momentum in atomic transitions: a paradox

Optics 2022-06-01 v1 Quantum Physics

Abstract

Stated simply the paradox is as follows: it is clear that the orbital angular momentum of a light beam in its direction of propagation is an intrinsic quantity, and therefore has the same value everywhere in the beam. How then can a Gaussian beam, with precisely zero orbital angular momentum, drive a (single-photon) quadrupole transition which requires the transfer of angular momentum 2\hbar to an absorbing atom?

Keywords

Cite

@article{arxiv.2203.03742,
  title  = {Optical angular momentum in atomic transitions: a paradox},
  author = {Stephen M. Barnett and Fiona C. Speirits and Mohamed Babiker},
  journal= {arXiv preprint arXiv:2203.03742},
  year   = {2022}
}

Comments

Submitted to J.Phys.A. Special Issue "Claritons and the Asymptotics of Ideas: the Physics of Michael Berry"

R2 v1 2026-06-24T10:05:19.785Z