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arXiv · 2203.03742

Optical angular momentum in atomic transitions: a paradox

Stephen M. Barnett·Fiona C. Speirits·Mohamed Babiker
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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?

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Stephen M. Barnett, Fiona C. Speirits, Mohamed Babiker. 2022-03-07. Optical angular momentum in atomic transitions: a paradox. https://doi.org/10.1088/1751-8121%2Fac6bd1

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