Do waves carrying orbital angular momentum possess azimuthal linear momentum?

Speirits, Fiona C. and Barnett, Stephen M. (2013) Do waves carrying orbital angular momentum possess azimuthal linear momentum? Physical Review Letters, 111 (10). 103602. ISSN 0031-9007

[thumbnail of SpeiritsBarnett-PRL20130-orbital-angular-momentum]
Preview
PDF (SpeiritsBarnett-PRL20130-orbital-angular-momentum)
SpeiritsBarnett_PRL20130_orbital_angular_momentum.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (82kB)| Preview

    Abstract

    All beams are a superposition of plane waves, which carry linear momentum in the direction of propagation with no net azimuthal component. However, plane waves incident on a hologram can produce a vortex beam carrying orbital angular momentum that seems to require an azimuthal linear momentum, which presents a paradox. We resolve this by showing that the azimuthal momentum is not a true linear momentum but the azimuthal momentum density is a true component of the linear momentum density.