There are many ways to spin a photon : half-quantization of a total optical angular momentum
MetadataShow full item record
The angular momentum of light plays an important role in many areas, from optical trapping to quantum information. In the usual three-dimensional setting, the angular momentum quantum numbers of the photon are integers, in units of the Planck constant ħ. We show that, in reduced dimensions, photons can have a half-integer total angular momentum. We identify a new form of total angular momentum, carried by beams of light, comprising an unequal mixture of spin and orbital contributions. We demonstrate the half-integer quantization of this total angular momentum using noise measurements. We conclude that for light, as is known for electrons, reduced dimensionality allows new forms of quantization.
Ballantine , K E , Donegan , J F & Eastham , P R 2016 , ' There are many ways to spin a photon : half-quantization of a total optical angular momentum ' Science Advances , vol 2 , no. 4 , e1501748 . DOI: 10.1126/sciadv.1501748
Copyright © 2016, The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
This work was supported by the Higher Education Authority of Ireland under PRTLI (Programme for Research in Third-Level Institutions) funding cycle 5 and by Science Foundation Ireland (09/SIRG/I1592, 12/RC/2278).
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.