@article {Ballantinee1501748,
author = {Ballantine, Kyle E. and Donegan, John F. and Eastham, Paul R.},
title = {There are many ways to spin a photon: Half-quantization of a total optical angular momentum},
volume = {2},
number = {4},
year = {2016},
doi = {10.1126/sciadv.1501748},
publisher = {American Association for the Advancement of Science},
abstract = {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 h. 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.},
URL = {http://advances.sciencemag.org/content/2/4/e1501748},
eprint = {http://advances.sciencemag.org/content/2/4/e1501748.full.pdf},
journal = {Science Advances}
}