RT Journal Article
SR Electronic
T1 There are many ways to spin a photon: Half-quantization of a total optical angular momentum
JF Science Advances
JO Sci Adv
FD American Association for the Advancement of Science
SP e1501748
DO 10.1126/sciadv.1501748
VO 2
IS 4
A1 Ballantine, Kyle E.
A1 Donegan, John F.
A1 Eastham, Paul R.
YR 2016
UL http://advances.sciencemag.org/content/2/4/e1501748.abstract
AB 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.