A new discovery made by two Irish Physicists has changed our fundamental understanding of light, with implications effecting quantum computing and fiber-optic communications. The discovery was made by Paul Eastham and John Donegan from Trinity College Dublin’s School of Physics. In the 1830s physicists concluded that photons were limited to integer values of angular momentum. It was believed that angular momentum had to be multiples of Planks constant, ħ.
But a recent breakthrough made by Paul Eastham and John Donegan showed that this is not always the case. Photons in fact can have half-integer values of angular momentum when they are confined to fewer than three dimensions.
To make this discovery the team turned light into a hollow cylinder by passing it through a crystal, and measured its angular momentum when the light passed and bypassed the crystal. They found that when it passed through the crystal the angular momentum was shifted by one-half of planks constant. It has been long theorized that this could be the case but has never been proven before.
‘What I think is so exciting about this result is that even this fundamental property of light, that physicists have always thought was fixed, can be changed,’ said Professor Paul Eastham.
This discovery could have applications on quantum computing and fiber-optic data communications.