Magnifying the Photonic Spin Hall Effect
Everybody is familiar with light bending when it enters a material, typically because the material refracts the light. That is not the only way a material can cause light to turn, but these other means can be very hard to see because of how weak they are. Metamaterials however, which have unnatural optical properties, can bring these effects out, and such as those used by researchers at Berkeley Lab.
The spin Hall effect is something long known to affect electrons; it causes them to curve in some materials because of their spin state, similar to how a spinning baseball will curve in the air. Photons also have spin states, but it has a weaker effect on a photon, which is why the researchers built a special array of antennas. This array amplified the photonic spin Hall effect by causing it to turn as it propagates through the metamaterial, and the Hall effect depends on the curvature of the photons' path. This resulted in photons of different polarizations deviating enough to be captured with a simple camera.
While this research may have little influence on modern electronic computers, future optical ones could see benefits because of how it linked the path of the photons to their polarization. As polarization can be used to store information, this research could potentially be applied to encode and control information carried by photons.
Source: Berkeley Lab