Broken Time Reversal of Light Interaction with Planar Chiral Nanostructures

We report unambiguous experimental evidence of broken time-reversal symmetry for the interaction of light with an artificial nonmagnetic material. Polarized color images of planar chiral gold-on-silicon nanostructures consisting of arrays of gammadions show intriguing and unusual symmetry: structures, which are geometrically mirror images, lose their mirror symmetry in polarized light. The symmetry of images can be described only in terms of antisymmetry (black-and-white symmetry) appropriate to a time-odd process. The effect results from a transverse chiral nonlocal electromagnetic response of the structure and has some striking resemblance with the expected features of light scattering on anyon matter.