Fei Wang

A sheet of graphene, a carbon lattice just one atom thick, under a powerful laser beam behaves like a road where a toll barrier suddenly appears. Electrons that were freely racing through the material suddenly hit a forbidden zone: an energy gap they cannot leap across. This was predicted theoretically before, but no one had ever seen it directly.

A candle flame flickers in a draft but doesn't go out — the tongue of fire briefly changes shape and then returns. Optical skyrmions behave much the same way — tiny vortices in a light beam, reminiscent of swirling eddies. Until recently, they were created only in the perfect, smooth light of a laser.