New exotic phenomena seen in photonic crystals
(PHYSorg.com Physics)

Topological effects, such as those found in crystals whose surfaces conduct electricity while their bulk does not, have been an exciting topic of physics research in recent years and were the subject of the 2016 Nobel Prize in physics. Now, a team of researchers at MIT and elsewhere has found novel topological phenomena in a different class of systems-open systems, where energy or material can enter or be emitted, as opposed to closed systems with no such exchange with the outside.