NOVEL PHOTONIC MATERIALS: Artificial material transforms itself from dielectric to metal
Experimental work led by physicists at Queens College, City University of New York (CUNY) in collaboration with City College of CUNY combined with theoretical work from Purdue University and the University of Alberta has uncovered a new method to manipulate light by borrowing an idea from the field of mathematical topology.
Experimental work led by physicists at Queens College, City University of New York (CUNY; Flushing, NY) in collaboration with City College of CUNY (New York, NY) combined with theoretical work from Purdue University (West Lafayette, IN) and the University of Alberta (Edmonton, AL, Canada) has uncovered a new method to manipulate light by borrowing an idea from the field of mathematical topology.1 The researchers have created an artificial material that can transform itself from a regular dielectric (a substance like glass or plastic that does not conduct electricity) to a medium that behaves like metal (reflects) in one direction and like a dielectric (transmits) in the other.
Optical properties of this artificial material can be mapped onto a topological transformation of an ellipsoidal surface into a hyperboloid. The topological transition from such a bound (elliptic) to an unbound (hyperbolic) surface manifests itself in the real world as a dramatic increase in the light intensity inside the material and increased rates of spontaneous emission of emitters positioned near the metamaterial. Altering the topology of the iso-frequency surface provides a fundamentally new route to manipulating light-matter interactions, with demonstrated modification of the light emission for a nanoparticle placed in the vicinity of the artificial material. Such media could find applications in solar cells, light-emitting diodes (LEDs), ultrasensitive sensors, and for quantum computers.
1. H.N.S. Krishnamoorthy et al., Science, 336, 6078, 205–209 (Apr. 13, 2012).