Lossy atomic photonic crystals can be suitably tailored so that the real and imaginary parts of the susceptibility are, respectively, an odd and an even function of position. Such a parity-time (PT) space antisymmetry in the susceptibility requires neither optical gain nor negative refraction, but is rather attained by a combined control of the spatial modulation of both the atomic density and their dynamic level shift. These passive photonic crystals made of dressed atoms are characterized by a tunable unidirectional reflectionlessness accompanied by an appreciable degree of transmission. Interestingly, such peculiar properties are associated with non-Hermitian degeneracies of the crystal scattering matrix, which can then be directly observed through reflectivity measurements via a straightforward phase modulation of the atomic dynamic level shift and even off resonance.
|Titolo:||Parity-time-antisymmetric atomic lattices without gain|
|Data di pubblicazione:||2015|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1103/PhysRevA.91.033811|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Parole Chiave:||ELECTROMAGNETICALLY INDUCED TRANSPARENCY; NON-HERMITIAN HAMILTONIANS; EXCEPTIONAL POINTS; PHOTONIC CRYSTAL; OPTICAL LATTICES|
|Appare nelle tipologie:||1.1 Articolo in rivista|