title: Analogue of the quantum Hanle effect and polarization conversion in non-Hermitian plasmonic metamaterials.
abstract: The Hanle effect, one of the first manifestations of quantum theory introducing the concept of coherent superposition between pure states, plays a key role in numerous aspects of science varying from applicative spectroscopy to fundamental astrophysical investigations. Optical analogues of quantum effects help to achieve deeper understanding of quantum phenomena and, in turn, to develop cross-disciplinary approaches to realizations of new applications in photonics. Here we show that metallic nanostructures can be designed to exhibit a plasmonic analogue of the quantum Hanle effect and the associated polarization rotation. In the original Hanle effect, time-reversal symmetry is broken by a static magnetic field. We achieve this by introducing dissipative level crossing of localized surface plasmons due to nonuniform losses, designed using a non-Hermitian formulation of quantum mechanics. Such artificial plasmonic "atoms" have been shown to exhibit strong circular birefringence and circular dichroism which depends on the value of loss or gain in the metal-dielectric nanostructure.
authors.affiliation: Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom. pavel.ginzburg@kcl.ac.uk
authors.forename: Pavel
authors.initials: P
authors.lastname: Ginzburg
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Rodríguez-Fortuño
authors.forename: Alejandro
authors.initials: A
authors.lastname: Martínez
authors.forename: Anatoly V
authors.initials: AV
authors.lastname: Zayats
mesh_terms: D008670:Metals / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology; D011789:Quantum Theory; D020349:Surface Plasmon Resonance
chemical_list: D008670:Metals