Magneto-optical chirality in a coherently coupled exciton-plasmon system

Abstract

Chirality is a fundamental asymmetry phenomenon, with chiral optical elements exhibiting asymmetric response in reflection or absorption of circularly polarized light. Recent realizations of such elements include nanoplasmonic systems with broken mirror symmetry and polarization-contrasting optical absorption known as circular dichroism. An alternative route to circular dichroism is provided by spin-valley polarized excitons in atomically thin semiconductors. In the presence of magnetic fields, they exhibit an imbalanced coupling to circularly polarized photons and thus circular dichroism. Here, we demonstrate that polarization-contrasting optical transitions associated with excitons in monolayer WSe${}_2$ can be transferred to proximal plasmonic nanodisks by coherent coupling. The coupled exciton-plasmon system exhibits magneto-induced circular dichroism in a spectrally narrow window of Fano interference, which we model in a master equation framework. Our work motivates exciton-plasmon interfaces as building blocks of chiral metasurfaces for applications in information processing, non-linear optics and sensing.

6 pages, 4 figures; 10 pages Supplementary Information

References in corpus (12)

• The Quantum Internet
• Valley polarization in MoS2 monolayers by optical pumping
• Strong light-matter coupling in two-dimensional atomic crystals
• Magnetic Control of Valley Pseudospin in Monolayer WSe2
• Valley Zeeman Effect in Elementary Optical Excitations of a Monolayer WSe2
• Semiconductor-metal nanoparticle molecules: hybrid excitons and non-linear Fano effect
• Valley Splitting and Polarization by the Zeeman Effect in Monolayer MoSe2
• Robust optical emission polarization in MoS2 monolayers through selective valley excitation
• Cooperative resonances in light scattering from two-dimensional atomic arrays
• Nanoscale chiral valley-photon interface through optical spin-orbit coupling
• Realization of an atomically thin mirror using monolayer MoSe2
• Magneto-optics in transition metal diselenide monolayers