@misc{7a4571d3769641e192525f323da364bf,
title = "Quantum Nonlinear Nano-optics in Hybrid Polaritonic Systems",
abstract = "In this thesis, we theoretically investigate light-matter interactions in hybrid nanostructures. We present the theory of classical electrodynamics and quantum electrodynamics in nanophotonics. We do so in order to propose and analyze novel phenomena in systems consisting of atoms and nanostructures supporting polaritonic resonances. We primarily investigate polaritonic nanostructures such as metallic nanostructures and two-dimensional nanostructures in the form of isotropic and gyrotropic graphene. Hybrid nanostructures consisting of polaritonic materials like these have emerged as the building blocks in applications within sensing, quantum communication and computation.Starting with reviewing the fundamentals of classical nanophotonics, we introduce the theory necessary to study plasmonic resonances in both metallic nanostructures and graphene. We present the magneto-optical response of graphene when a static magnetic field is acting orthogonally on the graphene sheet, and we consider the plane wave illumination of magneto-optical nanostructured graphene. We find a semi-analytical formalism to consider the magneto-optical response of graphene nanodisks at large temperatures and propose self-hybridization in the form of thermal magnetoplasmons in such systems. We then propose to use such magneto-optical graphene disks in a Salisbury screen to achieve a chiral perfect absorber and a chiral thermal emitter.Turning to quantum emitters in nanophotonic environments, we introduce the basics of macroscopic quantum electrodynamics to facilitate the exploration of the quantum electrodynamic corrections in quantum emitters in lossy environments. We do this by investigating the spontaneous decay rate enhancement and the photonic Lamb shift in such emitters. Going beyond the classical and local response of metallic nanostructures, we employ the surface response function formalism to correct the local response of gold metal nanostructures. Here, we derive analytical expressions for how these nonlocal and quantum mechanical corrections influences the emission properties of nearby quantum emitters. We show that these corrections are large when considering thin gold shells or films, and when the gold medium interfaces high-index dielectrics. We then consider positioning a quantum emitter close to gyrotropic graphene. Here, we see that the Shubnikov-de-Haas oscillations present in the optical response of magneto-optical graphene is reflected in the Purcell enhancement factor of quantum emitters close to a graphene sheet with an incident static magnetic field. We then develop the numerical and semi-analytical methods to find the optical response of nanostructured gyrotropic graphene in the form of nanoribbons and nanodisks to dipolar sources in the quasistatic regime. For quantum emitters close to a gyrotropic graphene nanoribbon, we show chirality in the system in the form of a large discrepancy between the Purcell factor of a right-hand circularly polarized dipole versus a left-hand circularly polarized dipole. For a circularly polarized dipole close to a nanoribbon we also show controllable and unidirectional emission into the graphene ribbon, which is of interest as waveguides in quantum networks. Lastly, we also consider the strong chiral emission by circularly polarized dipoles above gyrotropic graphene nanodisks. Considering a driven system consisting of a two-level atom above an isotropic graphene sheet, we show that this system exhibits bistability and electro-optical hysteresis loops in the population dynamics of the atom. This is derived within a semi-classical formalism, and we show that the bistability may be observed in phenomena such as the total far field radiation power, resonance fluorescence of the light scattered by the atom, as well as the photon statistic of the emitted light. The system also exhibits critical slowing down around critical points in the hysteresis loops.",
keywords = "Nanophotonics, Quantum Electrodynamics, Graphene, Quantum Plasmonics, Nonlocal Response, Magnetoplasmon, Chirality, Nanofotonik, Kvanteelektrodynamik, Grafen, Magnetoplasmon, Kiralitet",
author = "Eriksen, {Mikkel Have}",
year = "2025",
month = jan,
day = "16",
doi = "10.21996/84vs-qg76",
language = "English",
publisher = "Syddansk Universitet. Det Tekniske Fakultet",
address = "Denmark",
school = "SDU",
}