Probing the response of quantum plasmonic systems: from the macroscopic to the microscopic

摘要

In this thesis we investigate the response of plasmonic systems in a quantum opticsudsetting. This work can be grouped into two sub-investigations, the study ofudmacroscopic and microscopic responses. The narrative of the thesis comprises threeudprincipal parts. First, we give an in-depth review of the field of quantum plasmonicsudas it is an important theme that runs through the work contained in this thesis. Inudparticular, we focus on outlining the cutting edge research that is being done on theudintense interactions between plasmonic systems and quantum emitters. This leadsudnaturally to the first investigation into the macroscopic response of quantum plasmonicudsystems in a metamaterial setting. We outline how complex hybrid systemsudof plasmonic metal nanoparticles (MNP) and two-level quantum dots (QD) can beudused to create a quantum plasmonic metamaterial. Metamaterials are structuresudcomposed of periodic lattices of identical subwavelength unit cell scatterers, each ofudwhich governs completely the electromagnetic properties of the entire bulk material.udWe theorize the use of MNP-QD nanorings as a unit cell in order to controludthe macroscopic magnetic properties of the metamaterial. We outline how such audmetamaterial can have a tunable, and saturable, magnetic permeability. In the lastudpart of the thesis we consider the model of a single light mode interacting ultrastronglyudwith a collection of emitters, in the anticipation that quantum plasmonicudsystems can be brought into this ultrastrong-coupling regime (USC). In particularudwe study the emission of the system after the coupling between the light mode andudthe emitters is non-adiabatically switched-on. We find evidence that for both two-level,udand multi-level, emitters in the USC, both the counter-rotating terms and theuddiamagnetic term must be included to prevent qualitative errors.