6533b7d4fe1ef96bd1262fdd

RESEARCH PRODUCT

Quantum Nanoplasmonic : from dressed atom picture to superradiance

subject

description

Controlling quantum emitters (atoms, molecules, quantum dots, etc.), light, and its interactions is a key issue for implementing devices for information optical processing at the quantum level. For example, controlling dynamics of emitters coupled to a high-Q cavity can be achieved through cavity quantum electrodynamics (cQED). Plasmonic structures hybrid system are of growing interest in the quantum control at the nanoscale because of their capability to confine light beyond the diffraction limit. However, its application appears notoriously limited in practical situations due to the intrinsic presence of numerous and lossy modes, which complicates the description and the interpretation of the interaction, and introduces strong decoherence in the system. The subject of this thesis concerns the quantum description of the coupling between one or more emitters and localized surface plasmon of a metallic nano-particle. This work is essentially theoretical and numerical and relies on an effective model dedicated to quantum plasmonics and making the link with cavity quantum electrodynamics. The underlying effective Hamiltonian is built via the modal decomposition of the local density of states of the emitter in the presence of the nano-particle. This leads to the definition of plasmonic pseudo-modes including strong losses. Introducing an environnement allows to derive an effective master equation where the radiation modes are the source of Fano lineshape of the resonance profiles that occurs when the nano-particule becomes large enough. By means of this effective model we have studied the dynamic of the collective emission of emitters in the weak coupling regim. According to the spatial configuration of the emitters, we observe superradiance enhancement (Purcell effect) or blockade. We also investigate the strong coupling regime for which the hybrid system emitters+nano-particle is described in the dressed atom picture.