QSpace Community:http://hdl.handle.net/1974/7842015-08-30T09:57:57Z2015-08-30T09:57:57ZTheory and applications of light-matter interactions in quantum dot nanowire photonic crystal systemsAngelatos, Gerasimoshttp://hdl.handle.net/1974/135262015-08-26T05:31:59Z2015-08-25T04:00:00ZTitle: Theory and applications of light-matter interactions in quantum dot nanowire photonic crystal systems
Authors: Angelatos, Gerasimos
Abstract: Photonic crystal slabs coupled with quantum dipole emitters allow one to control quantum light-matter interactions and are a promising platform for quantum information science technologies; however their development has been hindered by inherent fabrication issues. Inspired by recent nanowire growth techniques and opportunities in fundamental quantum nanophotonics, in this thesis we theoretically investigate light-matter interactions in nanowire photonic crystal structures with embedded quantum dots, a novel engineered quantum system, for applications in quantum optics. We develop designs for currently fabricable structures, including finite-size effects and radiative loss, and investigate their fundamental properties using photonic band structure calculations, finite-difference time-domain computations, and a rigorous photonic Green function technique. We study and engineer realistic nanowire photonic crystal waveguides for single photon applications whose performance can exceed that of state-of-the-art slab photonic crystals, and design a directed single photon source. We then develop a powerful quantum optical formalism using master equation techniques and the photonic Green function to understand the quantum dynamics of these exotic structures in open and lossy photonic environments. This is used to explore the coupling of a pair of quantum dots in a nanowire photonic crystal waveguide, demonstrating long-lived entangled states and a system with a completely controllable Hamiltonian capable of simulating a wide variety of quantum systems and entering a unique regime of cavity quantum electrodynamics characterized by strong exchange-splitting. Lastly, we propose and study a "metamaterial" polariton waveguide comprised of a nanowire photonic crystal waveguide with an embedded quantum dot in each unit cell, and explain the properties of both infinite and finite-sized structures using a Green function approach. We show that an external quantum dot can be strongly coupled to these novel waveguides, an achievement which has never been demonstrated in a solid-state platform.
Description: Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2015-08-25 16:11:19.2892015-08-25T04:00:00ZA Multi-wavelength Investigation of the Gas-rich Dwarf Galaxy Populations of Three Interacting Groups: NGC 3166/9, NGC 871/6/7 and NGC 4725/47Lee-Waddell, Karenhttp://hdl.handle.net/1974/135252015-08-26T05:23:53Z2015-08-25T04:00:00ZTitle: A Multi-wavelength Investigation of the Gas-rich Dwarf Galaxy Populations of Three Interacting Groups: NGC 3166/9, NGC 871/6/7 and NGC 4725/47
Authors: Lee-Waddell, Karen
Abstract: This thesis presents one of the first unbiased investigations of the first- and second-generation gas-rich dwarf galaxy populations of nearby interacting groups. Individually, these low-mass objects offer information about the evolutionary history of their respective groups. Collectively, the multi-wavelength dataset presented here enables direct comparison of the properties and prevalence of gas-rich dwarfs to those predicted by numerical simulations, particularly the tidal objects. Starting with HI maps from the blind Arecibo Legacy Fast ALFA survey (ALFALFA), three nearby groups: NGC 3166/9, NGC 871/6/7 and NGC 4725/47 were selected for high-resolution HI follow-up and deep optical imaging. Observations from the Giant Metrewave Radio Telescope (GMRT) are able to identify and resolve the HI belonging to the low-mass group members, thereby enabling gas and dynamical mass measurements. Deep g'r'i'-band optical photometry, from the Canada-France-Hawaii Telescope (CFHT) MegaCam, is used to infer the stellar masses, ages and metallicities of putative optical counterparts to these gas-rich detections. The combination of HI and optical data allows for dynamical to baryonic mass calculations and stellar population estimates that facilitate the distinction between and classification of dwarf irregulars (dIrrs), short-lived tidal knots and tidal dwarf galaxies (TDGs). Overall, the three groups in this study contain a total of eight spiral galaxies, at least eight dIrrs, four tidal knots (with M_HI ~ 10^7 M_sol) that are likely short-lived, and four tidal knots containing sufficient gas to survive and evolve into long-lived TDGs. This result implies that there are ~1.3 long-lived galaxy-like tidal features per interacting spiral galaxy pair, which is consistent with standard cosmological galaxy interaction simulations. The tidal objects examined in this survey also appear to have a wider variety of properties than the TDGs formed in current simulations, which could be the result of pre- or post-formation environmental influences.
Description: Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2015-08-13 15:13:00.1862015-08-25T04:00:00ZAnalytical modeling for transient probe response in eddy current testingDesjardins, Danielhttp://hdl.handle.net/1974/131212015-06-11T05:11:07Z2015-06-10T04:00:00ZTitle: Analytical modeling for transient probe response in eddy current testing
Authors: Desjardins, Daniel
Abstract: Analytical models that describe the electromagnetic field interactions arising between field generating and sensing coils in close proximity to conducting structures can be used to enhance analysis and information extracted from signals obtained using electromagnetic non-destructive evaluation technologies. A novel strategy, which enables the derivation of exact solutions describing all electromagnetic interactions arising in inductively coupled circuits due to a voltage excitation, is developed in this work. Differential circuit equations are formulated in terms of an arbitrary voltage excitation and of the magnetic fields arising in inductive systems, using Faraday’s law and convolution, and solved using the Fourier transform. The approach is valid for systems containing any number of driving and receiving coils, and include nearby conducting and ferromagnetic structures. In particular, the solutions account for feedback between a ferromagnetic conducting test piece and the driving and sensing coils, providing correct voltage response of the coils. Also arising from the theory are analytical expressions for complex inductances in a circuit, which account for real (inductive) and imaginary (loss) elements associated with conducting and ferromagnetic structures. A novel model-based method for simultaneous characterization of material parameters, which includes magnetic permeability, electrical conductivity, wall thickness and liftoff, is subsequently developed from the forward solutions. Furthermore, arbitrary excitation waveforms, such as a sinusoid or a square wave, for applications in conventional and transient eddy current, respectively, may be considered. Experimental results, obtained for a square wave excitation, are found to be in excellent agreement with the analytical predictions.
Description: Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2015-06-09 18:41:03.0042015-06-10T04:00:00ZQuantum Nonlinear Optics in Lossy Coupled-Cavities in Photonic Crystal SlabsKamandar Dezfouli, MOHSENhttp://hdl.handle.net/1974/131052015-06-02T15:40:38Z2015-06-02T04:00:00ZTitle: Quantum Nonlinear Optics in Lossy Coupled-Cavities in Photonic Crystal Slabs
Authors: Kamandar Dezfouli, MOHSEN
Abstract: A general formalism is developed that can be used to obtain photon dynamics in coupled-cavity system in leaky photonic crystal slabs. This is accomplished using a non-Hermitian projection operator, where the coupled-cavity modes, known as quasimodes, are used as a basis. Because of this, intrinsic features of these quasimodes such as the leakage and the non-orthogonality are included in a self-consistent manner. The projection technique can be used to represent the Hamiltonian of a typical system in the basis of the quasimodes. In addition, the corresponding quantum Master equation and adjoint quantum Master equation are provided. By employing these, the time dependence of the density matrix and Heisenberg operators can be obtained.
In particular, a multimode Jaynes-Cummings Hamiltonian is obtained for photonic crystal slabs interacting with multiple quantum dots. As a proof of principle, a simple system with two quasimodes is considered, where the mode non-orthogonality affects the photon dynamics in a non-trivial manner. It is shown that, while the number of photons in each quasimode decays off, it also oscillates due to the quasimode non-orthogonality.
Using the same projection technique, the problem of nonlinear photon pair generation via spontaneous four-wave mixing in photonic crystal slabs is discussed. The main objective is to examine the effect of loss on pair generation in systems such as photonic molecules and coupled-resonator optical waveguides. Several conclusion are made. In addition to the overall loss rates of the pump, signal and idler photons, the loss difference between signal and idler channels plays an important role in minimizing the number of unpaired photon in the system. Also, there is a trade-off between source brightness and higher order generation depending on the losses in the system. This is important, because both the number of unpaired photons and the number of multiple photon pairs degrade device performance. Moreover, when slow light devices are considered, the probability of finding photon pairs at particular locations is affected both by the dispersive behavior of the waveguide and the lossy behavior. This is important as it opens up different possible design strategies that one might want to use in lossy systems.
Description: Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2015-06-02 11:02:20.7182015-06-02T04:00:00Z