Design Of Single-Photon Mach-Zehnder Interferometer Based Devices For Quantum Information Processing

A comprehensive theoretical analysis of the cavity quantum electrodynamics (QED) in single-photon Mach-Zehnder Interferometer (SMZI) based switches and single quantum gates that are intended for the processing of quantum information encoded in the polarization of single photons inside integrated photonic crystal (PC) quantum networks is presented. These devices rely on manipulating the geometrical phase of single photons by means of the Single-Photon Faraday Effect (SPFE), which can be described in terms of a detuned single mode quantum field strongly interacting with a two-level system or quantum dot (QD) inside nanocavities. The feasibility of such devices depends on the ability for the field in each arm of the interferometer to couple in their respective nanocavities, successfully interact with the quantum dot, and when the appropriate phase is accumulated couple out; all these steps being performed with minimum phase error and losses. Using the Jaynes-Cummings model, the cavity dynamics is studied for various detuning energies and coupling energies, and it is shown that the design of these devices can achieve low phase error and robustness against fabrication errors