Abstract:
Quantum optics provides powerful means to probe quantum mechanics. In this
thesis, we study various aspects of quantum phenomena arising in quantum optical
systems. Part I studies broadband quantum teleportation. After presenting three
different methods of analyzing the standard teleportation protocol, we study the
interplay between various bandwidths in determining the fidelity of a broadband
quantum field teleportation. Explicit formulae for the degrees of first- and secondorder
coherence for the teleportation of resonance fluorescence are derived for this
purpose. Part II studies entanglement arising in cascaded open quantum (optical)
systems. First, a detailed laser model is produced within quantum trajectory theory
to study the total decoherence rate of a laser-driven qubit. Second, using this model,
we address the issue of laser quantum state, viewed in connection with separability
of the laser-driven-qubit system. Third, a measure of entanglement within quantum
trajectory theory called ‘Contextual Entanglement’ is calculated for a few simple
systems and compared with the ‘Entanglement of Formation’. Lastly, we introduce
a method to quantify entanglement (based on the contextual entanglement) between
a source and the field it emits, which we call the ‘Entanglement Spectrum’. It is
applied to study the entanglement between a laser-driven qubit and the field the
qubit scatters.