Projects per year
Abstract
The main topic of this thesis revolves around quantum measurement. We illustrate how two different views of quantum objects, the discreteand continuousvariable views, can be combined to more effectively distinguish between orthogonal states. Such combined measurements are referred to as hybrid. The discretevariable view is more appropriate to probe energy eigenstates. However, when two or more energy eigenstates are superposed, accurate measurements in the energy eigenbasis require rotations in phase space which are very unwieldy as they require strong nonlinearities and
elaborate interactions between light and matter. On the other hand, energy eigenstate superpositions carry a continuous relative phase which is easily probed by continuousvariable interference measurements such as homodyning. The tradeoff between photon counting and homodyning is in practice determined by feasibility studies. This is what we do for two particular applications of quantum measurements: Bell tests and the amplication of Schrödinger cat states. This project also had an experimental component which was supposed to produce highfidelity Schrödinger cat states. This
goal turned out to be hampered by noise from the laser as well as a series of anomalous behavior of the nonlinear crystal whereby no classical deamplification, and therefore no squeezing, could be observed.
elaborate interactions between light and matter. On the other hand, energy eigenstate superpositions carry a continuous relative phase which is easily probed by continuousvariable interference measurements such as homodyning. The tradeoff between photon counting and homodyning is in practice determined by feasibility studies. This is what we do for two particular applications of quantum measurements: Bell tests and the amplication of Schrödinger cat states. This project also had an experimental component which was supposed to produce highfidelity Schrödinger cat states. This
goal turned out to be hampered by noise from the laser as well as a series of anomalous behavior of the nonlinear crystal whereby no classical deamplification, and therefore no squeezing, could be observed.
Original language  English 

Publisher  Department of Physics, Technical University of Denmark 

Number of pages  131 
Publication status  Published  2013 
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Projects
 1 Finished

Quantum Information Processing with Schrödinger Cat States
Laghaout, A., Andersen, U. L., Brusch, A., Bourennane, M. & Marquardt, C. D.
15/03/2010 → 30/08/2013
Project: PhD