Emil Zeuthen – Niels Bohr Institute - University of Copenhagen


Emil ZeuthenEmil Zeuthen

A thesis submitted December 2015 for the degree of Doctor of Philosophy and defended January 21, 2016.

The PhD School of Science
Faculty of Science
Niels Bohr Institute, Quantum Optics, University of Copenhagen

Anders S. Sørensen

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Electro-optomechanical transduction & Quantum hard-sphere model for dissipative Rydberg-EIT media

This theoretical thesis consists of two parts which concern rather different topics belonging to the field of quantum optics.

Using the techniques of optomechanics, there has been significant recent progress in coupling nano- and micro-scale mechanical oscillators to electromagnetic radiation modes ranging from radio to optical frequencies. By arranging two such couplings in tandem, a high-Q mechanical oscillator can serve as an efficient transducer between electromagnetic modes of different frequencies. This approach has successfully been exploited for frequency conversion of classical signals [1] and also has the potential of enabling quantum state transfer between superconducting circuitry and traveling optical signals.

In this thesis we present a detailed theoretical escription of the interconversion between itinerant radiation modes using an intermediary mechanical mode. In order to characterize the performance of such transducers, suitable figures of merit must be established. We find here that a transducer can be characterized by two key parameters, the signal transfer efficiency  and added noise N. In terms of these, we evaluate its performance in various tasks ranging from classical signal detection to quantum conversion for quantum communication and information processing applications.

Continue the abstract in the thesis.

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