Master Thesis Defense by David Cirauqui Garcia – University of Copenhagen

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Master Thesis Defense by David Cirauqui Garcia

Efficient, ultra-fast photon storage is one of the basic requirements for building a quantum computer and process quantum information. Several schemes for a quantum memory have been proposed, but none based on optomechanical systems. These systems are known to have very long coherence times, and thus are a promising architecture. In this thesis, we consider an optical cavity with an optomechanical membrane as a mirror, and study how a single photon couples to the vibrational motion. We control this storage process by means of a coherent light field, which we optimise in the adiabatic regime. We explore the non-adiabatic regime numerically and develop a mathematical framework that allows us to study it analytically. Our mathematical method is not restricted to an optomechanical cavity, and can easily be extended to other physical systems. With the analytical results derived, we can give a recipe for a better optimisation of the non-adiabatic storage of photons. In particular, we find a class of single photon shapes that performs better than all others, with which the adiabatic condition is fulfilled for shorter timescales.