Master Thesis Defense by Johann Kollath-Bönig

Cavity-based quantum memory for light with inhomogeneously coupled atoms

Optically controlled, cavity-based quantum memories with Λ-type atomic media have been proposed for efficient storage of single-mode light pulses. In this thesis, we investigate the effect of inhomogeneous coupling between the light field and the storage medium on the efficiency. For this purpose, we develop a perturbative method for analytical solutions of the maximum retrieval efficiency. Furthermore, the optimal strategy for storage followed by retrieval is analyzed. In both cases, we mainly consider inhomogeneous samples drawn from Gaussian probability distributions, which determine the atomic Rabi oscillations, coupling constants and detunings. While samples with inhomogeneous coupling constants do not lead to a reduced efficiency compared to the homogeneous case, we show that the opposite is true for samples with inhomogeneous Rabi oscillations or inhomogeneous broadening. Moreover, we find that the optimal strategy for samples with inhomogeneous Rabi oscillations is to apply on-resonant light fields. For inhomogeneously broadened media the optimal strategy is independent of the applied laser detuning.