%0 Generic
%A Kong, Xiangjin
%C Heidelberg, Germany
%D 2016
%F heidok:21709
%R 10.11588/heidok.00021709
%T Collective effects of nuclei in single x-ray photon superradiance
%U https://archiv.ub.uni-heidelberg.de/volltextserver/21709/
%X This thesis is dedicated to the study of collective effects of nuclei in single x-ray photon superradiance. To this end we investigate aspects of superradiance in both nuclear forward scattering and in thin-film cavities with an embedded 57Fe nuclear layer. A general theoretical framework is developed to investigate a single-photon cooperative emission from a cloud of resonant systems, atoms or nuclei, in the presence of magnetic hyperfine splitting. In the limit of a thick sample, we present our results for two means to coherently control the collective  single x-ray photon emission in nuclear forward scattering. In the limit of a thin sample in a thin-film cavity with embedded resonant nuclei, we find out that unlike the magnetic hyperfine splitting of a single atom or nucleus, interesting collective effects may occur which modify the hyperfine level structure. In addition, for a certain parameter regime a spectrum reminiscent of electromagnetically induced transparency (EIT) can be achieved. Based on this EIT-like effect, a theoretical control mechanism for stopping x-ray pulses in the thin-film x-ray cavity is put forward. Finally, we show theoretically that for the case of two nuclear ensembles  in the thin-film cavity, pseudo-Rabi splitting due to the strong coupling between the two layers should occur. The latter findings are confirmed by preliminary experimental data.