In this talk, I will discuss coherent control of cooperative light scattering on nuclei. Our work is motivated by the long standing quest for coherently controlling nuclear dynamics, and at the same time aims at developing non-classical and non-linear x-ray science.
In current experiments, synchrotron light in essence creates a single excitation coherently spread out over many nuclei in an excitonic state, which leads to cooperative effects such as superradiance and directionality of the scattered light. In ground-breaking experiments, basic coherent control of the cooperative emission was demonstrated , as well as the feasibility to implement advanced quantum optical coherence effects [2,3].
Based on these experimental setups, I will present a method to generate x-ray single-photon entanglement in nuclear forward scattering [4,5]. It operates by coherently controlling the scattering of a synchrotron pulse in such a way that a single excitation is split into two time-resolved entangled modes. As second application, I will discuss a method to control the cooperative spontaneous emission branching ratio in ensembles of nuclei, which is of relevance, e.g., for an efficient and controlled preparation of nuclear states . Finally, the engineering of advanced quantum optical level schemes in nuclei will be discussed.
 Y. V. Shvydko et al., Phys. Rev. Lett. 77, 3232 (1996).
 R. R hlsberger et al., Science 328, 1248 (2010).
 R. R hlsberger et al., Nature 482, 199 (2012).
 A. Pálffy, C. H. Keitel, and J. Evers, Phys. Rev. Lett. 103, 017401 (2009).
 A. Pálffy and J. Evers, J. Mod. Opt. 57, 1993 (2010).
 A. Pálffy, C. H. Keitel, and J. Evers, Phys. Rev. B 83, 155103 (2011).