Fisher information and multiparticle entanglement

  title={Fisher information and multiparticle entanglement},
  author={Philipp Hyllus and Wiesław Laskowski and Roland Krischek and Christian Schwemmer and Witlef Wieczorek and Harald Weinfurter and Luca Pezz'e and Augusto Smerzi},
  journal={Physical Review A},
The Fisher information F gives a limit to the ultimate precision achievable in a phase estimation protocol. It has been shown recently that the Fisher information for a linear two-mode interferometer cannot exceed the number of particles if the input state is separable. As a direct consequence, with such input states the shot-noise limit is the ultimate limit of precision. In this work, we go a step further by deducing bounds on F for several multiparticle entanglement classes. These bounds… 

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