# Measuring out-of-time-order correlations and multiple quantum spectra in a trapped-ion quantum magnet

@article{Grttner2016MeasuringOC, title={Measuring out-of-time-order correlations and multiple quantum spectra in a trapped-ion quantum magnet}, author={Martin G{\"a}rttner and Justin Gary Bohnet and Arghavan Safavi-Naini and Michael L. Wall and John J. Bollinger and Ana Maria Rey}, journal={Nature Physics}, year={2016}, volume={13}, pages={781 - 786} }

Controllable arrays of ions and ultracold atoms can simulate complex many-body phenomena and may provide insights into unsolved problems in modern science. To this end, experimentally feasible protocols for quantifying the buildup of quantum correlations and coherence are needed, as performing full state tomography does not scale favourably with the number of particles. Here we develop and experimentally demonstrate such a protocol, which uses time reversal of the many-body dynamics to measure…

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