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arXiv · 1909.06233

Certifying the purity of quantum states with temporal correlations

Cornelia Spee
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Abstract

Correlations obtained from sequences of measurements have been employed to distinguish among different physical theories or to witness the dimension of a system. In this work we show that they can also be used to establish semi-device independent lower bounds on the purity of the initial quantum state or even on one of the post-measurement states. For single systems this provides information on the quality of the preparation procedures of pure states or the implementation of measurements with anticipated pure post-measurement states. For joint systems one can combine our bound with results from entanglement theory to infer an upper bound on the concurrence based on the temporal correlations observed on a subsystem.

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Cornelia Spee. 2019-09-13. Certifying the purity of quantum states with temporal correlations. https://doi.org/10.1103/physreva.102.012420

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