Erlangen 2018 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 56: Quantum Information (Coherence and Entanglement)
Q 56.7: Talk
Thursday, March 8, 2018, 12:00–12:15, K 1.019
Characterizing entanglement with scrambled data — •Timo Simnacher1, Nikolai Wyderka1, Gael Sentís1, Rene Schwonnek2, and Otfried Gühne1 — 1Universität Siegen, Siegen, Germany — 2Leibniz Universität Hannover, Hannover, Germany
In an ordinary entanglement detection scenario, the possible measurements and the corresponding data are given. In contrast to device-independent scenarios, where the measurements are not characterized but the data have a clear interpretation, we consider the case where the measurements are characterized but the data is scrambled. That means, the assignment of outcomes to the corresponding probabilities is unknown.
As an example, we investigate the two-qubit scenario with local measurements of σx ⊗ σx and σz ⊗ σz. In this setting, we first find a class of entanglement witnesses invariant under permutation of probabilities and hence, it is indeed possible to detect entanglement even when the data is scrambled. Second, since entropies are naturally invariant under scrambling, it seems reasonable to consider entropic uncertainty relations to detect entanglement. Numerical and analytic results indicate that Shannon entropy is not suitable in this scenario, however, using Tsallis entropy Hq(pi) = 1/q−1 (1 − ∑i piq) is a promising approach for some q.