Freiburg 2019 – wissenschaftliches Programm
FM 11.3: Talk
Montag, 23. September 2019, 14:45–15:00, 2004
Reference-frame independent quantification of bipartite entanglement — •Michael Krebsbach, Heinz-Peter Breuer, and Andreas Ketterer — Physikalisches Institut, Albert-Ludwigs-Universität Freiburg
The experimental detection of entanglement usually involves a number of appropriately chosen local quantum measurements aligned with respect to a previously shared common reference-frame. Establishing the latter, however, requires the exchange of classical information which represents an additional technical overhead, in particular if the involved parties are in motion. In this work we investigate the reference-frame independent quantification of bipartite entanglement using moments of randomly measured correlation functions . In particular, we find that the concurrence of Bell-diagonal states is determined by the first three non-vanishing moments, a result that leads to lower bounds on the concurrence of general two-qubit states. Lastly, extensions of the presented methods to systems of larger local dimensions are considered as well.
 A. Ketterer, N. Wyderka, O. Gühne, Phys. Rev. Lett. 122, 120505 (2019).