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Q: Fachverband Quantenoptik und Photonik
Q 9: Quanteninformation: Konzepte II
Q 9.6: Talk
Monday, March 2, 2009, 15:15–15:30, VMP 6 HS-D
Measuring mixed-state entanglement via antilinear operators — •Oliver Viehmann1, Jens Siewert1, Andreas Osterloh2, and Armin Uhlmann3 — 1Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg — 2Institut für Theoretische Physik, Universität Hannover, 30167 Hannover — 3Institut für Theoretische Physik, Universität Leipzig, 04109 Leipzig
The amount of entanglement in mixed quantum states is commonly defined via the convex-roof extension of a certain pure state entanglement measure, e.g., a polynomial invariant such as the concurrence [1]. For a pair of qubits, the convex roof of the pure-state concurrence can be obtained analytically [2].
The Wootters-Uhlmann method depends crucially on the properties of antilinear operators. In this contribution, we investigate a possible generalization of the Wootters-Uhlmann method for invariants which can be written as expectation values of antilinear operators with respect to multiple copies of a given pure state. In particular, we try to apply this method to invariants of polynomial degree 4 such as the three-way tangle.
W. K. Wootters, Phys. Rev. Lett. 80, 2245 (1998).
A. Uhlmann, Phys. Rev. A 62, 032307 (2000).