Düsseldorf 2007 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 18: Quanteninformation (Verschränkung und Dekohärenz I)

Q 18.5: Talk

Tuesday, March 20, 2007, 11:45–12:00, 5L

Do NPT bound entangled states exist? — •Elisabeth Rieper and Reinhard Werner — Institut für Mathematische Physik, TU Braunschweig, www.imaph.tu-bs.de

The existence of NPT bound entangled states is equivalent to the existence of NPT Bound Werner states. A current conjecture is that 1-copy undistillable Werner states remain undistillable even for many copies. This would provide a large set of NPT bound entangled states. We investigate the distillation properties of these states with a new distillation protocol. We check for the maximal achievable fidelity of the output state by solving a generalized eigenvalue problem. By exploiting the symmetries of Werner states we find a new contraction scheme avoiding high dimensional matrices. This scheme enables us to test distillability of up to four copies. The numerical results for 1 to 4 copies support the above conjecture that undistillable Werner states are already 1-copy undistillable.