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Q: Fachverband Quantenoptik und Photonik
Q 36: Quanteninformation (Konzepte und Methoden II)
Q 36.8: Talk
Thursday, March 13, 2008, 12:45–13:00, 1B
Quantum evolution from a snapshot — •Michael Wolf1, Jens Eisert2, Toby Cubitt3, and Ignacio Cirac1 — 1Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str.1, 85748 Garching — 2Institute for Mathematical Sciences, Imperial College London — 3Department of Mathematics, University of Bristol
We investigate what a snapshot of a quantum evolution - a quantum channel reflecting open system dynamics - reveals about the underlying continuous time evolution. Remarkably, from such a snapshot, and without imposing additional assumptions, it is possible to decide whether or not a channel is consistent with a time (in)dependent Markovian evolution, for which we provide computable necessary and sufficient criteria. Based on these, a computable measure of 'Markovianity' is introduced which quantifies the Markovian part of a quantum channel. We discuss the consistency with Markovian dynamics as encountered in quantum process tomography for physical non-Markovian processes. The results clarify the geometry of the set of quantum channels with respect to being solutions of time (in)dependent master equations or (in)divisible channels.