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Q: Fachverband Quantenoptik und Photonik
Q 23: Poster 2: Intersectional Session
Q 23.8: Poster
Dienstag, 15. März 2011, 18:00–21:00, P1
Local Entropy Flow in Qubit Networks Under Random Controlled Unitary Transformations — •Jaroslav Novotny1,2, Gernot Alber1, and Igor Jex2 — 1Institut für Angewandte Physik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany — 2Department of Physics, FNSPE CTU in Prague, Czech Republic
The asymptotic dynamics of many-qubit quantum systems is investigated under iteratively applied random unitary transformations [1]. For a one-parameter family of controlled unitary transformations two main theorems are proved which characterize completely the dependence of this asymptotic dynamics on the topology of the interaction graph which encodes all possible qubit couplings. On the basis of these theorems the local entropy transport between an open quantum system and its environment are explored for strong non-Markovian couplings and for different sizes of the environment and different interaction topologies. In particular, the processes of thermalization and cooling of an open subsystem are investigated in detail. It is shown that both processes are possible if couplings between the subsystem and its environment act in both directions. If this condition is violated a successful realization of both processes is not possible.
References:
[1] J. Novotny, G. Alber, I. Jex, Cent. Eur. J. Phys. 8, 1001 (2010).