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TT: Tiefe Temperaturen

TT 22: Quantenkoh
ärenz und Quanteninformationssysteme I

TT 22.3: Vortrag

Mittwoch, 10. März 2004, 15:00–15:15, H19

Open systems dynamics in a spin star — •Daniel Burgarth¹, Heinz-Peter Breuer¹, and Francesco Petruccione^1,2 — ¹Physikalisches Institut, Universitaet Freiburg, Germany — ²Istituto Italiano per gli Studi Filosofici, Naples, Italy

The study of strongly coupled spin systems is important for various applications in quantum computation and quantum communication. The dynamics of a spin coupled to a spin bath is strongly influenced by dissipation and decoherence. Within the theory of open quantum systems the dynamics is described in terms of a master equation for the density matrix of the reduced spin degree of freedom.

A very simple, exactly solvable spin star system will be discussed and the reduced non-Markovian dynamics of the spin will be derived using different strategies of approximation. Particular attention will be devoted to the comparison of the non-Markovian approximations obtained by the Nakajima-Zwanzig and by the time-convolutionless projection operator technique.