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TT: Fachverband Tiefe Temperaturen

TT 13: Transport: Poster Session

TT 13.39: Poster

Monday, March 26, 2012, 15:00–19:00, Poster B

Dynamics and decoherence in the Gaudin model — •Daniel Stanek, Carsten Raas, and Götz S. Uhrig — Technische Universität Dortmund, Lehrstuhl für Theoretische Physik I, 44221 Dortmund

The Gaudin or central spin model describes a single qubit which interacts with a bath of non-interacting spins 1/2, e.g., nuclear spins in a quantum dot. The model is widely applied in the fields of nuclear magnetic resonance and quantum information processing.

Using time-dependent density matrix renormalization group (tDMRG), we calculate the time-evolution of the qubit which is initialized in a well-defined state out of equilibrium. A detailed analysis of the longitudinal as well as of the transverse relaxation of the qubit for various distributions of the couplings between bath and qubit is presented. In addition, we discuss different initial states of the bath and their influence on the decoherence of the qubit.