Berlin 2012 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 18: Transport: Quantum Coherence and Quantum Information Systems 2 (jointly with TT, MA)

HL 18.2: Talk

Monday, March 26, 2012, 15:15–15:30, BH 243

Relaxation and decoherence dynamics in the spin-boson model — •Oleksiy Kashuba, Mikhail Pletyukhov, Dirk Schuricht, and Herbert Schoeller — Institut für Theorie der statistischen Physik, RWTH Aachen, D-52056 Aachen

We study the real-time dynamics of the ohmic spin-boson model using a nonequilibrium renormalisation group method [1] successfully applied to the anisotropic Kondo model [2] and the interacting resonant-level model [3]. We discuss the relaxation and decoherence channel w/o bias. In all regimes of the coupling α, we obtain power law time dependence from non-Markovian contributions but always accompanied by exponential decay. For α∼ 1/2, we recover the well-known localization transition but obtain different power-law exponents for the time evolution in the biased case. Finally, for α∼ 1, we discuss the time-evolution close to a quantum critical point.
H. Schoeller, Eur. Phys. J. Spec. Top. 168, 179 (2009).
M. Pletyukhov, D. Schuricht and H. Schoeller, Phys. Rev. Lett. 104, 106801 (2010).
S. Andergassen, M. Pletyukhov, D. Schuricht, H. Schoeller, and L. Borda, Phys. Rev. B 83 205103 (2011).