Europhys. Lett.
Volume 69, Number 2, January 2005
Page(s) 156 - 162
Section General
Published online 15 December 2004
Europhys. Lett., 69 (2), pp. 156-162 (2005)
DOI: 10.1209/epl/i2004-10324-1

Nonstationary dephasing of two-level systems

J. Schriefl1, 2, M. Clusel1, D. Carpentier1 and P. Degiovanni1

1  CNRS-Laboratoire de Physique de l'École Normale Supérieure de Lyon 46 Allée d'Italie, 69007 Lyon, France
2  Institut für Theoretische Festkörperphysik, Universität Karlsruhe 76128 Karlsruhe, Germany

received 8 June 2004; accepted in final form 5 November 2004
published online 15 December 2004

We investigate the influence of nonstationary $1/f^{\mu}$ noise, produced by interacting defects, on a quantum two-level system. Adopting a simple phenomenological model for this noise we describe exactly the corresponding dephasing in various regimes. The nonstationarity and pronounced non-Gaussian features of this noise induce new anomalous dephasing scenarii. Beyond a history-dependent critical coupling strength, the dephasing time exhibits a strong dependence on the age of the noise and the decay of coherence is not exponential.

03.65.Yz - Decoherence; open systems; quantum statistical methods.
73.23.-b - Electronic transport in mesoscopic systems.

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