Regensburg 2004 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 22: Quantenkoh
ärenz und Quanteninformationssysteme I

TT 22.4: Vortrag

Mittwoch, 10. März 2004, 15:15–15:30, H19

Decoherence due to aging 1/f noise — •Josef Schriefl^1,2, Maxime Clusel², David Carpentier², and Pascal Degiovanni² — ¹Institut für theoretische Festkörperphysik, Universität Karlsruhe, 76128 Karlsruhe, Germany — ²Laboratoire de Physique de l’Ecole Normale Supérieure de Lyon, UMR 5672, 69007 Lyon, France

We propose a novel phenomenological model for 1/f^µ noise due to collective excitations of interacting defects in glassy systems. At very low temperatures the effective dynamics of these collective modes are very slow, leading to non-stationarity and pronounced non-Gaussian features of the noise. The induced dephasing, therefore, depends qualitatively on the age of the noise. In the case of longitudinal coupling to a two-level system (e.g. a qubit)we find exact expressions for the decoherence factor in various regimes.