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arXiv:cond-mat/0312202 · Physical Review B

Correlations in noisy Landau-Zener transitions

V. L. Pokrovsky, Stefan Scheidl

Published Jul 15, 2004• 6 citations
arXivHTMLPDF

Abstract

We analyze the influence of colored classical Gaussian noise on Landau-Zener transitions during a two-level crossing in a time-dependent regular external field. Transition probabilities and coherence factors become random due to the noise. We calculate their two-time correlation functions, which describe the response of this two-level system to a weak external pulse signal. The spectrum and intensity of the magnetic response are derived. Although the noise enters the equation of motion for the Bloch vector in a multiplicative way, nonperturbative analytic results are obtained by a resummation of diagrams in the limit of a short-noise correlation time. Our results also cover regimes where fluctuations are of the same order of magnitude as averages.

DOI
10.1103/physrevb.70.014416

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