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MP: Theoretische und Mathematische Grundlagen der Physik

MP 4: Poster 1

MP 4.4: Poster

Mittwoch, 29. März 2006, 15:30–16:00, Foyer

Fidelity freeze for orthogonal random matrix models — •H. Kohler¹ and H. J. Stöckmann² — ¹Universität Heidelberg — ²Universität Marburg

The concept of fidelity has been introduced to characterize the stability of a quantum-mechanical system against perturbations. The fidelity amplitude is defined as the overlap integral of a wave packet with itself after the development forth and back under the influence of two slightly different Hamiltonians. It was shown by Prosen and Znidaric in linear-response approximation that the decay of the fidelity is frozen if the Hamiltonian of the perturbation contains off-diagonal elements only. In the present work the linear response results are extended by a supersymmetry calculation to arbitrary strengths of the perturbation for the case that the perturbation is a hermitean or a purely imaginary matrix.