Dresden 2009 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 15: Quantum chaos I

DY 15.3: Talk

Wednesday, March 25, 2009, 14:45–15:00, HÜL 386

Coupling fidelity in a microwave billiard — •Bernd Köber¹, Ulrich Kuhl¹, Hans-Jürgen Stöckmann¹, Dmitry Savin², Thomas Gorin³, and Thomas Seligman⁴ — ¹Fachbereich Physik, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany — ²Department of Mathematical Sciences, Brunel University, Uxbridge UB8 3PH, UK — ³Departamento de Fisica, Universidad de Guadalajara, Guadalajara C.P. 44840, Jalisco, Mexico — ⁴Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Cuernavaca, Mexico

We investigate the scattering fidelity in a microwave billiard. In former studies we found for global perturbation an agreement with prediction from random matrix theory[1], whereas in case of a local perturbation an algebraic decay was found[2]. In this presentation we use the coupling to an external channel as a perturbation parameter, which is inherent to systems to be used for quantum computing. We derive an exact formula using an supersymmetrical ansatz and compare it with experiments in an chaotic billiard, where the coupling of a channel was changed by means of an slit. Again an algebraic decay for large times is found and the experiment confirms this findings.

[1] R. Schäfer, H.-J. Stöckmann, T. Gorin, and T. H. Seligman, Phys. Rev. Lett. 95, 184102 (2005).

[2] R. Höhmann, U. Kuhl, and H.-J. Stöckmann. Phys. Rev. Lett. 100, 124101 (2008).