Hannover 2010 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
Q: Fachverband Quantenoptik und Photonik
Q 22: Quantum Effects: Entanglement and Decoherence II
Q 22.6: Talk
Wednesday, March 10, 2010, 11:45–12:00, A 310
Detection of avoided crossings by fidelity — •Patrick Plötz1,2, Michael Lubasch1,2,3, and Sandro Wimberger1,2 — 1Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 19, 69120 Heidelberg — 2Heidelberg Graduate School of Fundamental Physics, Albert-Ueberle-Str. 3-5, 69120 Heidelberg — 3Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching
The overlap of eigenstates of two slightly different Hamiltonians—the fidelity—is proposed as an easy-to-use detector of avoided crossings in the energy spectrum [1]. It has been used to detect quantum phase transitions in the ground state of many-body quantum systems, and we lift its application to the complete energy spectrum. The value of this new Hilbert space measure for characterising complex quantum spectra is underlined by spectral analysis of many-body Bose–Hubbard systems.
[1] P. Plötz, M. Lubasch, and S. Wimberger, Detection of avoided crossings by fidelity, arXiv:0909.4333v1 [quant-ph].