München 2004 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
Q: Quantenoptik und Photonik
Q 47: Quanteneffekte IV
Q 47.3: Talk
Friday, March 26, 2004, 11:30–11:45, HS 218
Fidelity for δ-kicked atoms at quantum resonance — •Sandro Wimberger1,2 and Andreas Buchleitner1 — 1Max-Planck-Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, D-01187 Dresden — 2International Centre for the Study of Dynamical Systems, Università degli Studi dell’ Insubria, Via Valleggio 11, I-22100 Como
A characteristic feature emanating from
classical chaos displays in the extreme sensitivity to
changes of the system’s parameters. On the quantum level, one
may therefore replace “sensitivity to initial conditions” by
“sensitivity to changes in the Hamiltonian” to characterise
the stability of quantum dynamics. A quantitative measure
of the stability of quantum states with respect to
changes in the Hamiltonian is the “fidelity”, the overlap
of two initially identical states which are exposed to distinct
evolutions [1].
We present analytical results on the time dependence of the
fidelity for an ensemble of δ-kicked atoms, at quantum resonance
conditions [2], and in experimentally feasible parameter ranges
[3]. While the fidelity saturates in absence of noise,
decoherence by spontaneous emission [2] leads to a decay whose
properties depend on the precise action of the noise.
A. Peres, Phys. Rev. A 30, 1610 (1984)
S. Wimberger et al., Nonlinearity 16, 1381 (2003)
S. Schlunk et al., Phys. Rev. Lett. 90, 054101 (2003)