]> BibSonomy publications for /bibtex/1b54f2a307dd0bab83b802f43f5b99c4f http://www.bibsonomy.org/burst/bibtex/1b54f2a307dd0bab83b802f43f5b99c4f BibSonomy BuRST Feed for /bibtex/1b54f2a307dd0bab83b802f43f5b99c4f 2008-07-27T03:22:20+02:00 Robustness of adiabatic passage through a quantum critical point http://www.bibsonomy.org/bibtex/203d506efc28e5d8a5c4f1a3ecc9e0145/statphys23 statphys23 2007-06-20T10:16:09+02:00 adiabatic dynamics models noise passage phase quantum spin statphys23 topic-8 transitions
Robustness of adiabatic passage through a quantum critical point
A. Fubini and G. Falci and A. Osterloh Abstract Book of the XXIII IUPAP International Conference on Statistical Physics (2007)
to adiabatic dynamics models noise passage phase quantum spin statphys23 topic-8 transitions by statphys23 on 2007-06-20 10:16:09 ]]> Genova, ItalyAbstract Book of the XXIII IUPAP International Conference on Statistical Physics9-13 JulyRobustness of adiabatic passage through a quantum critical point2007adiabatic dynamics models noise passage phase quantum spin statphys23 topic-8 transitions 2007-06-20 10:16:09.0We analyze the crossing of a quantum critical point based on exact results for the transverse XY model. In dependence of the change rate of the driving field, the evolution of the ground state is studied while the transverse magnetic field is tuned through the critical point with a linear ramping. The excitation probability is obtained exactly and is compared to previous studies and to the Landau-Zener formula, a long time solution for non-adiabatic transitions in two-level systems. The exact time dependence of the excitations density in the system allows to identify the adiabatic and diabatic regions during the sweep and to study the m esoscopic fluctuations of the excitations. The effect of white noise is investigated, where the critical point transmutes into a non-hermitian ``degenerate region''. Besides an overall increase of the excitations during and at the end of the sweep, the most destructive effect of the noise is the decay of the state purity that is enhanced by the passage through the degenerate region.