Nonlinear Sciences – Chaotic Dynamics
Scientific paper
2006-01-16
Nonlinear Sciences
Chaotic Dynamics
Scientific paper
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 the 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 results of Prosen and Znidaric are extended by a supersymmetry calculation to arbitrary strengths of the perturbation for the case of an unperturbed Hamiltonian taken from the Gaussian orthogonal ensemble and a purely unitary antisymmetric perturbation. It is found that for the exact calculation the freeze of fidelity is only slightly reduced as compared to the linear-response approximation. This may have important consequences for the design of quantum computers.
No associations
LandOfFree
Fidelity freeze for a random matrix model with off--diagonal perturbation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Fidelity freeze for a random matrix model with off--diagonal perturbation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fidelity freeze for a random matrix model with off--diagonal perturbation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-523875