Critical Fidelity
arXiv:cond-mat/0608555 · doi:10.1103/PhysRevLett.97.256404
Abstract
Using a Wigner Lorentzian Random Matrix ensemble, we study the fidelity, , of systems at the Anderson metal-insulator transition, subject to small perturbations that preserve the criticality. We find that there are three decay regimes as perturbation strength increases: the first two are associated with a gaussian and an exponential decay respectively and can be described using Linear Response Theory. For stronger perturbations decays algebraically as , where is the correlation dimension of the critical eigenstates.
4 pages, 3 figures. Revised and published in Phys. Rev. Lett