Breit-Wigner Width and Inverse Participation Ratio in Finite Interacting Fermi Systems
Breit-Wigner Width and Inverse Participation Ratio in Finite Interacting Fermi Systems
For many-body Fermi systems we determine the dependence of the Breit-Wigner width $\ensuremath{\gamma}$ and inverse participation ratio $\ensuremath{\xi}$ on interaction strength $U\ensuremath{\ge}{U}_{c}$ and energy excitation $\ensuremath{\delta}E\ensuremath{\ge}\ensuremath{\delta}{E}_{\mathrm{ch}}$ when a crossover from Poisson to Wigner-Dyson $P(s)$ statistics takes place. At $U\ensuremath{\ge}{U}_{c}$ the eigenstates are composed of a large number of noninteracting states …