Electronic Theory for the Transition from Fermi-Liquid to Non-Fermi-Liquid Behavior in High-T$_{c}$ Superconductors

摘要

We analyze the breakdown of Fermi-liquid behavior within the 2D Hubbard modelas function of doping using our recently developed numerical method for theself consistent summation of bubble and ladder diagrams. For larger dopingconcentrations the system behaves like a conventional Fermi-liquid and forintermediate doping similar to a marginal Fermi-liquid. However, for smallerdoping pronounced deviations from both pictures occur which are due to theincreasing importance of the short range antiferromagnetic spin fluctuations.This is closely related to the experimental observed shadow states in thenormal state of high-$T_c$ superconductors. Furthermore, we discuss theimplications of our results for transport experiments.