Energy scales and quasiparticle properties in an extended Hubbard model for HTC

By means of a strong-coupling approach, developed in previous works, we study the quasiparticle properties in an extended Hubbard model in presence of critical charge fluctuations near a stripe-quantum critical-point. We show that the quasiparticle dispersion has a kink along the diagonal Brillouin zone at the energy of the order 50 meV, for realistic values of the parameters. The energy and momentum distribution curves (EDC, MDC) along the diagonal are also analyzed. The results for the EDC derived quasiparticle width reveals an anomalous drop in the low-energy scattering rate at the same energy of the kink. This drop corresponds to a new energy scale in the system that reflects the interaction between the quasiparticles and the critical charge fluctuations. The results offer a possible interpretation of the ARPES and photoemission experiments on Bi2212.Received: 17 November 2003, Published online: 19 February 2004PACS: 71.10.Fd Lattice fermion models (Hubbard model, etc.) - 71.10.Hf Non-Fermi-liquid ground states, electron phase diagrams and phase transitions in model systems