Quasiparticle band in the frustrated t-t'-J model.

Abstract

We investigate the influence of frustration on the quasiparticle dispersion in the t-J and t-${\mathit{t}}^{\ensuremath{'}}$-J models using the linear spin-wave theory and self-consistent Born approximation. The next-neighbor antiferromagnetic interactions, simulating the effect of doping within ${\mathrm{CuO}}_{2}$ planes of high-${\mathit{T}}_{\mathit{c}}$ superconductors, lead to a drastic reduction of the quasiparticle bandwidth with the increasing frustration in a wide range of t, ${\mathit{t}}^{\ensuremath{'}}$, and J parameters. The low-energy quasiparticle band (with the width only \ensuremath{\sim}0.3 eV) obtained for the realistic values of parameters and a very weak quasiparticle state at the (0,0) point in the Brillouin zone agree quite well with the flat band observed at the Fermi level in the angle-resolved photoemission experiments for ${\mathrm{Bi}}_{2}$${\mathrm{Sr}}_{2}$${\mathrm{CaCu}}_{2}$${\mathrm{O}}_{8+\mathrm{\ensuremath{\delta}}}$. \textcopyright{} 1996 The American Physical Society.