Fermi surface and pseudogap of electron-doped cuprate superconductors: Numerical study of thet−t′−Jmodel

Abstract

Spectral functions are evaluated numerically within the $t\text{\ensuremath{-}}{t}^{\ensuremath{'}}\text{\ensuremath{-}}J$ model as relevant for electron-doped cuprates. The Fermi surface develops from a pocketlike into a large one with doping. The corresponding pseudogap in the nodal direction is well resolved at low doping and vanishes at intermediate doping. Its presence is strongly temperature dependent and thus connected to longer-range antiferromagnetic correlations. Features including a double effective band and optical conductivity are consistent with experiments on electron-doped cuprates without invoking the closing of the Mott-Hubbard gap.