Excitation spectra in doped high-Tc cuprates Original Research Article

The spectral function of high-temperature superconductors in the underdoped and lightly doped regions is investigated theoretically. We take into account the tilting of CuO octahedra which induces the staggered transfer integral between px,y orbitals and Cu t2g orbitals. We show that the spectral weight shows a peak at around (π/2, π/2) for light doping and extends around this point forming an arc with increasing carrier density continuously to be the spectra in the optimally doped region. This behavior well explains ARPES spectra called Fermi arc.