Low-energy electronic structure of the high-Tccuprates La2−xSrxCuO4studied by angle-resolved photoemission spectroscopy

We have performed a systematic angle-resolved photoemission spectroscopy (ARPES) study of the high- T c cuprates La 2− x Sr x CuO 4 , ranging from the underdoped insulator to the superconductor to the overdoped metal. We have revealed a systematic doping evolution of the band dispersions and (underlying) Fermi surfaces, pseudogap and quasi-particle features under the influence of strong electron–electron interaction and electron–phonon interaction. The unusual transport and thermodynamic properties are explained by taking into account the pseudogap opening and the Fermi arc formation, due to which the carrier number decreases as the doped hole concentration decreases.