Doping evolution of the electronic structure in the single-layer cuprates Bi${}_2$Sr${}_{2-x}$La${}_x$CuO${}_{6+\hat{I}´}$: Comparison with other single-layer cuprates

Abstract

We have performed angle-resolved photoemission and core-level x-ray photoemission studies of the single-layer cuprate Bi${}_2$Sr${}_{2-x}$La${}_x$CuO${}_{6+\hat{I}´}$ (Bi2201) and revealed the doping evolution of the electronic structure from the lightly-doped to optimally-doped regions. We have observed the formation of the dispersive quasi-particle band, evolution of the Fermi ``arc'' into the Fermi surface and the shift of the chemical potential with hole doping as in other cuprates. The doping evolution in Bi2201 is similar to that in Ca${}_{2-x}$Na${}_x$CuO${}_2$Cl${}_2$ (Na-CCOC), where a rapid chemical potential shift toward the lower Hubbard band of the parent insulator has been observed, but is quite different from that in La${}_{2-x}$Sr${}_x$CuO${}_4$ (LSCO), where the chemical potential does not shift, yet the dispersive band and the Fermi arc/surface are formed around the Fermi level already in the lightly-doped region. The (underlying) Fermi surface shape and band dispersions are quantitatively analyzed using tight-binding fit, and the deduced next-nearest-neighbor hopping integral $t^{\prime }$ also confirm the similarity to Na-CCOC and the difference from LSCO.