Doping Dependence of an [Formula presented]-Type Cuprate Superconductor Investigated by Angle-Resolved Photoemission Spectroscopy

We present an angle-resolved photoemission doping dependence study of the [Formula presented]-type cuprate superconductor [Formula presented], from the half-filled Mott insulator to the [Formula presented] superconductor. In [Formula presented], we reveal the charge-transfer band for the first time. As electrons are doped into the system, this feature’s intensity decreases with the concomitant formation of near- [Formula presented] spectral weight. At low doping, the Fermi surface is an electron-pocket (with volume [Formula presented]) centered at [Formula presented]. Further doping leads to the creation of a new holelike Fermi surface (volume [Formula presented]) centered at [Formula presented]. These findings shed light on the Mott gap, its doping evolution, as well as the anomalous transport properties of the [Formula presented]-type cuprates.