Analysis of the first electron-removal states of using polarization dependent angle-resolved photoelectron spectroscopy

: The first electron-removal states of the layered cuprate Ba 2 Cu 3 O 4 Cl 2 were measured using angle-resolved photoelectron spectroscopy. The symmetry and energy-momentum relations of the lowest-lying states were determined and interpreted in terms of the motion of a single hole in the two different planar Cu-O subsystems of the Cu 3 O 4 plane. One subsystem is antiferromagnetic as in the undoped parent compounds of the high-temperature superconductors and the other is paramagnetic and corresponds to the strongly overdoped case. The data are compared to theoretical results on hole dynamics in two-dimensional antiferromagnetic or paramagnetic spin backgrounds. The lineshape, symmetry and dispersion of the first electron-removal states of Ba 2 Cu 3 O 4 Cl 2 can be described in terms of Zhang-Rice singlets within a single band model. The photohole lifetime in the paramagnetic subsystem of the Cu 3 O 4 plane is much smaller than with an antiferromagnetic spin background.