Photoemission Study of La8-xSrxCu8O20: Impact of the Charge and Spin Density Waves on the Electronic Structure

Abstract

We report a photoemission study of La 8- x Sr x Cu 8 O 20 which shows antiferromagnetic (AFM), weakly ferromagnetic (WFM), and paramagnetic (PM) phases. All the samples in the AFM, WFM or PM phases are found to have a sharp Fermi edge with finite density of states at the Fermi level ( E F ), indicating the metallic nature of the samples at different doping and temperatures studied. In the WFM and AFM phases, the spectral weight near the E F (up to ∼-200 meV) is partially suppressed. In the valence band spectra, the Cu 3 d and O 2 p derived states around ∼-5 and ∼-2.5 eV show different spectral weights in different magnetic phases. The observed changes in the electronic structure can be due to formation of the charge and/or spin density waves causing the anomalies in the electronic and magnetic transport properties of this system.