Influence of doping on the electronic structure of (La, Sr)2CuO4

摘要

High statistics, (> 4 x 10(sup 8) counts), room temperature measurements of the electron-positron momentum density of La(sub 2-x)Sr(sub x)CuO(sub 4) have been performed for samples with Sr concentrations of x - 0.0, 0.1, 0.13 and 0.2. These spectra have been analyzed in conjunction with theoretical calculations of the electron-positron momentum density. The metallic samples show features consistent with the presence of a Fermi surface, but its evolution with increasing Sr concentration does not follow the predictions of band theory. These results may indicate the effects of electron-electron correlation on the electron momentum distribution in the Cu-O plane.