title: Stability of the Zhang-Rice Singlet with Doping in Lanthanum Strontium Copper Oxide Across the Superconducting Dome and Above.
abstract: The spin character of the states at the top of the valence band in doped La(2-x)Sr(x)CuO(4) (x=0.03, 0.07, 0.15, 0.22, and 0.30) has been investigated using spin-polarized resonant photoemission. A clear Zhang-Rice singlet (ZRS) is observed at all doping levels. Its stability and polarization are preserved as a function of doping, suggesting that the concept of the ZRS can be used across a wide doping range and up to the metallic nonsuperconducting overdoped regime. The results are significant for theoretical models that use the ZRS approximation and for the understanding of the peculiar interplay between the ZRS and the remaining localized spins.
authors.affiliation: European Synchrotron Radiation Facility, CS 40220, F-38043 Grenoble, Cedex 9, France.
authors.forename: N B
authors.initials: NB
authors.lastname: Brookes
authors.affiliation: European Synchrotron Radiation Facility, CS 40220, F-38043 Grenoble, Cedex 9, France.|Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Ghiringhelli
authors.affiliation: University Joseph Fourier, UGA, PhITEM, BP 53, F-38041 Grenoble, Cedex 9, France.
authors.forename: A-M
authors.initials: AM
authors.lastname: Charvet
authors.affiliation: Department of Physics, University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Fujimori
authors.affiliation: Department of Physics, University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kakeshita
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Eisaki
authors.affiliation: Department of Physics, University of Tokyo, Tokyo 113-0033, Japan.|National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Uchida
authors.affiliation: Department of Complexity Science and Engineering, University of Tokyo, Chiba 277-8561, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mizokawa