Spin Bags, Polarons and Impurity Potentials in LA2-xSRxCUO4 from First Principles.

Anisimov V. I., Korotin M. A., Zaanen J., Andersen O. K.

Yekaterinburg Met Phys Inst Yekaterinburg Gsp170 Ussr
Univ Oulu Dept Theoret Phys Sf-90100 Oulu 10 Finland
At&t Bell Labs Murray Hill Nj 07974
Max Planck Inst Festkorperforsch W-7000 Stuttgart 80 Germany

A full-potential version of a recently proposed generalization of the local-density method (LDA + U) is used to study the influence of impurities, lattice, and magnetic relaxation in La2-xSrxCuO4. The carriers form mean-field analogs of Zhang-Rice singlets, which are only slightly affected by impurity and in-plane lattice relaxation effects. On the other hand, an "anti-Jahn-Teller" polaron, characterized by a 0.26 angstrom shorter Cu to apical-oxygen bond length and triplet spin, is nearly stable. Although the impurity potentials are similar, the self-localization effects are much stronger in La2-xSrxNiO4.

Physical Review Letters, 68 345-348, 1992.

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