Abstract

A general constructive procedure is presented for analyzing magnetic instabilities in two-dimensional materials, in terms of (predominantly) double nesting, and applied to Hartree-Fock plus random-phase approximation (HF+RPA) and Gutzwiller approximation plus RPA calculations of the Hubbard model. Applied to the cuprates, it is found that competing magnetic interactions are present only for hole doping, between half filling and the Van Hove singularity. While HF+RPA instabilities are present at all dopings (for sufficiently large Hubbard U), in a Gutzwiller approximation they are restricted to a doping range close to the range of relevance for the physical cuprates. The same model would hold for charge instabilities, except that the interaction is more likely to be q dependent.

Notes

Originally published in Physical Review B v.81 (2010): 014509. DOI: 10.1103/PhysRevB.81.014509

Keywords

magnetic instabilities, Gutzwiller approximation, Hartree-Fock plus random-phase approximation, Van Hove singularity, cuprates

Subject Categories

Hubbard model

Disciplines

Physics

Publisher

American Physical Society

Publication Date

1-13-2010

Rights Information

Copyright 2010 American Physical Society.

Rights Holder

American Physical Society

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