SYSTEMATIC 1/S STUDY OF THE 2-DIMENSIONAL HUBBARD-MODEL AT HALF-FILLING

Article

关键词: QUANTUM HEISENBERG-ANTIFERROMAGNET;    HIGH-TEMPERATURE SUPERCONDUCTIVITY;    SQUARE-LATTICE;    SPIN FLUCTUATIONS;    SINGLE HOLE;    EXCITATIONS;    MOTION;    INSTABILITIES;   

DOI  :  10.1103/PhysRevB.50.6238

来源: SCIE

【 摘 要 】

The two-dimensional Hubbard model is extended by placing 2S orbitals at each lattice site and studied in a systematic 1/S expansion. The 1/S results for the magnetic susceptibilitity and the spectra of spin-wave excitations at half-filling are consistent with the large S calculations for the Heisenberg antiferromagnet. The 1/S corrections to the fermionic spectrum lift the degeneracy along the edge of the magnetic Brillouin zone yielding minima at (+/- pi/2, +/- pi/2). Relation to previous papers on the subject is discussed.

【 授权许可】

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