Correlation effects in a band ferromagnet: Spin-rotationally-symmetric study with self-energy and vertex corrections

Article

关键词: DYNAMIC SUSCEPTIBILITY;    HUBBARD-MODEL;    ITINERANT FERROMAGNETS;    ELECTRON CORRELATION;    MAGNETIC DYNAMICS;    WAVES;    LATTICES;    NICKEL;   

DOI  :  10.1103/PhysRevB.74.224437

来源: SCIE

【 摘 要 】

Quantum corrections to the transverse spin-fluctuation propagator are obtained by including self-energy and vertex corrections to first order within a spin-rotationally-symmetric inverse-degeneracy (1/N) expansion scheme which preserves the Goldstone mode order by order. A correlation-induced exchange-energy correction is shown to yield the dominant quantum reduction in the spin stiffness, providing a quantitative understanding of the ferromagnetic-state stability in terms of simple lattice-dependent features of energy-band dispersion. The quantum reduction factor U/W highlights the subtlety in the characteristic competition in a band ferromagnet between interaction U and bandwidth W.

【 授权许可】

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