Partial ferromagnetism in a two-band Hubbard model with semimetallic bands: Numerical evidences and a rigorous result

Koichi Kusakabe, Shinji Watanabe, Yoshio Kuramoto

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Role of the double exchange for appearance of partial ferromagnetism in a semimetal is explored for a semimetallic two-band Hubbard model in one-dimension. In a strong coupling limit, a ferromagnetic exchange interaction between two neighboring triplet excitons becomes dominant compared with anti-ferromagnetic couplings and a partial spin polarization is shown to appear. Exact evaluation of magnetization is possible for the partially ferromagnetic ground state in this limit. Obtained phase diagram has a doping dependence similar to our DMRG results for finite interactions. The ferromagnetism is favored in semimetallic systems by the interplay of the intra-orbital Coulomb repulsion and the inter-orbital Hund-rule coupling.

Original languageEnglish
Pages (from-to)311-313
Number of pages3
Journaljournal of the physical society of japan
Volume71
Issue numberSUPPL.
Publication statusPublished - 2002 Dec 1

Keywords

  • DMRG
  • Exact proof
  • Partial ferromagnetism
  • Semimetal
  • Two-band hubbard model

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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