Phys. Rev. B 62, 15047–15055 (2000)Ferromagnetic polarons in manganitesReceived 19 July 1999; revised 8 June 2000; published in the issue dated 1 December 2000 Using the Lanczos method in linear chains we study the double exchange model in the low concentration limit, including an antiferromagnetic super-exchange K. In the strong-coupling limit we find that the ground state contains ferromagnetic polarons whose length is very sensitive to the value of K/t. We investigate the dispersion relation, the trapping by impurities, and the interaction between these polarons. As the overlap between polarons increases, by decreasing K/t, the effective interaction between them changes from antiferromagnetic to ferromagnetic. The scaling to the thermodynamic limit suggests an attractive interaction in the strong-coupling regime (Jh>t) and no binding in the weak limit (Jh≃t). © 2000 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevB.62.15047
DOI:
10.1103/PhysRevB.62.15047
PACS:
75.50.Cc, 71.38.+i
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