New auxiliary particle method for the Hubbard, t-J and Heisenberg models

D. Vacaru, Stewart Barnes

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Abstract

A new bond auxiliary particle method for the Hubbard, t-J and Heisenberg Hamiltonians is presented. First, the one-dimensional (ID) Heisenberg Hamiltonian is studied as a test case. The exact ground state is approached rapidly via perturbation theory. At the level of second-order perturbation theory, the ground state energy is accurate within a few per cent, while in the 15th order it is accurate to five figures. Without any renormalization, the spin velocity is given with 10% accuracy, and the spectrum is correctly gapless. The degeneracy is also correct, giving a Wilson ratio R = 2. The method is used to calculate analytically the full Green's function for a single hole in a half-filled (one electron per site) t-J model.

Original languageEnglish (US)
Pages (from-to)719-728
Number of pages10
JournalJournal of Physics Condensed Matter
Volume6
Issue number3
DOIs
StatePublished - 1994

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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