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Physical review. B, Condensed matter

Nonperturbative results for attractive Hubbard pairings in triangular lattices

Luis Antonio Pérez, Oracio Navarro, C. Wang

Published Jun 15, 1996• 17 citations
Publisher

Abstract

The electron pairing problem is studied by means of the extended Hubbard Hamiltonian. The original many-body problem is mapped onto a tight-binding one in a higher dimensional space, where the problem can be solved in an exact way. In a triangular lattice, the effects of the frustration of antibonding states on the electronic correlation are analyzed in detail. It is found that the hole pairing is always stronger than the electron case, in contrast with the bipartite lattices, where there is a complete symmetry between electron and hole pairings. The ground state of two holes, when the attractive nearest-neighbor interaction is dominant, is surprisingly triplet and its wave function has directional nodes. A pairing phase diagram for holes in triangular lattices is also presented. \textcopyright{} 1996 The American Physical Society.

DOI
10.1103/physrevb.53.15389

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The electron pairing problem is studied by means of the extended Hubbard Hamiltonian. The original many-body problem is mapped onto a tight-binding one in a higher dimensional space, where the problem can be solved in an exact way. In a triangular lattice, the effects of the frustration of antibonding states on the electronic correlation are analyzed in detail. It is found that the hole pairing is always stronger than the electron case, in contrast with the bipartite lattices, where there is a complete symmetry between electron and hole pairings. The ground state of two holes, when the attractive nearest-neighbor interaction is dominant, is surprisingly triplet and its wave function has directional nodes. A pairing phase diagram for holes in triangular lattices is also presented. \textcopyright{} 1996 The American Physical Society.
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