Nonperturbative results for attractive Hubbard pairings in triangular lattices

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.15389· OSTI ID:284718

Perez, L A; Navarro, O; Wang, C ^[1]

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1. Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-360, 04510, Distrito Federal (Mexico)

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. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 284718
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 23 Vol. 53; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CORRELATION FUNCTIONS
GROUND STATES
HUBBARD MODEL
MANY-BODY PROBLEM
PAIRING INTERACTIONS
PHASE DIAGRAMS
TIGHT BINDING APPROXIMATION
TRIANGULAR LATTICES
WAVE FUNCTIONS