Phase diagram of the half-filled extended Hubbard model in two dimensions

Journal Article · Sun Jun 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.15364· OSTI ID:530193

Chattopadhyay, B; Gaitonde, D M ^[1]

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1. The Mehta Research Institute of Mathematics and Mathematical Physics, 10 Kasturba Gandhi Marg, Allahabad 211002 (India)

We consider an extended Hubbard model of interacting fermions on a lattice. The fermion kinetic energy corresponds to a tight-binding Hamiltonian with nearest-neighbor ({minus}t) and next-nearest-neighbor (t{sup {prime}}) hopping matrix elements. In addition to the on-site Hubbard interaction (U) we also consider a nearest-neighbor repulsion (V). We obtain the zero-temperature phase diagram of our model within the Hartree-Fock approximation. We consider ground states having charge- and spin-density-wave ordering as well as states with orbital antiferromagnetism or spin nematic order. The latter two states correspond to particle-hole binding with d{sub x{sup 2}{minus}y{sup 2}} symmetry in the charge and spin channels, respectively. For t{sup {prime}}=0, only the charge-density-wave and spin-density-wave states are energetically stable. For nonzero t{sup {prime}}, we find that orbital antiferromagnetism (or spin nematic) order is stable over a finite portion of the phase diagram at weak coupling. This region of stability is seen to grow with increasing values of t{sup {prime}}. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 530193
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 23 Vol. 55; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANTIFERROMAGNETISM
CHARGE DENSITY
ELECTRONIC STRUCTURE
FERMIONS
GROUND STATES
HARTREE-FOCK METHOD
HUBBARD MODEL
PHASE DIAGRAMS
SPIN WAVES