Phase diagram of the half-filled extended Hubbard model in two dimensions
- 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, Vol. 55, Issue 23; Other Information: PBD: Jun 1997
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dynamic susceptibility and photoemission in the {ital t}-{ital t}{prime}-{ital J} model
Hole motion in the t - J and Hubbard models: Effect of a next-nearest-neighbor hopping