Abstract
The two-dimensional Hubbard model is extended by placing 2S orbitals at each lattice site and studied in a systematic 1/S expansion. The 1/S results for the magnetic susceptibility and the spectra of spin-wave excitations at half-filling are consistent with the large S calculations for the Heisenberg antiferromagnet. The 1/S corrections to the fermionic spectrum lift the degeneracy along the edge of the magnetic Brillouin zone yielding minima at (±π/2,±π/2). Relation to previous papers on the subject is discussed.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6238-6245 |
| Number of pages | 8 |
| Journal | Physical Review B |
| Volume | 50 |
| Issue number | 9 |
| DOIs | |
| State | Published - 1994 |