Abstract
The relationship between charged and spin-excitation gaps of the half-filled Hubbard model, the symmetric periodic Anderson model, and the Kondo lattice model is considered for a general d-dimensional bipartite lattice. In a previous paper [G. S. Tian, Phys. Rev. B 58, 7612 (1998)], it was shown that the quasiparticle gaps of these models at half filling are always larger than their spin excitation gaps. In the present paper, we establish a theorem, which states that the charged gap is also greater than the corresponding spin gap in these models. This conclusion, which has been reached previously for one-dimensional systems based on variational and the density-matrix renormalization-group numerical calculations, is thus put on a rigorous and more general footing.
Original language | English |
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Pages (from-to) | 11336-11344 |
Number of pages | 9 |
Journal | Physical Review B |
Volume | 60 |
Issue number | 16 |
DOIs | |
Publication status | Published - 1999 |
Scopus Subject Areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics