Phase diagram of the Hubbard chain with two atoms per cell
Abstract
We obtain the quantum phase diagram of the Hubbard chain with alternating on-site energy at half filling. The model is relevant for the ferroelectric perovskites and organic mixed-stack donor-acceptor crystals. For any values of the parameters, the band insulator is separated from the Mott insulator by a dimer phase. The boundaries are determined accurately by crossing of excited levels with particular discrete symmetries. We show that these crossings coincide with jumps of charge and spin Berry phases with a clear geometrical meaning.
- Publication:
-
Physical Review B
- Pub Date:
- September 2001
- DOI:
- 10.1103/PhysRevB.64.121105
- arXiv:
- arXiv:cond-mat/0107222
- Bibcode:
- 2001PhRvB..64l1105T
- Keywords:
-
- 71.30.+h;
- 71.10.Hf;
- 71.10.Pm;
- 77.80.-e;
- Metal-insulator transitions and other electronic transitions;
- Non-Fermi-liquid ground states electron phase diagrams and phase transitions in model systems;
- Fermions in reduced dimensions;
- Ferroelectricity and antiferroelectricity;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 5 pages including 2 figures To be published in Phys. Rev. B (Rapid Communications)