Breakdown of the Luttinger sum rule at the Mott-Hubbard transition in the one-dimensional - Hubbard modelC. Gros1, K. Hamacher2 and W. Wenzel3
1 Fakultät 7, Theoretische Physik, University of the Saarland 66041 Saarbrücken, Germany
2 Department of Physics, University of California, San Diego 9500 Gilman Drive, MC0374, La Jolla, CA 92093, USA
3 Forschungszentrum Karlsruhe, Institut für Nanotechnologie Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
received 21 September 2004; accepted in final form 8 December 2004
published online 14 January 2005
We investigate the momentum distribution function near the Mott-Hubbard transition in the one-dimensional t1- t2 Hubbard model (the zigzag Hubbard chain) with the density matrix renormalization group technique. We show that for strong interactions the Mott-Hubbard transition occurs between the metallic phase and an insulating dimerized phase with incommensurate spin excitations, suggesting a decoupling of magnetic and charge excitations not present in weak coupling. We illustrate the signatures for the Mott-Hubbard transition and the commensurate-incommensurate transition in the insulating spin-gaped state in their respective ground-state momentum distribution functions.
75.10.Jm - Quantized spin models.
75.40.Mg - Numerical simulation studies.
© EDP Sciences 2005