Possible exotic phases in the one-dimensional extended Hubbard model
Files
First author draft
Date
1999-02-15
Authors
Clay, R. Torsen
Sandvik, Anders W.
Campbell, David K.
Version
First author draft
OA Version
Citation
RT Clay, AW Sandvik, DK Campbell. 1999. "Possible exotic phases in the one-dimensional extended Hubbard model." PHYSICAL REVIEW B, Volume 59, Issue 7, pp. 4665 - 4679 (15). https://doi.org/10.1103/PhysRevB.59.4665
Abstract
We investigate numerically the ground state phase diagram of the one-dimensional extended Hubbard model, including an on-site interaction U and a nearest-neighbor interaction V. We focus on the ground state phases of the model in the V≫U region, where previous studies have suggested the possibility of dominant superconducting pairing fluctuations before the system phase separates at a critical value V=V𝘱𝒔. Using quantum Monte Carlo methods on lattices much larger than in previous Lanczös diagonalization studies, we determine the boundary of phase separation, the Luttinger-liquid correlation exponent Kρ, and other correlation functions in this region. We find that phase separation occurs for V significantly smaller than previously reported. In addition, for negative U, we find that a uniform state reenters from phase separation as the electron density is increased towards half filling. For V<V𝘱𝑠, our results show that superconducting fluctuations are not dominant. The system behaves asymptotically as a Luttinger liquid with Kρ<1, but we also find strong low-energy (but gapped) charge-density fluctuations at a momentum not expected for a standard Luttinger liquid.