Charge-order transition in the extended Hubbard model on a two-leg ladder
Abstract
We investigate the charge-order transition at zero temperature in a two-leg Hubbard ladder with additional nearest-neighbor Coulomb repulsion V using the density matrix renormalization group technique. We consider electron densities between quarter and half filling. For quarter filling and U=8t, we find evidence for a continuous phase transition between a homogeneous state at small V and a broken-symmetry state with ``checkerboard'' [wave vector Q=(π,π)] charge order at large V. This transition to a checkerboard charge-ordered state remains present at all larger fillings, but becomes discontinuous at sufficiently large filling. We discuss the influence of U/t on the transition and estimate the position of the tricritical points.
- Publication:
-
Physical Review B
- Pub Date:
- September 1999
- DOI:
- 10.1103/PhysRevB.60.R8417
- arXiv:
- arXiv:cond-mat/9906101
- Bibcode:
- 1999PhRvB..60.8417V
- Keywords:
-
- 71.10.Fd;
- 71.10.Pm;
- 71.27.+a;
- Lattice fermion models;
- Fermions in reduced dimensions;
- Strongly correlated electron systems;
- heavy fermions;
- Condensed Matter
- E-Print:
- 4 pages, 5 figs, minor changes, accepted for publication in PRB RC