Exotic Mott phases of the extended t--J model on the checkerboard lattice at commensurate densities
| dc.creator | Poilblanc, Didier | |
| dc.date | 2007-05-29 | |
| dc.date.accessioned | 2026-07-07T09:34:07Z | |
| dc.date.available | 2026-07-07T09:34:07Z | |
| dc.description | Coulomb repulsion between electrons moving on a frustrated lattice can give rise, at simple commensurate electronic densities, to exotic insulating phases of matter. Such a phenomenon is illustrated using an extended t--J model on a planar pyrochlore lattice for which the work on the quarter-filled case [cond-mat/0702367] is complemented and extended to 1/8- and 3/8-fillings. The location of the metal-insulator transition as a function of the Coulomb repulsion is shown to depend strongly on the sign of the hopping. Quite generally, the metal-insulator transition is characterized by lattice symmetry breaking but the nature of the insulating Mott state is more complex than a simple Charge Density Wave. Indeed, in the limit of large Coulomb repulsion, the physics can be described in the framework of (extended) quantum fully-packed loop or dimer models carrying extra spin degrees of freedom. Various diagonal and off-diagonal plaquette correlation functions are computed and the low-energy spectra are analyzed in details in order to characterize the nature of the insulating phases. We provide evidence that, as for an electronic density of n=1/2 (quarter-filling), the system at $n=1/4$ or $n=3/4$ exhibits also plaquette order by forming a (lattice rotationally-invariant) Resonating-Singlet-Pair Crystal, although with a quadrupling of the lattice unit cell (instead of a doubling for $n=1/2$) and a 4-fold degenerate ground state. Interestingly, qualitative differences with the bosonic analog (e.g. known to exhibit columnar order at n=1/4) emphasize the important role of the spin degrees of freedom in e.g. stabilizing plaquette phases w.r.t. rotational symmetry-breaking phases. | |
| dc.description | 7 pages, 7 figures Follow-up of cond-mat/0702367 | |
| dc.identifier | https://arxiv.org/abs/0705.4198 | |
| dc.identifier | http://arxiv.org/abs/0705.4198 | |
| dc.identifier | Phys. Rev. B 76, 115104 (2007) | |
| dc.identifier | doi:10.1103/PhysRevB.76.115104 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/159375 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.subject | Superconductivity | |
| dc.title | Exotic Mott phases of the extended t--J model on the checkerboard lattice at commensurate densities | |
| dc.type | text |