Charge ordering and magnetism in quarter-filled Hubbard-Holstein model

Abstract

We study a two-dimensional Hubbard-Holstein model with phonons treated in the adiabatic limit. A Hartree-Fock decomposition is employed for the Hubbard term. A range of electronic densities are discussed with special emphasis on the quarter-filling ($n=0.5$). We argue that the quarter-filled system is relevant for the electronic properties observed at the interface between LaAlO${}_3$ and SrTiO${}_3$, where half-electron per unit cell is transferred to the TiO${}_2$ layer as a consequence of the polar discontinuity at the interface. In addition to presenting the overall phase diagrams, we identify an interesting charge-ordered antiferromagnetic phase for $n=0.5$, which was also reported recently in the ab-initio study of the LaAlO${}_3$-SrTiO${}_3$ interface.

6 pages, 5 figures

References in corpus (5)

• Magnetic effects at the interface between nonmagnetic oxides
• Two-dimensional Hubbard-Holstein bipolaron
• Electronic structure induced reconstruction and magnetic ordering at the LaAlO${}_3|$SrTiO${}_3$ interface
• Phase diagram of the one dimensional Hubbard-Holstein Model at 1/2 and 1/4 filling
• Interface controlled electronic charge inhomogeneities in correlated heterostructures

Cited by in corpus (2)

• Polarity-induced oxygen vacancies at LaAlO3|SrTiO3 interfaces
• Competition between antiferromagnetic and charge order in the Hubbard-Holstein model