Multi-orbital kinetic effects on charge ordering of frustrated electrons on the triangular lattice

C. Février (1) , Simone Fratini (1) , A. Ralko (1)

1 NEEL - TMC - Théorie de la Matière Condensée

The role of the multi-orbital effects on the emergence of frustrated electronic orders on the triangular lattice at half-filling is investigated through an extended spinless fermion Hubbard model. By using two complementary approaches, unrestricted Hartree-Fock and exact diagonalizations, we unravel a very rich phase diagram controlled by the strength of both local and off-site Coulomb interactions and by the inter-orbital hopping anisotropy ratio t /t. Three robust unconventional electronic phases: a pinball liquid, an inverse pinball liquid and a large unit cell √ 12 × √ 12 droplet phase, are found to be generic in the triangular geometry, being controlled by the band structure parameters. The latter are also stabilized in the isotropic limit of our microscopic model, which recovers the standard SU(2) spinful extended single-band Hubbard model.

Domaines: Electrons fortement corrélés [cond-mat.str-el]

C. Février, Simone Fratini, A. Ralko. Multi-orbital kinetic effects on charge ordering of frustrated electrons on the triangular lattice. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2015, 91 (24), pp.245111. ⟨10.1103/PhysRevB.91.245111⟩. ⟨hal-01219133⟩