Pinball liquid phase from Hund's coupling in frustrated transition-metal oxides

Arnaud Ralko (1) , Jaime Merino (2) , Simone Fratini (1)

1 NEEL - TMC - Théorie de la Matière Condensée
2 UAM - Universidad Autónoma de Madrid

The interplay of non-local Coulomb repulsion and Hund's coupling in the d-orbital manifold in frustrated triangular lattices is analyzed by a multiband extended Hubbard model. We find a rich phase diagram with several competing phases, including a robust pinball liquid phase, which is an unconventional metal characterized by threefold charge order, bad metallic behavior and the emergence of high spin local moments. Our results naturally explain the anomalous charge-ordered metallic state observed in the triangular layered compound AgNiO2. The potential relevance to other triangular transition metal oxides is discussed.

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

Arnaud Ralko, Jaime Merino, Simone Fratini. Pinball liquid phase from Hund's coupling in frustrated transition-metal oxides. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2015, 91 (16), pp.165139. ⟨10.1103/PhysRevB.91.165139⟩. ⟨hal-01219131⟩