Theoretical study of insulating mechanism in multiorbital Hubbard models with a large spin-orbit coupling

Slater versus Mott scenario in Sr2 IrO4

Hiroshi Watanabe, Tomonori Shirakawa, Seiji Yunoki

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

To examine the insulating mechanism of 5d transition metal oxide Sr2IrO4, we study the ground state properties of a three-orbital Hubbard model with a large relativistic spin-orbit coupling on a square lattice. Using a variational Monte Carlo method, we find that the insulating state appearing in the ground state phase diagram for one hole per site varies from a weakly correlated to a strongly correlated antiferromagnetic (AF) state with increasing Coulomb interactions. This crossover is characterized by the different energy gain mechanisms of the AF insulating state, i.e., from an interaction-energy-driven Slater-type insulator to a band-energy-driven Mott-type insulator with increasing Coulomb interactions. Our calculations reveal that Sr2IrO4 is a "moderately correlated" AF insulator located in the intermediate coupling region between a Slater-type and a Mott-type insulator.

Original languageEnglish
Article number165115
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume89
Issue number16
DOIs
Publication statusPublished - 2014 Apr 14
Externally publishedYes

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Hubbard model
Coulomb interactions
Ground state
Orbits
insulators
orbits
Band structure
Oxides
Phase diagrams
Transition metals
Monte Carlo methods
ground state
interactions
energy bands
metal oxides
Monte Carlo method
crossovers
transition metals
phase diagrams
orbitals

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Theoretical study of insulating mechanism in multiorbital Hubbard models with a large spin-orbit coupling : Slater versus Mott scenario in Sr2 IrO4. / Watanabe, Hiroshi; Shirakawa, Tomonori; Yunoki, Seiji.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 89, No. 16, 165115, 14.04.2014.

Research output: Contribution to journalArticle

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