Disproportionation and Metallization at Low-Spin to High-Spin Transition in Multiorbital Mott Systems

Abstract

We study the thermally driven spin state transition in a two-orbital Hubbard model with crystal field splitting, which provides a minimal description of the physics of LaCoO3. We employ the dynamical mean-field theory with quantum Monte-Carlo impurity solver. At intermediate temperatures we find a spin disproportionated phase characterized by checkerboard order of sites with small and large spin moments. The high temperature transition from the disproportionated to a homogeneous phase is accompanied by vanishing of the charge gap. With the increasing crystal-field splitting the temperature range of the disproportionated phase shrinks and eventually disappears completely.

4+ pages, 4 figures

References in corpus (3)

• The ALPS project release 1.3: open source software for strongly correlated systems
• High-spin to low-spin and orbital polarization transitions in multiorbital Mott systems
• Pressure-Driven Metal-Insulator Transition in Hematite from Dynamical Mean-Field Theory

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