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arXiv · 1103.2249

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

Jan Kunes·Vlastimil Krapek
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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.

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Jan Kunes, Vlastimil Krapek. 2011-03-11. Disproportionation and Metallization at Low-Spin to High-Spin Transition in Multiorbital Mott Systems. https://doi.org/10.1103/physrevlett.106.256401

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