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arXiv · 0905.1389

Spin-state transition and phase separation in multi-orbital Hubbard model

Ryo Suzuki·Tsutomu Watanabe·Sumio Ishihara
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Abstract

We study spin-state transition and phase separation involving this transition based on the milti-orbital Hubbard model. Multiple spin states are realized by changing the energy separation between the two orbitals and the on-site Hund coupling. By utilizing the variational Monte-Carlo simulation, we analyze the electronic and magnetic structures in hole doped and undoped states. Electronic phase separation occurs between the low-spin band insulating state and the high-spin ferromagnetic metallic one. Difference of the band widths in the two orbitals is of prime importance for the spin-state transition and the phase separation.

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Ryo Suzuki, Tsutomu Watanabe, Sumio Ishihara. 2009-05-09. Spin-state transition and phase separation in multi-orbital Hubbard model. https://doi.org/10.1103/physrevb.80.054410

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