Magnetic field effects in a correlated electron system with Spin-State degree of freedom - Implications for an excitonic insulator

Taro Tatsuno, Eriko Mizoguchi, Joji Nasu, Makoto Naka, Sumio Ishihara

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18 Citations (Scopus)


Magnetic field (H) effects on a correlated electron system with a spin-state degree of freedom are examined. The effective Hamiltonian derived from the two-orbital Hubbard model is analyzed by the mean-field approximation. Applying a magnetic field to the low-spin (LS) phase induces an excitonic insulating phase as well as a spin-state ordered phase where the LS and high-spin (HS) states are ordered alternately. When H is applied to the HS phase, a reentrant transition for the HS phase appears. A rich variety of the phase diagrams is attributed to the spin-state degree of freedom and their combinations in the wave function as well as in the real-space configuration. The present results provide a possible interpretation for the recent experimental observation of LaCoO3 under a strong magnetic field.

Original languageEnglish
Article number083706
JournalJournal of the Physical Society of Japan
Issue number8
Publication statusPublished - 2016 Aug 15
Externally publishedYes


ASJC Scopus subject areas

  • Physics and Astronomy(all)

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