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arXiv · 1603.01800

Spin-Orbital Entangled Excitonic Insulators in $(t_{2g})^4$ Correlated Electron Systems

Toshihiro Sato·Tomonori Shirakawa·Seiji Yunoki
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Abstract

We employ the multi-orbital dynamical mean-field theory to examine the ground state of a three-orbital Hubbard model with a relativistic spin-orbit coupling (SOC) at four electrons per site. We demonstrate that the interplay between the strong electron correlations and the SOC induces a Van Vleck-type nonmagnetic insulator and its magnetic exciton condensation. We also find in the moderate electron correlation regime that the SOC induces another type of a nonmagnetic excitonic insulator, in addition to a relativistic band insulator. The characteristic features among these insulators are manifested in the momentum resolved single-particle excitations, thus accessible by angle-resolved photoemission spectroscopy experiments.

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Toshihiro Sato, Tomonori Shirakawa, Seiji Yunoki. 2016-03-06. Spin-Orbital Entangled Excitonic Insulators in $(t_{2g})^4$ Correlated Electron Systems. https://doi.org/10.1103/physrevb.99.075117

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