### Abstract

Using the mean-field approximation, we study the k-space spin textures and local spin currents emerged in the spin-triplet excitonic insulator states of the two-band Hubbard model defined on the square and triangular lattices. We assume a noninteracting band structure with a direct band gap and introduce s-, p-, d-, and f-type cross-hopping integrals, i.e., the hopping of electrons between different orbitals on adjacent sites with four different symmetries. First, we calculate the ground-state phase diagrams in the parameter space of the band filling and interaction strengths, whereby we present the filling dependence of the amplitude and phase of the excitonic order parameters. Then, we demonstrate that the spin textures (or asymmetric band structures) are emerged in the Fermi surfaces by the excitonic symmetry breaking when particular phases of the order parameter are stabilized. Moreover, in the case of the p-type cross-hopping integrals, we.

Original language | English |
---|---|

Article number | 035119 |

Journal | Physical Review B |

Volume | 99 |

Issue number | 3 |

DOIs | |

Publication status | Published - 2019 Jan 10 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics

### Cite this

*Physical Review B*,

*99*(3), [035119]. https://doi.org/10.1103/PhysRevB.99.035119

**Spin texture and spin current in excitonic phases of the two-band Hubbard model.** / Nishida, Hisao; Miyakoshi, Shohei; Kaneko, Tatsuya; Sugimoto, Koudai; Ohta, Yukinori.

Research output: Contribution to journal › Article

*Physical Review B*, vol. 99, no. 3, 035119. https://doi.org/10.1103/PhysRevB.99.035119

}

TY - JOUR

T1 - Spin texture and spin current in excitonic phases of the two-band Hubbard model

AU - Nishida, Hisao

AU - Miyakoshi, Shohei

AU - Kaneko, Tatsuya

AU - Sugimoto, Koudai

AU - Ohta, Yukinori

PY - 2019/1/10

Y1 - 2019/1/10

N2 - Using the mean-field approximation, we study the k-space spin textures and local spin currents emerged in the spin-triplet excitonic insulator states of the two-band Hubbard model defined on the square and triangular lattices. We assume a noninteracting band structure with a direct band gap and introduce s-, p-, d-, and f-type cross-hopping integrals, i.e., the hopping of electrons between different orbitals on adjacent sites with four different symmetries. First, we calculate the ground-state phase diagrams in the parameter space of the band filling and interaction strengths, whereby we present the filling dependence of the amplitude and phase of the excitonic order parameters. Then, we demonstrate that the spin textures (or asymmetric band structures) are emerged in the Fermi surfaces by the excitonic symmetry breaking when particular phases of the order parameter are stabilized. Moreover, in the case of the p-type cross-hopping integrals, we.

AB - Using the mean-field approximation, we study the k-space spin textures and local spin currents emerged in the spin-triplet excitonic insulator states of the two-band Hubbard model defined on the square and triangular lattices. We assume a noninteracting band structure with a direct band gap and introduce s-, p-, d-, and f-type cross-hopping integrals, i.e., the hopping of electrons between different orbitals on adjacent sites with four different symmetries. First, we calculate the ground-state phase diagrams in the parameter space of the band filling and interaction strengths, whereby we present the filling dependence of the amplitude and phase of the excitonic order parameters. Then, we demonstrate that the spin textures (or asymmetric band structures) are emerged in the Fermi surfaces by the excitonic symmetry breaking when particular phases of the order parameter are stabilized. Moreover, in the case of the p-type cross-hopping integrals, we.

UR - http://www.scopus.com/inward/record.url?scp=85059890400&partnerID=8YFLogxK

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U2 - 10.1103/PhysRevB.99.035119

DO - 10.1103/PhysRevB.99.035119

M3 - Article

AN - SCOPUS:85059890400

VL - 99

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 2469-9950

IS - 3

M1 - 035119

ER -