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

Hisao Nishida, Shohei Miyakoshi, Tatsuya Kaneko, Koudai Sugimoto, Yukinori Ohta

Research output: Contribution to journalArticle

1 Citation (Scopus)

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 languageEnglish
Article number035119
JournalPhysical Review B
Volume99
Issue number3
DOIs
Publication statusPublished - 2019 Jan 10
Externally publishedYes

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Hubbard model
Crystal symmetry
Band structure
textures
Textures
Fermi surface
Crystal lattices
Ground state
Phase diagrams
Energy gap
Electrons
Fermi surfaces
broken symmetry
phase diagrams
insulators
orbitals
ground state
symmetry
approximation
electrons

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

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

In: Physical Review B, Vol. 99, No. 3, 035119, 10.01.2019.

Research output: Contribution to journalArticle

Nishida, Hisao ; Miyakoshi, Shohei ; Kaneko, Tatsuya ; Sugimoto, Koudai ; Ohta, Yukinori. / Spin texture and spin current in excitonic phases of the two-band Hubbard model. In: Physical Review B. 2019 ; Vol. 99, No. 3.
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