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
N1 - Funding Information:
We thank Yoji Ohashi for tutorial lectures and enlightening discussions. This work was supported by Grants-in-Aid for Scientific Research (Nos. JP26400349, JP15H06093, JP17K05530, and JP18K13509) from JSPS of Japan. The numerical calculations were carried out on computers at Yukawa Institute for Theoretical Physics, Kyoto University, Japan.
Publisher Copyright:
© 2019 American Physical Society.
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.
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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 -