Pairing symmetry in layered BiS₂ compounds driven by electron–electron correlation

Abstract

We investigate the pairing symmetry of layered BiS₂ compounds by assuming that electron-electron correlation is still important so that the pairing is rather short range. We find that the extended s-wave pairing symmetry always wins over d-wave when the pairing is confined between two short range sites up to next nearest neighbors. The pairing strength is peaked around the doping level x = 0.5, which is consistent with experimental observation. The extended s-wave pairing symmetry is very robust against spin–orbital coupling because it is mainly determined by the structure of Fermi surfaces. Moreover, the extended s-wave pairing can be distinguished from conventional s-wave pairing by measuring and comparing superconducting gaps of different Fermi surfaces.

Graphical abstract

Keywords

BiS₂-based superconductor / pairing symmetry / electron–electron correlation

References

[1] Y. Mizuguchi, H. Fujihisa, Y. Gotoh, K. Suzuki, H. Usui, K. Kuroki, S. Demura, Y. Takano, H. Izawa, and O. Miura, Novel BiS₂-based layered superconductor Bi₄O₄S₃, Phys. Rev. B, 2012, 86(22): 220510(R), arXiv: 1207.3145

[2] Y. Mizuguchi, S. Demura, K. Deguchi, Y. Takano, H. Fujihisa, Y. Gotoh, H. Izawa, and O. Miura, Superconductivity in novel BiS₂-based layered superconductor LaO_1–xF_xBiS₂, J. Phys. Soc. Jpn., 2012, 81: 114725, arXiv: 1207.3558

[3] S. Demura, Y. Mizuguchi, K. Deguchi, H. Okazaki, H. Hara, T. Watanabe, S. J. Denholme, M. Fujioka, T. Ozaki, H. Fujihisa, Y. Gotoh, O. Miura, T. Yamaguchi, H. Takeya, and Y. Takano, BiS₂-based superconductivity in F-substituted NdOBiS₂, J. Phys. Soc. Jpn., 2013, 82(3): 033708, arXiv: 1207.5248

[4] R. Jha, A. Kumar, S. K. Singh, and V. P. S. Awana, Superconductivity at 5 K in NdO_0.5F_0.5BiS₂, J. Appl. Phys., 2013, 113(5): 056102, arXiv: 1208.3077

[5] S. Li, H. Yang, J. Tao, X. Ding, and H. H. Wen, Multiband exotic superconductivity in the new superconductor Bi₄O₄S₃, Sci. China-Phys. Mech. Astron., 2013, 56: 2019, arXiv: 1207.4955

[6] S. G. Tan, L. J. Li, Y. Liu, P. Tong, B. C. Zhao, W. J. Lu, and Y. P. Sun, Superconducting and thermoelectric properties of new layered superconductor Bi₄O₄S₃, Physica C, 2012, 483: 94, arXiv: 1207.5395

[7] H. Kotegawa, Y. Tomita, H. Tou, H. Izawa, Y. Mizuguchi, O. Miura, S. Demura, K. Deguchi, and Y. Takano, Pressure study of BiS₂-based superconductors Bi₄O₄S₃ and La(O,F)BiS₂, J. Phys. Soc. Jpn., 2012, 81: 103702, arXiv: 1207.6935

[8] H. Usui, K. Suzuki, and K. Kuroki, Minimal electronic models for superconducting BiS₂ layers, Phys. Rev. B, 2012, 86(22): 220501(R), arXiv: 1207.3888

[9] T. Zhou and Z. D. Wang, Probing the superconducting pairing symmetry from spin excitations in BiS₂ based superconductors, J. Supercond. Nov. Magn., 2013, 26(8): 2735, arXiv: 1208.1101

[10] X. G. Wan, H. C. Ding, S. Y. Savrasov, and C. G. Duan, Density-functional calculations of the electronic structure and lattice dynamics of superconducting LaO_0.5F_0.5BiS₂: Evidence for an electron–phonon interaction near the chargedensity-wave instability, Phys. Rev. B, 2013, 87(11): 115124, arXiv: 1208.1807

[11] Y. Kamihara, T. Watanabe, M. Hirano, and H. Hosono, Iron-based layered superconductor La[O_1-xF_x]FeAs (x= 0.05-0.12) with T_c = 26 K, J. Am. Chem. Soc., 2008, 130(11): 3296

[12] P. J. Hirschfeld, M. M. Korshunov, and I. I. Mazin, Gap symmetry and structure of Fe-based superconductors, Rep. Prog. Phys., 2011, 74(12): 124508

[13] K. Seo, B. A. Bernevig, and J. P. Hu, Pairing symmetry in a two-orbital exchange coupling model of oxypnictides, Phys. Rev. Lett., 2008, 101(20): 206404

[14] J. P. Hu and H. Ding, Local antiferromagnetic exchange and collaborative Fermi surface as key ingredients of high temperature superconductors, Scientific Reports, 2012, 2: 381

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg