Skip to main content

Magnetic order driven by orbital ordering in the semiconducting KFe1.5Se2

Frontiers of Physics volume 11, Article number: 117401 (2016) Cite this article

Abstract

The two-orbital Hubbard model is studied numerically by using the Hartree-Fock approximation in both real space and momentum space, and the ground-state properties of the alkali metal iron selenide semiconducting KFe1.5Se2 are investigated. A rhombus-type Fe vacancy order with stripetype antiferromagnetic (AFM) order is found, as was observed in neutron scattering experiments [J. Zhao, et al., Phys. Rev. Lett. 109, 267003 (2012)]. Hopping parameters are obtained by fitting the experimentally observed stripe AFM phase in real space. These hopping parameters are then used to study the ground-state properties of the semiconductor in momentum space. It is found to be a strongly correlated system with a large on-site Coulomb repulsion U, similar to the AFM Mott insulator — the parent compound of copper oxide superconductors. We also find that the electronic occupation numbers and magnetizations in the d xz and d yz orbitals become different simultaneously when U > U c (∼3.4 eV), indicating orbital ordering. These results imply that the rotational symmetry between the two orbitals is broken by orbital ordering and thus drives the strong anisotropy of the magnetic coupling that has been observed by experiments and that the stripe-type AFM order in this compound may be caused by orbital ordering together with the observed large anisotropy.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

USD 39.95

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

References

  1. J. G. Guo, S. F. Jin, G. Wang, S. C. Wang, K. X. Zhu, T. T. Zhou, M. He, and X. L. Chen, Superconductivity in the iron selenide KxFe2Se2 (0 ≤ x ≤ 1.0), Phys. Rev. B 82(18), 180520 (2010)

    Article  ADS  Google Scholar 

  2. A. Krzton-Maziopa, Z. Shermadini, E. Pomjakushina, V. Pomjakushin, M. Bendele, A. Amato, R. Khasanov, H. Luetkens, and K. Conder, Synthesis and crystal growth of Cs0.8(FeSe0.98)2: A new iron-based superconductor with T c= 27 K, J. Phys.: Condens. Matter 23(5), 052203 (2011)

    ADS  Google Scholar 

  3. H. D. Wang, C. H. Dong, Z. J. Li, Q. H. Mao, S. S. Zhu, C. M. Feng, H. Q. Yuan, and M. H. Fang, Superconductivity at 32 K and anisotropy in Tl0.58Rb0.42Fe1.72Se2 crystals, Europhys. Lett. 93(4), 47004 (2011)

    Article  ADS  Google Scholar 

  4. A. F. Wang, J. J. Ying, Y. J. Yan, R. H. Liu, X. G. Luo, Z. Y. Li, X. F. Wang, M. Zhang, G. J. Ye, P. Cheng, Z. J. Xiang, and X. H. Chen, Superconductivity at 32 K in single-crystalline RbxFe2-y Se2, Phys. Rev. B 83, 060512(R) (2011)

    Google Scholar 

  5. E. Dagotto, Colloquium: The unexpected properties of alkali metal iron selenide superconductors, Rev. Mod. Phys. 85(2), 849 (2013)

    Article  ADS  Google Scholar 

  6. M. Guidry and Y. Sun, Superconductivity and superfluidity as universal emergent phenomena, Front. Phys. 10(4), 107404 (2015)

    Article  Google Scholar 

  7. Y. Zhang, L. X. Yang, M. Xu, Z. R. Ye, F. Chen, C. He, H. C. Xu, J. Jiang, B. P. Xie, J. J. Ying, X. F. Wang, X. H. Chen, J. P. Hu, M. Matsunami, S. Kimura, and D. L. Feng, Nodeless superconducting gap in AxFe2Se2 (A=K,Cs) revealed by angle-resolved photoemission spectroscopy, Nat. Mater. 10(4), 273 (2011)

    Article  ADS  Google Scholar 

  8. T. Qian, X. P. Wang, W. C. Jin, P. Zhang, P. Richard, G. Xu, X. Dai, Z. Fang, J. G. Guo, X. L. Chen, and H. Ding, Absence of a holelike fermi surface for the iron-based K0.8F1.7Se2 superconductor revealed by angle-resolved photoemission spectroscopy, Phys. Rev. Lett. 106(18), 187001 (2011)

    Article  ADS  Google Scholar 

  9. X. P. Wang, T. Qian, P. Richard, P. Zhang, J. Dong, H. D. Wang, C. H. Dong, M. H. Fang, and H. Ding, Strong nodeless pairing on separate electron Fermi surface sheets in (Tl, K)Fe1.78Se2 probed by ARPES, Europhys. Lett. 93(5), 57001 (2011)

    Article  ADS  Google Scholar 

  10. F. J. Ma and Z. Y. Lu, Iron-based layered compound LaFeAsO is an antiferromagnetic semimetal, Phys. Rev. B 78(3), 033111 (2008)

    Article  ADS  MathSciNet  Google Scholar 

  11. J. Dong, H. J. Zhang, G. Xu, Z. Li, G. Li, W. Z. Hu, D. Wu, G. F. Chen, X. Dai, J. L. Luo, Z. Fang, and N. L. Wang, Competing orders and spin-density-wave instability in La(O1-x Fx)FeAs, Europhys. Lett. 83(2), 27006 (2008)

    Article  ADS  Google Scholar 

  12. F. Chen, M. Xu, Q. Q. Ge, Y. Zhang, Z. R. Ye, L. X. Yang, J. Jiang, B. P. Xie, R. C. Che, M. Zhang, A. F. Wang, X. H. Chen, D. W. Shen, J. P. Hu, and D. L. Feng, Electronic identification of the parental phases and mesoscopic phase separation of KxFe2-y Se2 superconductors, Phys. Rev. X 1(2), 021020 (2011)

    Google Scholar 

  13. A. Ricci, N. Poccia, G. Campi, B. Joseph, G. Arrighetti, L. Barba, M. Reynolds, M. Burghammer, H. Takeya, Y. Mizuguchi, Y. Takano, M. Colapietro, N. L. Saini, and A. Bianconi, Nanoscale phase separation in the iron chalcogenide superconductor K0.8Fe1.6Se2 as seen via scanning nanofocused X-ray diffraction, Phys. Rev. B 84, 060511(R) (2011)

    Article  ADS  Google Scholar 

  14. D. X. Mou, L. Zhao, and X. J. Zhou, Structural, magnetic and electronic properties of the iron-chalcogenide AxFe2-y Se2 (A=K, Cs, Rb, and Tl, etc.) superconductors, Front. Phys. 6(4), 410 (2011)

    Article  Google Scholar 

  15. W. Bao, Q. Z. Huang, G. F. Chen, M. A. Green, D. M. Wang, J. B. He, and Y. M. Qiu, A novel large moment antiferromagnetic order in K0.8Fe1.6Se2 superconductor, Chin. Phys. Lett. 28(8), 086104 (2011)

    Article  ADS  Google Scholar 

  16. W. Bao, G. N. Li, Q. Z. Huang, G. F. Chen, J. B. He, D. M. Wang, M. A. Green, Y. M. Qiu, J. L. Luo, and M. M. Wu, Superconductivity tuned by the iron vacancy order in KxF2-y Se2, Chin. Phys. Lett. 30(2), 027402 (2013)

    Article  ADS  Google Scholar 

  17. J. Zhao, H. Cao, E. Bourret-Courchesne, D. H. Lee, and R. J. Birgeneau, Neutron-diffraction measurements of an antiferromagnetic semiconducting phase in the vicinity of the hightemperature superconducting state of KxFe2-y Se2, Phys. Rev. Lett. 109(26), 267003 (2012)

    Article  ADS  Google Scholar 

  18. M. Wang, W. Tian, P. Valdivia, S. X. Chi, E. Bourret- Courchesne, P. C. Dai, and R. J. Birgeneau, Two spatially separated phases in semiconducting Rb0.8Fe1.5S2, Phys. Rev. B 90(12), 125148 (2014)

    Article  ADS  Google Scholar 

  19. J. Zhao, Y. Shen, R. J. Birgeneau, M. Gao, Z. Y. Lu, D. H. Lee, X. Z. Lu, H. J. Xiang, D. L. Abernathy, and Y. Zhao, Neutron scattering measurements of spatially anisotropic magnetic exchange interactions in semiconducting K0.85Fe1.54Se2 (T N = 280 K), Phys. Rev. Lett. 112(17), 177002 (2014)

    Article  ADS  Google Scholar 

  20. M. Wang, P. Valdivia, J. X. Chen, W. L. Zhang, R. A. Ewings, T. G. Perring, Y. Zhao, L. W. Harriger, J. W. Lynn, E. Bourret-Courchesne, D. H. Lee, D. X. Yao, and R. J. Birgeneau, Spin waves and spatially anisotropic exchange interactions in the S = 2 stripe antiferromagnet Rb0.8Fe1.5S2, Phys. Rev. B 92, 041109(R) (2015)

    Article  ADS  Google Scholar 

  21. L. Boeri, O. V. Dolgov, and A. A. Golubov, Is LaFeAsO1-x Fx an electron-phonon superconductor? Phys. Rev. Lett. 101(2), 026403 (2008)

    Article  ADS  Google Scholar 

  22. Y. Liang, X. X. Wu, W. F. Tsai, and J. P. Hu, Pairing symmetry in layered BiS2compounds driven by electron-electron correlation, Front. Phys. 9(2), 194 (2014)

    Article  Google Scholar 

  23. S. Raghu, X.-L. Qi, C.-X. Liu, D. J. Scalapino, and S.-C. Zhang, A minimal two-band model for the superconducting Fe-pnictides, Phys. Rev. B 77, 220503(R) (2008)

    Article  ADS  Google Scholar 

  24. M. Daghofer, A. Moreo, J. A. Riera, E. Arrigoni, D. J. Scalapino, and E. Dagotto, Model for the magnetic order and pairing channels in Fe pnictide superconductors, Phys. Rev. Lett. 101(23), 237004 (2008)

    Article  ADS  Google Scholar 

  25. Q. Jiang, Y. T. Kang, and D. X. Yao, Spin, charge, and orbital orderings in iron-based superconductors, Chin. Phys. B 22(8), 087402 (2013)

    Article  ADS  Google Scholar 

  26. Q. L. Luo, D. X. Yao, A. Moreo, and E. Dagotto, Charge stripes in the two-orbital Hubbard model for iron pnictides, Phys. Rev. B 83(17), 174513 (2011)

    Article  ADS  Google Scholar 

  27. M. Wang, C. Fang, D. X. Yao, G. Tan, L. W. Harriger, Y. Song, T. Netherton, C. Zhang, M. Wang, M. B. Stone, W. Tian, J. Hu, and P. Dai, Spin waves and magnetic exchange interactions in insulating Rb0.89Fe1.58Se2, Nat. Commun. 2, 580 (2011)

    Article  ADS  Google Scholar 

  28. W. Li, C. Setty, X. H. Chen, and J. P. Hu, Electronic and magnetic structures of chain structured iron selenide compounds, Front. Phys. 9(4), 465 (2014)

    Article  Google Scholar 

  29. R. Yu, K. T. Trinh, A. Moreo, M. Daghofer, J. A. Riera, S. Haas, and E. Dagotto, Magnetic and metallic state at intermediate Hubbard U coupling in multiorbital models for undoped iron pnictides, Phys. Rev. B 79(10), 104510 (2009)

    Article  ADS  Google Scholar 

  30. X. W. Yan, M. Gao, Z. Y. Lu, and T. Xiang, Electronic structures and magnetic order of ordered-Fe-vacancy ternary iron selenides TlFe1.5Se2 and AFe1.5Se2 (A=K, Rb, or Cs), Phys. Rev. Lett. 106(8), 087005 (2011)

    Article  ADS  Google Scholar 

  31. C. C. Lee, W. G. Yin, and W. Ku, Ferro-orbital order and strong magnetic anisotropy in the parent compounds of ironpnictide superconductors, Phys. Rev. Lett. 103(26), 267001 (2009)

    Article  ADS  Google Scholar 

  32. W. C. Lv, W. C. Lee, and P. Phillips, Vacancy-driven orbital and magnetic order in (K,Tl,Cs)yFe2-x Se2, Phys. Rev. B 84(15), 155107 (2011)

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou, 510275, China

    Qing Jiang & Dao-Xin Yao

Authors
  1. Qing Jiang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Dao-Xin Yao
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Dao-Xin Yao.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Jiang, Q., Yao, DX. Magnetic order driven by orbital ordering in the semiconducting KFe1.5Se2 . Front. Phys. 11, 117401 (2016). https://doi.org/10.1007/s11467-015-0527-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s11467-015-0527-4

Keywords

  • iron-based superconductor
  • two-orbital model
  • stripe AFM phase
  • rhombus Fe vacancy order
  • orbital ordering