Plain s-wave superconductivity in single-layer FeSe on SrTiO 3 probed by scanning tunnelling microscopy

Nature Physics

Volumn 11, Issue 11, 2015, Pages 946-952

  Fan, Q ^a   Zhang, W H ^a   Liu, X ^a   Yan, Y J ^a   Ren, M Q ^a   Peng, R ^a   Xu, H C ^a   Xie, B P ^a   Hu, J P ^b,c   Zhang, T ^a   Feng, D L ^a  

^a FUDAN UNIVERSITY   (China)

^b INSTITUTE OF PHYSICS   (China)

^c PURDUE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

FERMI SURFACE; IRON COMPOUNDS; MAGNETISM; SCANNING TUNNELING MICROSCOPY; SELENIUM COMPOUNDS; SHEAR WAVES; STRONTIUM COMPOUNDS; TEMPERATURE; TITANIUM COMPOUNDS;

ELECTRON POCKETS; FERMI SURFACE SECTIONS; FERMI SURFACE TOPOLOGY; INTERFERENCE PATTERNS; MAGNETIC IMPURITY; MAGNETIC VORTICES; NON-MAGNETIC IMPURITIES; PAIRING SYMMETRIES;

IRON-BASED SUPERCONDUCTORS;

EID: 84947033590     PISSN: 17452473     EISSN: 17452481     Source Type: Journal    
DOI: 10.1038/nphys3450     Document Type: Article

References (41)

1. Hsu, F. C. et al. Superconductivity in the PbO-type structure FeSe. Proc. Natl Acad. Sci. USA 105, 14262-14264 (2008).
2. Wang, Q. Y. et al. Interface induced high temperature superconductivity in single unit-cell FeSe films on SrTiO3. Chin. Phys. Lett. 29, 037402 (2012).
3. Liu, D. F. et al. Electronic origin of high-temperature superconductivity in single-layer FeSe superconductor. Nature Commun. 3, 931 (2012).
4. He, S. L. et al. Phase diagram and electronic indication of high-temperature superconductivity at 65K in single-layer FeSe films. Nature Mater. 12, 605-610 (2013).
5. Tan, S. Y. et al. Interface-induced superconductivity and strain-dependent spin density waves in FeSe/SrTiO3 thin films. Nature Mater. 12, 634-640 (2013).
6. Peng, R. et al. Measurement of an enhanced superconducting phase and a pronounced anisotropy of the energy gap of a strained FeSe single layer in FeSe/Nb: SrTiO3/KTaO3 heterostructures using photoemission spectroscopy. Phys. Rev. Lett. 112, 107001 (2014).
7. Peng, R. et al. Tuning the band structure and superconductivity in single-layer FeSe by interface engineering. Nature Commun. 5, 5044 (2014).
8. Lee, J. J. et al. Interfacial mode coupling as the origin of the enhancement of Tc in FeSe films on SrTiO3. Nature 515, 245-248 (2014).
9. Zhang,W. H. et al. Direct observation of high-temperature superconductivity in one-unit-cell FeSe films. Chin. Phys. Lett. 31, 017401 (2014).
10. Li, Z. et al. Molecular beam epitaxy growth and post-growth annealing of FeSe films on SrTiO3: A scanning tunneling microscopy study. J. Phys. Condens. Matter 26, 265002 (2014).
11. Ge, J. F. et al. Superconductivity above 100K in single-layer FeSe films on doped SrTiO3. Nature Mater. 14, 285-289 (2015).
12. Mazin, I. I. et al. Unconventional superconductivity with a sign reversal in the order parameter of LaFeAsO1 xFx . Phys. Rev. Lett. 101, 057003 (2008).
13. Hirschfeld, P. J. et al. Gap symmetry and structure of Fe-based superconductors. Rep. Prog. Phys. 74, 124508 (2011).
14. Fang, C. et al. Robustness of s-wave pairing in electron-overdoped A1 yFe2 xSe2 (A D K, Cs). Phys. Rev. X 1, 011009 (2011).
15. Zhou, Y. et al. Theory for superconductivity in (Tl,K)FexSe2 as a doped Mott insulator. Europhys. Lett. 95, 17003 (2011).
16. Yang, F. et al. Fermiology, orbital order, orbital fluctuations, and Cooper pairing in iron-based superconductors. Phys. Rev. B. 88, 100504 (2013).
17. Maier, T. A. et al. d-wave pairing from spin fluctuations in the KxFe2 ySe2 superconductors. Phys. Rev. B 83, 100515 (2011).
18. Wang, F. et al. The electron pairing of KxFe2 ySe2. Europhys. Lett. 93, 57003 (2011).
19. Mazin, I. I. Symmetry analysis of possible superconducting states in KxFeySe2 superconductors. Phys. Rev. B 84, 024529 (2011).
20. Yin, Z. P., Haule, K. & Kotliar, G. Spin dynamics and orbital-antiphase pairing symmetry in iron-based superconductors. Nature Phys. 10, 845-850 (2014).
21. Hu, J. P. Iron-based superconductors as odd-parity superconductors. Phys. Rev. X 3, 031004 (2013).
22. Balatsky, A. V. et al. Impurity-induced states in conventional and unconventional superconductors. Rev. Mod. Phys. 78, 373-433 (2006).
23. Yazdani, A. et al. Probing the local effects of magnetic impurities on superconductivity. Science 275, 1767-1770 (1997).
24. Pan, S. H. et al. Imaging the effects of individual zinc impurity atoms on superconductivity in Bi2Sr2CaCu2O8C . Nature 403, 746-750 (2000).
25. Hoffman, J. E. et al. Imaging quasiparticle interference in Bi2Sr2CaCu2O8C . Science 297, 1148-1157 (2002).
26. Wang, Q. H. et al. Quasiparticle scattering interference in high-temperature superconductors. Phys. Rev. B 67, 020511 (2003).
27. Hanaguri, T. et al. Coherence factors in a high-Tc cuprate probed by quasi-particle scattering o vortices. Science 323, 923-926 (2009).
28. Bang, J. et al. Atomic and electronic structures of single-layer FeSe on SrTiO3(001): The role of oxygen deficiency. Phys. Rev. B 87, 220503 (2013).
29. Song, C. L. et al. Direct observation of nodes and twofold symmetry in FeSe superconductor. Science 332, 1410-1413 (2011).
30. Hess, H. F. et al. Vortex-core structure observed with a scanning tunneling microscope. Phys. Rev. Lett. 64, 2711-2714 (1990).
31. Hanaguri, T. et al. Scanning tunneling microscopy/spectroscopy of vortices in LiFeAs. Phys. Rev. B 85, 214505 (2012).
32. Allan, M. P. et al. Anisotropic energy gaps of iron-based superconductivity from intraband quasiparticle interference in LiFeAs. Science 336, 563-567 (2012).
33. Hanaguri, T. et al. Unconventional s-wave superconductivity in Fe(Se,Te). Science 328, 474-476 (2010).
34. Chi, S. et al. Sign inversion in the superconducting order parameter of LiFeAs inferred from Bogoliubov quasiparticle interference. Phys. Rev. B 89, 104522 (2014).
35. Onari, S. et al. Violation of Anderson's theorem for the sign-reversing s-wave state of iron-pnictide superconductors. Phys. Rev. Lett. 103, 177001 (2009).
36. Kariyado, T. et al. Single impurity problem in iron-pnictide superconductors. J. Phys. Soc. Jpn 79, 083704 (2010).
37. Grothe, S. et al. Bound states of defects in superconducting LiFeAs studied by scanning tunneling spectroscopy. Phys. Rev. B 86, 174503 (2012).
38. Yang, H. et al. In-gap quasiparticle excitations induced by non-magnetic Cu impurities in Na(Fe0.96Co0.03Cu0.01) as revealed by scanning tunneling spectroscopy. Nature Commun. 4, 2749 (2013).
39. Zhu, J. X. et al. Local electronic structure of a single nonmagnetic impurity as a test of the pairing symmetry of electrons in (K,Tl)FexSe2 superconductors. Phys. Rev. Lett. 107, 167002 (2011).
40. Kontani, H. & Onari, S. Orbital-fluctuation-mediated superconductivity in iron pnictides: Analysis of the five-orbital Hubbard-Holstein model. Phys. Rev. Lett. 104, 157001 (2010).
41. Huang, D. et al. Revealing the empty-state electronic structure of single-unit-cell FeSe/SrTiO3. Phys. Rev. Lett. 115, 017002 (2015).