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Interface-enhanced electron-phonon coupling and high-temperature superconductivity in potassium-coated ultrathin FeSe films on SrTiO3

Journal Article


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Abstract


  • Alkali-metal (potassium) adsorption on FeSe thin films with thickness from 2 unit cells (UC) to 4 UC on

    SrTiO3 grown by molecular beam epitaxy is investigated with a low-temperature scanning tunneling microscope.

    At appropriate potassium coverage (0.20–0.25 monolayer), the tunneling spectra of the films all exhibit a

    superconductinglike gap which is overall larger than 11 meV (five times the gap value of bulk FeSe) and decreases

    with increasing thickness, and two distinct features of characteristic phonon modes at ∼11 and ∼21 meV. The

    results reveal the critical role of the interface-enhanced electron-phonon coupling for possible high-temperature

    superconductivity in ultrathin FeSe films on SrTiO3 and is consistent with recent theories. Our study provides

    compelling evidence for the conventional pairing mechanism for this type of heterostructure superconducting

    system.

UOW Authors


  •   Tang, Chenjia (external author)
  •   Liu, Chong (external author)
  •   Zhou, Guanyu (external author)
  •   Li, Fangsen (external author)
  •   Ding, Hao (external author)
  •   Li, Zhi
  •   Zhang, Ding (external author)
  •   Li, Zheng
  •   Song, Canli (external author)
  •   Ji, Shuaihua (external author)
  •   He, Ke (external author)
  •   Wang, Lili (external author)
  •   Ma, Xu-Cun (external author)
  •   Xue, Qi-Kun (external author)

Publication Date


  • 2016

Geographic Focus


Citation


  • Tang, C., Liu, C., Zhou, G., Li, F., Ding, H., Li, Z., Zhang, D., Li, Z., Song, C., Ji, S., He, K., Wang, L., Ma, X. & XUE, Q. (2016). Interface-enhanced electron-phonon coupling and high-temperature superconductivity in potassium-coated ultrathin FeSe films on SrTiO3. Physical Review B: Condensed Matter and Materials Physics, 93 020507-1-020507-6.

Scopus Eid


  • 2-s2.0-85000839256

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=3573&context=aiimpapers

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/2549

Start Page


  • 020507-1

End Page


  • 020507-6

Volume


  • 93

Abstract


  • Alkali-metal (potassium) adsorption on FeSe thin films with thickness from 2 unit cells (UC) to 4 UC on

    SrTiO3 grown by molecular beam epitaxy is investigated with a low-temperature scanning tunneling microscope.

    At appropriate potassium coverage (0.20–0.25 monolayer), the tunneling spectra of the films all exhibit a

    superconductinglike gap which is overall larger than 11 meV (five times the gap value of bulk FeSe) and decreases

    with increasing thickness, and two distinct features of characteristic phonon modes at ∼11 and ∼21 meV. The

    results reveal the critical role of the interface-enhanced electron-phonon coupling for possible high-temperature

    superconductivity in ultrathin FeSe films on SrTiO3 and is consistent with recent theories. Our study provides

    compelling evidence for the conventional pairing mechanism for this type of heterostructure superconducting

    system.

UOW Authors


  •   Tang, Chenjia (external author)
  •   Liu, Chong (external author)
  •   Zhou, Guanyu (external author)
  •   Li, Fangsen (external author)
  •   Ding, Hao (external author)
  •   Li, Zhi
  •   Zhang, Ding (external author)
  •   Li, Zheng
  •   Song, Canli (external author)
  •   Ji, Shuaihua (external author)
  •   He, Ke (external author)
  •   Wang, Lili (external author)
  •   Ma, Xu-Cun (external author)
  •   Xue, Qi-Kun (external author)

Publication Date


  • 2016

Geographic Focus


Citation


  • Tang, C., Liu, C., Zhou, G., Li, F., Ding, H., Li, Z., Zhang, D., Li, Z., Song, C., Ji, S., He, K., Wang, L., Ma, X. & XUE, Q. (2016). Interface-enhanced electron-phonon coupling and high-temperature superconductivity in potassium-coated ultrathin FeSe films on SrTiO3. Physical Review B: Condensed Matter and Materials Physics, 93 020507-1-020507-6.

Scopus Eid


  • 2-s2.0-85000839256

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=3573&context=aiimpapers

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/2549

Start Page


  • 020507-1

End Page


  • 020507-6

Volume


  • 93