Enhanced superconductivity accompanying a Lifshitz transition in electron-doped FeSe monolayer

X. Shi; Z. Q. Han; X. L. Peng; P. Richard; T. Qian; X. X. Wu; M. W. Qiu; S. C. Wang; J. P. Hu; Y. J. Sun; H. Ding

doi:10.1038/ncomms14988

Enhanced superconductivity accompanying a Lifshitz transition in electron-doped FeSe monolayer

X. Shi, Z. Q. Han, X. L. Peng, P. Richard, T. Qian, X. X. Wu, M. W. Qiu, S. C. Wang, J. P. Hu, Y. J. Sun^*, H. Ding

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

84 Citations (Scopus)

Abstract

The origin of enhanced superconductivity over 50 K in the recently discovered FeSe monolayer films grown on SrTiO 3 (STO), as compared to 8 K in bulk FeSe, is intensely debated. As with the ferrochalcogenides A x Fe 2â 'y Se 2 and potassium-doped FeSe, which also have a relatively high-superconducting critical temperature (T c), the Fermi surface (FS) of the FeSe/STO monolayer films is free of hole-like FS, suggesting that a Lifshitz transition by which these hole FSs vanish may help increasing T c. However, the fundamental reasons explaining this increase of T c remain unclear. Here we report a 15 K jump of T c accompanying a second Lifshitz transition characterized by the emergence of an electron pocket at the Brillouin zone centre, which is triggered by high-electron doping following in situ deposition of potassium on FeSe/STO monolayer films. Our results suggest that the pairing interactions are orbital dependent in generating enhanced superconductivity in FeSe.

Original language	English
Article number	14988
Journal	Nature Communications
Volume	8
DOIs	https://doi.org/10.1038/ncomms14988
Publication status	Published - 19 Apr 2017
Externally published	Yes

Access to Document

10.1038/ncomms14988

Cite this

@article{f4e90c773c6f4871b12db2e3d8fa94aa,

title = "Enhanced superconductivity accompanying a Lifshitz transition in electron-doped FeSe monolayer",

abstract = "The origin of enhanced superconductivity over 50 K in the recently discovered FeSe monolayer films grown on SrTiO 3 (STO), as compared to 8 K in bulk FeSe, is intensely debated. As with the ferrochalcogenides A x Fe 2{\^a} 'y Se 2 and potassium-doped FeSe, which also have a relatively high-superconducting critical temperature (T c), the Fermi surface (FS) of the FeSe/STO monolayer films is free of hole-like FS, suggesting that a Lifshitz transition by which these hole FSs vanish may help increasing T c. However, the fundamental reasons explaining this increase of T c remain unclear. Here we report a 15 K jump of T c accompanying a second Lifshitz transition characterized by the emergence of an electron pocket at the Brillouin zone centre, which is triggered by high-electron doping following in situ deposition of potassium on FeSe/STO monolayer films. Our results suggest that the pairing interactions are orbital dependent in generating enhanced superconductivity in FeSe.",

author = "X. Shi and Han, {Z. Q.} and Peng, {X. L.} and P. Richard and T. Qian and Wu, {X. X.} and Qiu, {M. W.} and Wang, {S. C.} and Hu, {J. P.} and Sun, {Y. J.} and H. Ding",

year = "2017",

month = apr,

day = "19",

doi = "10.1038/ncomms14988",

language = "English",

volume = "8",

journal = "Nature Communications",

issn = "2041-1723",

publisher = "Nature Publishing Group",

}

TY - JOUR

T1 - Enhanced superconductivity accompanying a Lifshitz transition in electron-doped FeSe monolayer

AU - Shi, X.

AU - Han, Z. Q.

AU - Peng, X. L.

AU - Richard, P.

AU - Qian, T.

AU - Wu, X. X.

AU - Qiu, M. W.

AU - Wang, S. C.

AU - Hu, J. P.

AU - Sun, Y. J.

AU - Ding, H.

PY - 2017/4/19

Y1 - 2017/4/19

N2 - The origin of enhanced superconductivity over 50 K in the recently discovered FeSe monolayer films grown on SrTiO 3 (STO), as compared to 8 K in bulk FeSe, is intensely debated. As with the ferrochalcogenides A x Fe 2â 'y Se 2 and potassium-doped FeSe, which also have a relatively high-superconducting critical temperature (T c), the Fermi surface (FS) of the FeSe/STO monolayer films is free of hole-like FS, suggesting that a Lifshitz transition by which these hole FSs vanish may help increasing T c. However, the fundamental reasons explaining this increase of T c remain unclear. Here we report a 15 K jump of T c accompanying a second Lifshitz transition characterized by the emergence of an electron pocket at the Brillouin zone centre, which is triggered by high-electron doping following in situ deposition of potassium on FeSe/STO monolayer films. Our results suggest that the pairing interactions are orbital dependent in generating enhanced superconductivity in FeSe.

AB - The origin of enhanced superconductivity over 50 K in the recently discovered FeSe monolayer films grown on SrTiO 3 (STO), as compared to 8 K in bulk FeSe, is intensely debated. As with the ferrochalcogenides A x Fe 2â 'y Se 2 and potassium-doped FeSe, which also have a relatively high-superconducting critical temperature (T c), the Fermi surface (FS) of the FeSe/STO monolayer films is free of hole-like FS, suggesting that a Lifshitz transition by which these hole FSs vanish may help increasing T c. However, the fundamental reasons explaining this increase of T c remain unclear. Here we report a 15 K jump of T c accompanying a second Lifshitz transition characterized by the emergence of an electron pocket at the Brillouin zone centre, which is triggered by high-electron doping following in situ deposition of potassium on FeSe/STO monolayer films. Our results suggest that the pairing interactions are orbital dependent in generating enhanced superconductivity in FeSe.

UR - http://www.scopus.com/inward/record.url?scp=85017639571&partnerID=8YFLogxK

U2 - 10.1038/ncomms14988

DO - 10.1038/ncomms14988

M3 - Article

C2 - 28422183

AN - SCOPUS:85017639571

SN - 2041-1723

VL - 8

JO - Nature Communications

JF - Nature Communications

M1 - 14988

ER -

Enhanced superconductivity accompanying a Lifshitz transition in electron-doped FeSe monolayer

Abstract

Access to Document

Other files and links

Fingerprint

Cite this