Determination of superconducting gap of SmFeAsFxO1-x superconductors by Andreev reflection spectroscopy

T. Y. Chen; S. X. Huang; Z. Tesanovic; R. H. Liu; X. H. Chen; C. L. Chien

doi:10.1016/j.physc.2009.03.041

Determination of superconducting gap of SmFeAsF_xO_1-x superconductors by Andreev reflection spectroscopy

T. Y. Chen, S. X. Huang, Z. Tesanovic, R. H. Liu, X. H. Chen, C. L. Chien

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

21 Scopus citations

Abstract

The superconducting gap in FeAs-based superconductor SmFeAs(O_1-xF_x) (x = 0.15 and 0.30) and the temperature dependence of the sample with x = 0.15 have been measured by Andreev reflection spectroscopy. The intrinsic superconducting gap is independent of contacts while many other "gap-like" features vary appreciably for different contacts. The determined gap value of 2Δ = 13.34 ± 0.47 meV for SmFeAs(O_0.85F_0.15) gives 2Δ/k_BT_C = 3.68, close to the BCS prediction of 3.53. The superconducting gap decreases with temperature and vanishes at T_C, in a manner similar to the BCS behavior but dramatically different from that of the nodal pseudogap behavior in cuprate superconductors.

Original language	English (US)
Pages (from-to)	521-528
Number of pages	8
Journal	Physica C: Superconductivity and its applications
Volume	469
Issue number	9-12
DOIs	https://doi.org/10.1016/j.physc.2009.03.041
State	Published - 2009
Externally published	Yes

Keywords

Andreev reflection spectroscopy
Fe-superconductors
Point contact
Superconducting gap

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Energy Engineering and Power Technology
Electrical and Electronic Engineering

Access to Document

10.1016/j.physc.2009.03.041

Cite this

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title = "Determination of superconducting gap of SmFeAsFxO1-x superconductors by Andreev reflection spectroscopy",

abstract = "The superconducting gap in FeAs-based superconductor SmFeAs(O1-xFx) (x = 0.15 and 0.30) and the temperature dependence of the sample with x = 0.15 have been measured by Andreev reflection spectroscopy. The intrinsic superconducting gap is independent of contacts while many other {"}gap-like{"} features vary appreciably for different contacts. The determined gap value of 2Δ = 13.34 ± 0.47 meV for SmFeAs(O0.85F0.15) gives 2Δ/kBTC = 3.68, close to the BCS prediction of 3.53. The superconducting gap decreases with temperature and vanishes at TC, in a manner similar to the BCS behavior but dramatically different from that of the nodal pseudogap behavior in cuprate superconductors.",

keywords = "Andreev reflection spectroscopy, Fe-superconductors, Point contact, Superconducting gap",

author = "Chen, {T. Y.} and Huang, {S. X.} and Z. Tesanovic and Liu, {R. H.} and Chen, {X. H.} and Chien, {C. L.}",

note = "Funding Information: The authors are grateful to I. Mazin and C. Broholm for useful discussions. This work was supported in part by the NSF Grants DMR-0520491 (CLC) and DMR-0531159 (ZT). Work at the Johns Hopkins Institute for Quantum Matter was supported by the US. Department of Energy Office of Science under Contract No. DE-FG02-08ER46544 (ZT).",

year = "2009",

doi = "10.1016/j.physc.2009.03.041",

language = "English (US)",

volume = "469",

pages = "521--528",

journal = "Physica C: Superconductivity and its applications",

issn = "0921-4534",

publisher = "Elsevier",

number = "9-12",

}

TY - JOUR

T1 - Determination of superconducting gap of SmFeAsFxO1-x superconductors by Andreev reflection spectroscopy

AU - Chen, T. Y.

AU - Huang, S. X.

AU - Tesanovic, Z.

AU - Liu, R. H.

AU - Chen, X. H.

AU - Chien, C. L.

N1 - Funding Information: The authors are grateful to I. Mazin and C. Broholm for useful discussions. This work was supported in part by the NSF Grants DMR-0520491 (CLC) and DMR-0531159 (ZT). Work at the Johns Hopkins Institute for Quantum Matter was supported by the US. Department of Energy Office of Science under Contract No. DE-FG02-08ER46544 (ZT).

PY - 2009

Y1 - 2009

N2 - The superconducting gap in FeAs-based superconductor SmFeAs(O1-xFx) (x = 0.15 and 0.30) and the temperature dependence of the sample with x = 0.15 have been measured by Andreev reflection spectroscopy. The intrinsic superconducting gap is independent of contacts while many other "gap-like" features vary appreciably for different contacts. The determined gap value of 2Δ = 13.34 ± 0.47 meV for SmFeAs(O0.85F0.15) gives 2Δ/kBTC = 3.68, close to the BCS prediction of 3.53. The superconducting gap decreases with temperature and vanishes at TC, in a manner similar to the BCS behavior but dramatically different from that of the nodal pseudogap behavior in cuprate superconductors.

AB - The superconducting gap in FeAs-based superconductor SmFeAs(O1-xFx) (x = 0.15 and 0.30) and the temperature dependence of the sample with x = 0.15 have been measured by Andreev reflection spectroscopy. The intrinsic superconducting gap is independent of contacts while many other "gap-like" features vary appreciably for different contacts. The determined gap value of 2Δ = 13.34 ± 0.47 meV for SmFeAs(O0.85F0.15) gives 2Δ/kBTC = 3.68, close to the BCS prediction of 3.53. The superconducting gap decreases with temperature and vanishes at TC, in a manner similar to the BCS behavior but dramatically different from that of the nodal pseudogap behavior in cuprate superconductors.

KW - Andreev reflection spectroscopy

KW - Fe-superconductors

KW - Point contact

KW - Superconducting gap

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