Tunneling break-junction spectroscopy on the superconductor NdFeAs(O 0.9F0.1)

Toshikazu Ekino; Akira Sugimoto; Hirotaka Okabe; Kazuhiro Shohara; Ryuichi Ukita; Jun Akimitsu; Alexander M. Gabovich

doi:10.1016/j.physc.2009.10.079

Tunneling break-junction spectroscopy on the superconductor NdFeAs(O _0.9F_0.1)

Toshikazu Ekino, Akira Sugimoto, Hirotaka Okabe, Kazuhiro Shohara, Ryuichi Ukita, Jun Akimitsu, Alexander M. Gabovich

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

13 Citations (Scopus)

Abstract

Tunnel break-junction method has been adopted to study polycrystalline samples of iron-oxypnictide superconductor NdFeAs(O_0.9F _0.1) with Tc=48K. Measurements were carried out at 4.2 K. Break-junction (BJ) conductance versus voltage curves showed gap-edge peaks with the peak-to-peak distances V_p-p=4Δ/e=28-40mV at 4.2 K, where 2Δ(T) is the superconducting energy gap, e>0 is the elementary charge. This yields 2Δ(0)=14-20meV, so that the gap ratio 2Δ(0)/kBTc is about 4.1±0.7,kB being the Boltzmann constant. This ratio implies strong-coupling superconductivity in the framework of Bardeen-Cooper-Schrieffer theory, being, however, much smaller than that for high-Tc copper oxides. This suggests a significant difference in the pairing mechanism between those classes of materials.

Original language	English
Pages (from-to)	S358-S359
Journal	Physica C: Superconductivity and its applications
Volume	470
Issue number	SUPPL.1
DOIs	https://doi.org/10.1016/j.physc.2009.10.079
Publication status	Published - Dec 2010
Externally published	Yes

Keywords

Break-junction
Energy gap
Iron-oxypnictide superconductors
Tunneling

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.2009.10.079

Cite this

@article{72ed7120421a4a51b141596485615f31,

title = "Tunneling break-junction spectroscopy on the superconductor NdFeAs(O 0.9F0.1)",

abstract = "Tunnel break-junction method has been adopted to study polycrystalline samples of iron-oxypnictide superconductor NdFeAs(O0.9F 0.1) with Tc=48K. Measurements were carried out at 4.2 K. Break-junction (BJ) conductance versus voltage curves showed gap-edge peaks with the peak-to-peak distances Vp-p=4Δ/e=28-40mV at 4.2 K, where 2Δ(T) is the superconducting energy gap, e>0 is the elementary charge. This yields 2Δ(0)=14-20meV, so that the gap ratio 2Δ(0)/kBTc is about 4.1±0.7,kB being the Boltzmann constant. This ratio implies strong-coupling superconductivity in the framework of Bardeen-Cooper-Schrieffer theory, being, however, much smaller than that for high-Tc copper oxides. This suggests a significant difference in the pairing mechanism between those classes of materials.",

keywords = "Break-junction, Energy gap, Iron-oxypnictide superconductors, Tunneling",

author = "Toshikazu Ekino and Akira Sugimoto and Hirotaka Okabe and Kazuhiro Shohara and Ryuichi Ukita and Jun Akimitsu and Gabovich, {Alexander M.}",

note = "Funding Information: This work was supported by a Grant-in-Aid for Scientific Research (Nos. 19540370, 19105006, 19014016 ) of Japan Society of Promotion of Science . AMG highly appreciates FY2007 fellowship no. S-07042 Granted by the Japan Society for the Promotion of Science as well as the support given in 2009 by the Visitors Program of the Max Planck Institute for the Physics of Complex Systems (Dresden, Germany).",

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language = "English",

volume = "470",

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AU - Ekino, Toshikazu

AU - Sugimoto, Akira

AU - Okabe, Hirotaka

AU - Shohara, Kazuhiro

AU - Ukita, Ryuichi

AU - Akimitsu, Jun

AU - Gabovich, Alexander M.

N1 - Funding Information: This work was supported by a Grant-in-Aid for Scientific Research (Nos. 19540370, 19105006, 19014016 ) of Japan Society of Promotion of Science . AMG highly appreciates FY2007 fellowship no. S-07042 Granted by the Japan Society for the Promotion of Science as well as the support given in 2009 by the Visitors Program of the Max Planck Institute for the Physics of Complex Systems (Dresden, Germany).

PY - 2010/12

Y1 - 2010/12

N2 - Tunnel break-junction method has been adopted to study polycrystalline samples of iron-oxypnictide superconductor NdFeAs(O0.9F 0.1) with Tc=48K. Measurements were carried out at 4.2 K. Break-junction (BJ) conductance versus voltage curves showed gap-edge peaks with the peak-to-peak distances Vp-p=4Δ/e=28-40mV at 4.2 K, where 2Δ(T) is the superconducting energy gap, e>0 is the elementary charge. This yields 2Δ(0)=14-20meV, so that the gap ratio 2Δ(0)/kBTc is about 4.1±0.7,kB being the Boltzmann constant. This ratio implies strong-coupling superconductivity in the framework of Bardeen-Cooper-Schrieffer theory, being, however, much smaller than that for high-Tc copper oxides. This suggests a significant difference in the pairing mechanism between those classes of materials.

AB - Tunnel break-junction method has been adopted to study polycrystalline samples of iron-oxypnictide superconductor NdFeAs(O0.9F 0.1) with Tc=48K. Measurements were carried out at 4.2 K. Break-junction (BJ) conductance versus voltage curves showed gap-edge peaks with the peak-to-peak distances Vp-p=4Δ/e=28-40mV at 4.2 K, where 2Δ(T) is the superconducting energy gap, e>0 is the elementary charge. This yields 2Δ(0)=14-20meV, so that the gap ratio 2Δ(0)/kBTc is about 4.1±0.7,kB being the Boltzmann constant. This ratio implies strong-coupling superconductivity in the framework of Bardeen-Cooper-Schrieffer theory, being, however, much smaller than that for high-Tc copper oxides. This suggests a significant difference in the pairing mechanism between those classes of materials.

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