Direct evidence of two superconducting gaps in FeSe0.5Te0.5: SnS-Andreev spectroscopy and the lower critical field
We present direct measurements of the superconducting order parameter in nearly optimal FeSe Te single crystals with the critical temperature T C ≈ 14 K. Using the intrinsic multiple Andreev reflection effect (IMARE) spectroscopy and measurements of the lower critical field, we directly determined t...
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Published in | JETP letters Vol. 104; no. 12; pp. 852 - 858 |
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Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Moscow
Pleiades Publishing
01.12.2016
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | We present direct measurements of the superconducting order parameter in nearly optimal FeSe Te single crystals with the critical temperature
T
C
≈ 14 K. Using the intrinsic multiple Andreev reflection effect (IMARE) spectroscopy and measurements of the lower critical field, we directly determined two superconducting gaps, Δ
L
≈ 3.3−3.4 meV and Δ
S
≈ 1 meV, and their temperature dependences. We show that a twoband model fits well the experimental data. The estimated electron–boson coupling constants indicate a strong intraband and a moderate interband interaction. |
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ISSN: | 0021-3640 1090-6487 |
DOI: | 10.1134/S0021364016240048 |