Two-gap superconductivity in CaFe0.88Co0.12AsF revealed by temperature dependence of the lower critical field Hc1c (T)
Source abstract
Abstract
Abstract Gap symmetry and structure are crucial issues in understanding the superconducting mechanism of unconventional superconductors. Here, we report an in-depth investigation on the out-of-plane lower critical field $$Hc1^c$$ of fluorine-based 1111 system superconductor CaFe0.88Co0.12AsF with Tc = 21 K. A pronounced two-gap feature is revealed by the kink in the temperature-dependent $$Hc1^c(T)$$ curve. The magnitudes of the two gaps are determined to be Δ1 = 0.86 meV and Δ2 = 4.48 meV, which account for 74% and 26% of the total superfluid density, respectively. Our results suggest that the local antiferromagnetic exchange pairing picture is favored compared to the Fermi surface nesting scenario.
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Research context
OpenAlex topics: Iron-based superconductors research · Superconductivity in MgB2 and Alloys · Physics of Superconductivity and Magnetism
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References (44)
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