Unusually weak irradiation effects in anisotropic iron-based superconductor RbCa2Fe4As4F2

Daniele Torsello; Erik Piatti; Michela Fracasso; Roberto Gerbaldo; Laura Gozzelino; Xiaolei Yi; Xiangzhuo Xing; Zhixiang Shi; Dario Daghero; Gianluca Ghigo

doi:10.3389/fphy.2023.1336501

arXiv · 2401.08279

Unusually weak irradiation effects in anisotropic iron-based superconductor RbCa2Fe4As4F2

Daniele Torsello·Erik Piatti·Michela Fracasso·Roberto Gerbaldo·Laura Gozzelino·Xiaolei Yi·Xiangzhuo Xing·Zhixiang Shi·Dario Daghero·Gianluca Ghigo

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Abstract

We report on the effects of 3.5 MeV proton irradiation in RbCa$_2$Fe$_4$As$_4$F$_2$, an iron-based superconductor with unusual properties in between those of the pnictides and of the cuprate high-temperature superconductors. We studied how structural disorder introduced by ion bombardment affects the critical temperature, superfluid density and gap values by combining a coplanar waveguide resonator technique, electric transport measurements and point-contact Andreev-reflection spectroscopy. We find an unusually weak dependence of the superconducting properties on the amount of disorder in this material when compared to other iron-based superconductors under comparable irradiation conditions. The nodal multigap state exhibited by pristine RbCa$_2$Fe$_4$As$_4$F$_2$ is also robust against proton irradiation, with a two-band $d-d$ model being the one that best fits the experimental data.

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Daniele Torsello, Erik Piatti, Michela Fracasso, Roberto Gerbaldo, Laura Gozzelino, Xiaolei Yi, Xiangzhuo Xing, Zhixiang Shi, Dario Daghero, Gianluca Ghigo. 2024-01-16. Unusually weak irradiation effects in anisotropic iron-based superconductor RbCa2Fe4As4F2. https://doi.org/10.3389/fphy.2023.1336501

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