Disorder-Driven Transition from s± to s+ + Superconducting Order Parameter in Proton Irradiated Ba(Fe1-xRhx)2As2 Single Crystals
Disorder-Driven Transition from s± to s+ + Superconducting Order Parameter in Proton Irradiated Ba(Fe1-xRhx)2As2 Single Crystals
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DOI：
10.1103/physrevlett.121.107001
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发表时间：
2018-09-04
影响因子：
8.6
通讯作者：
Canfield, P. C.
中科院分区：
文献类型：
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作者：
Ghigo, G.;Torsello, D.;Canfield, P. C.
利用微波测量的伦敦穿透深度和临界温度T-c表明，在最佳掺杂的Ba（Fe 1-xRhx）（2）As-2单晶中，无序由3.5 MeV质子辐照引起，有序参数对称性从s（+/-）转变为s（++）。这种转变的迹象，理论上预测[V. D。Efremov等人，Phys. Rev. B 84，180512（R）（2011）]，发现作为伦敦穿透深度的低温值的下降和几乎与无序无关的超导T-c。我们展示了如何这些实验观察可以描述的多频带Eliashberg计算中的影响，占在一个合适的方式混乱。为了这个目的，一个有效的两个波段的方法，使我们能够治疗的范围内的玻恩近似和酉限制之间的混乱。
Microwave measurements of the London penetration depth and critical temperature T-c were used to show evidence of a disordered-driven transition from s(+/-) to s(++) order parameter symmetry in optimally doped Ba(Fe1-xRhx)(2) As-2 single crystals, where disorder was induced by means of 3.5 MeV proton irradiation. Signatures of such a transition, as theoretically predicted [V.D. Efremov et al., Phys. Rev. B 84, 180512(R) (2011)], are found as a drop in the low-temperature values of the London penetration depth and a virtually disorder-independent superconducting T-c. We show how these experimental observations can be described by multiband Eliashberg calculations in which the effect of disorder is accounted for in a suitable way. To this aim, an effective two-band approach is adopted, allowing us to treat disorder in a range between the Born approximation and the unitary limit.