Horie R, Horigane K, Nishiyama S, Akimitsu M, Kobayashi K, Onari S, Kambe T, Kubozono Y, Akimitsu J
Research Institute for Interdisciplinary Science, Okayama University, Okayama, Japan.
J Phys Condens Matter. 2020 Apr 24;32(17):175703. doi: 10.1088/1361-648X/ab6a2e.
We report here the superconducting properties of a Laves phase superconductor SrIr, which has a cubic MgCu structure. SrIr is a type-II superconductor, with a T of 5.9 K. The estimated superconducting parameters of lower critical field µ H and upper critical field µ H , coherence length ξ(0), penetration depth λ(0) and Ginzburg-Landau (GL) parameter κ(0) are approximately µ H = 101 Oe, µ H (0) = 5.9 T, ξ(0) = 7.47 nm, λ(0) = 237 nm, and κ(0) = 31.7, respectively. The specific-heat data indicate that SrIr is a strong-coupling superconductor because the value of ΔC/γT is approximately 1.71, which is larger than the value of 1.43 that is expected from the BCS theory. The physical properties obtained in this study are explained well by theoretical calculations including spin-orbit coupling (SOC). This result indicates that the physical properties of SrIr are strongly affected by the presence of SOC.
我们在此报告具有立方MgCu结构的拉夫斯相超导体SrIr的超导特性。SrIr是一种II型超导体，其转变温度(T_c)为5.9 K。估计的下临界场(\mu_0H_{c1})、上临界场(\mu_0H_{c2})、相干长度(\xi(0))、穿透深度(\lambda(0))和金兹堡 - 朗道（GL）参数(\kappa(0))分别约为(\mu_0H_{c1}=101) Oe、(\mu_0H_{c2}(0)=5.9) T、(\xi(0)=7.47) nm、(\lambda(0)=237) nm以及(\kappa(0)=31.7)。比热数据表明SrIr是一种强耦合超导体，因为(\Delta C/\gamma T)的值约为1.71，大于BCS理论预期的1.43值。本研究中获得的物理性质通过包括自旋 - 轨道耦合（SOC）的理论计算得到了很好的解释。这一结果表明SrIr的物理性质受到SOC存在的强烈影响。
