Nodal versus nodeless behaviors of the order parameters of LiFeP and LiFeAs superconductors from magnetic penetration-depth measurements.
Nodal versus nodeless behaviors of the order parameters of LiFeP and LiFeAs superconductors from magnetic penetration-depth measurements.
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DOI：
10.1103/physrevlett.108.047003
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发表时间：
2011-07
影响因子：
8.6
通讯作者：
K. Hashimoto;S. Kasahara;R. Katsumata;Y. Mizukami;M. Yamashita;H. Ikeda;T. Terashima;A. Carrington-A.-Ca
中科院分区：
文献类型：
--
作者：
K. Hashimoto;S. Kasahara;R. Katsumata;Y. Mizukami;M. Yamashita;H. Ikeda;T. Terashima;A. Carrington-A.-Ca
对干净的 LiFeAs 和 LiFeP 超导体单晶的磁穿透深度 λ 进行高精度测量，揭示了不同的行为。在 LiFeAs 中，低温 λ(T) 显示出平坦的依赖性，表明完全带隙状态，这与之前的研究一致。相比之下，LiFeP 表现出超流体密度无穷大 λ(-2) 的 T 线性依赖性，表明节点超导有序参数。对 1111、122 和 111 族铁-磷元素超导体中的准粒子激发进行的系统比较表明，当磷元素距离铁平面的高度降低到~1.33 Å 的阈值以下时，会引发节点态。
High-precision measurements of magnetic penetration depth λ in clean single crystals of LiFeAs and LiFeP superconductors reveal contrasting behaviors. In LiFeAs the low-temperature λ(T) shows a flat dependence indicative of a fully gapped state, which is consistent with previous studies. In contrast, LiFeP exhibits a T-linear dependence of superfluid density infinity λ(-2), indicating a nodal superconducting order parameter. A systematic comparison of quasiparticle excitations in the 1111, 122, and 111 families of iron-pnictide superconductors implies that the nodal state is induced when the pnictogen height from the iron plane decreases below a threshold value of ~1.33 Å.