Omnidirectional Measurements of Angle-Resolved Heat Capacity for Complete Detection of Superconducting Gap Structure in the Heavy-Fermion Antiferromagnet UPd2Al3
Omnidirectional Measurements of Angle-Resolved Heat Capacity for Complete Detection of Superconducting Gap Structure in the Heavy-Fermion Antiferromagnet UPd2Al3
复制标题
全方位测量角分辨热容，全面检测重费米子反铁磁体 UPd2Al3 中的超导间隙结构
DOI：
10.1103/physrevlett.117.037001
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
and D. Aoki
中科院分区：
文献类型：
--
作者：
Y. Shimizu;S. Kittaka;T. Sakakibara;Y. Tsutsumi;T. Nomoto;H. Ikeda;K. Machida;Y. Homma;and D. Aoki
本文用高质量单晶在旋转磁场下的热容（）测量方法研究了准粒子激发。对于两个六方晶轴，在低温下场依赖性表现出类似的行为，即，（轴）和（轴），这表明存在的节点准粒子激发从重带。在低温下，在0.5T以下，极角（）的依赖性出现极大值，并伴随着双重对称振荡，在中间场（）中，在离轴30° ~ 60 °附近发现了异常的肩峰或峰形异常。这些行为不完全来自超导节结的准粒子激发，并且可以通过假设带隙差距与水平直线节对称的理论计算成功地再现。我们展示了整个角度分辨热容测量作为一种新的光谱方法节点间隙的确定，它可以应用于其他外来超导体。
Quasiparticle excitations inwere studied by means of heat-capacity () measurements under rotating magnetic fields using a high-quality single crystal. The field dependence shows-like behavior at low temperatures for both two hexagonal crystal axes, i.e.,(axis) and(axis), suggesting the presence of nodal quasiparticle excitations from heavy bands. At low temperatures, the polar-angle () dependence ofexhibits a maximum alongwith a twofold symmetric oscillation below 0.5 T, and an unusual shoulder or hump anomaly has been found around 30°–60° from theaxis inat intermediate fields (). These behaviors inpurely come from the superconducting nodal quasiparticle excitations, and can be successfully reproduced by theoretical calculations assuming the gap symmetry with a horizontal linear line node. We demonstrate the whole angle-resolved heat-capacity measurements done here as a novel spectroscopic method for nodal gap determination, which can be applied to other exotic superconductors.