Conventional s-Wave Superconductivity in BiS2-Based NdO0.71F0.29BiS2 Revealed by Thermal Transport Measurements
Conventional s-Wave Superconductivity in BiS2-Based NdO0.71F0.29BiS2 Revealed by Thermal Transport Measurements
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DOI：
10.7566/jpsj.85.073707
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发表时间：
2016-01
影响因子：
1.7
通讯作者：
T. Yamashita;Y. Tokiwa;D. Terazawa;M. Nagao;S. Watauchi;I. Tanaka;T. Terashima;Y. Matsuda
中科院分区：
文献类型：
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作者：
T. Yamashita;Y. Tokiwa;D. Terazawa;M. Nagao;S. Watauchi;I. Tanaka;T. Terashima;Y. Matsuda
为了研究基于bis2的层状化合物NdO0.71F0.29BiS2 （Tc = 5 K）的超导间隙结构，我们测量了热传导系数κ，这是低能准粒子光谱的敏感探针。在没有磁场的情况下，T→0时导热系数κ0/T的剩余线性项很小，这表明在节点超导体中不存在预期的剩余正常流体。此外，在大范围的涡旋状态下，外加磁场对热导率几乎没有影响，表明不存在多普勒位移准粒子。这些结果证明NdO0.71F0.29BiS2是一个全间隙超导体。所获得的间隙结构以及超导性对杂质的鲁棒性表明，NdO0.71F0.29BiS2中存在常规s波超导状态。
To study the superconducting gap structure of BiS2-based layered compound NdO0.71F0.29BiS2 (Tc = 5 K), we measured the thermal conductivity κ, which is a sensitive probe of low-energy quasiparticle spectrum. In the absence of a magnetic field, residual linear term in the thermal conductivity κ0/T at T → 0 is vanishingly small, indicating that the residual normal fluid, which is expected for nodal superconductors, is absent. Moreover, the applied magnetic field hardly affects thermal conductivity in wide range of the vortex state, indicating the absence of Doppler shifted quasiparticles. These results provide evidence that NdO0.71F0.29BiS2 is a fully gapped superconductor. The obtained gap structure, along with the robustness of the superconductivity against the impurity, suggest a conventional s-wave superconducting state in NdO0.71F0.29BiS2.