Multiband superconductivity of heavy electrons in a TlNi2Se2 single crystal.
Multiband superconductivity of heavy electrons in a TlNi2Se2 single crystal.
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DOI：
10.1103/physrevlett.111.207001
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发表时间：
2013-03
影响因子：
8.6
通讯作者：
Hangdong Wang;C. Dong;Qianhui Mao;R. Khan;Xi Zhou;Chenxia Li;Bin Chen;Jinhu Yang;Qiping Su-Qipi
中科院分区：
文献类型：
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作者：
Hangdong Wang;C. Dong;Qianhui Mao;R. Khan;Xi Zhou;Chenxia Li;Bin Chen;Jinhu Yang;Qiping Su-Qipi
我们首次观察到 T(C)=3.7 K 时 TlNi2Se2 中的超导性，根据常态电子比热和上临界场 H(C2)(T) 推断，它似乎涉及有效质量为 m*=(14-20)m(b) 的重电子。我们发现超导态的零场电子比热数据C(es)(T) (0.5 K≤T<3.7 K)可以用双能隙BCS模型拟合，表明TlNi2Se2似乎是多能带超导体，这与同构KNi2S2的能带计算一致。还发现混合态电子比热系数γN(H)表现出H(1/2)行为，这被认为是d波超导体的共同特征。 TlNi2Se2作为具有重电子超导性的d电子系统，可能成为铜基或铁基超导体与传统重费米子超导体之间的桥梁。
We have made the first observation of superconductivity in TlNi2Se2 at T(C)=3.7 K, and it appears to involve heavy electrons with an effective mass m*=(14-20)m(b), as inferred from the normal-state electronic specific heat and the upper critical field, H(C2)(T). We found that the zero-field electronic specific-heat data, C(es)(T) (0.5 K≤T<3.7 K) in the superconducting state can be fitted with a two-gap BCS model, indicating that TlNi2Se2 seems to be a multiband superconductor, which is consistent with the band calculation for the isostructural KNi2S2. It is also found that the electronic specific-heat coefficient in the mixed state γN(H) exhibits a H(1/2) behavior, which is considered as a common feature of the d-wave superconductors. TlNi2Se2, as a d-electron system with heavy electron superconductivity, may be a bridge between cuprate- or iron-based and conventional heavy-fermion superconductors.