Enhancement of superconducting transition temperature due to the strong antiferromagnetic spin fluctuations in the noncentrosymmetric heavy-fermion superconductor CeIrSi3: A 29Si NMR study under pressure.
Enhancement of superconducting transition temperature due to the strong antiferromagnetic spin fluctuations in the noncentrosymmetric heavy-fermion superconductor CeIrSi3: A 29Si NMR study under pressure.
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DOI：
10.1103/physrevlett.100.107003
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发表时间：
2008-01
影响因子：
8.6
通讯作者：
H. Mukuda;T. Fujii;T. Ohara;A. Harada;M. Yashima;Y. Kitaoka;Y. Okuda;R. Settai;Y. Ōnuki
中科院分区：
文献类型：
--
作者：
H. Mukuda;T. Fujii;T. Ohara;A. Harada;M. Yashima;Y. Kitaoka;Y. Okuda;R. Settai;Y. Ōnuki
利用（29）Si NMR研究了反铁磁（AFM）重费米子化合物CeIrSi（3）的压力诱导超导性。在P = 2.7- 2.8GPa的SC态中，低于T（c）的核自旋晶格弛豫率1/T（1）的温度（T）依赖性表现出T（3）行为，而没有任何相干峰，揭示了SC带隙中存在线节点。在正常状态下，1/T（1）遵循平方根T型行为，表明SC出现在非费米液体状态下，由AFM自旋涨落在量子临界点附近增强主导。CeIrSi（3）中的最大T（c）在Ce基重费米子超导体中相对较高的原因可能是存在较强的AFM自旋涨落。我们讨论了与其他Ce基重费米子超导体的比较。
We report a (29)Si NMR study on the pressure-induced superconductivity (SC) in an antiferromagnetic (AFM) heavy-fermion compound CeIrSi(3) without inversion symmetry. In the SC state at P = 2.7-2.8 GPa, the temperature (T) dependence of the nuclear-spin lattice relaxation rate 1/T(1) below T(c) exhibits a T(3) behavior without any coherence peak just below T(c), revealing the presence of line nodes in the SC gap. In the normal state, 1/T(1) follows a square root T-like behavior, suggesting that the SC emerges under the non-Fermi-liquid state dominated by AFM spin fluctuations enhanced around a quantum critical point. The reason why the maximum T(c) in CeIrSi(3) is relatively high among the Ce-based heavy-fermion superconductors may be the existence of the strong AFM spin fluctuations. We discuss the comparison with the other Ce-based heavy-fermion superconductors.