Ferromagnetic Spin Fluctuation and Unconventional Superconductivity in Rb2Cr3As3 Revealed by 75As NMR and NQR.
Ferromagnetic Spin Fluctuation and Unconventional Superconductivity in Rb2Cr3As3 Revealed by 75As NMR and NQR.
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DOI：
10.1103/physrevlett.115.147002
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发表时间：
2015-08
影响因子：
8.6
通讯作者：
J. Yang;Zhoufei Tang;G. Cao;G. Zheng;G. Zheng
中科院分区：
文献类型：
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作者：
J. Yang;Zhoufei Tang;G. Cao;G. Zheng;G. Zheng
本文报道了具有准一维晶体结构的超导体Rb（2）Cr（3）As（3）的核磁共振（NMR）和核四极共振（NQR）研究。在T = 100 K以下，自旋-晶格弛豫速率（1/T（1））除以温度，1/T（1）T，在冷却到T（c）=4.8 K时增加，显示出类似居里-外斯的温度依赖性。奈特位移也随着温度的降低而增加。这些结果表明铁磁自旋涨落。在超导状态下，1/T（1）在T（c）以下迅速下降，没有Hebel-Slichter峰，并在T ~ 3 K以下遵循T（5）变化，这表明在差距函数中具有点节点的非常规超导性。
We report (75)As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) studies on the superconductor Rb(2)Cr(3)As(3) with a quasi-one-dimensional crystal structure. Below T∼100 K, the spin-lattice relaxation rate (1/T(1)) divided by temperature, 1/T(1)T, increases upon cooling down to T(c)=4.8 K, showing a Curie-Weiss-like temperature dependence. The Knight shift also increases with decreasing temperature. These results suggest ferromagnetic spin fluctuation. In the superconducting state, 1/T(1) decreases rapidly below T(c) without a Hebel-Slichter peak, and follows a T(5) variation below T∼3 K, which points to unconventional superconductivity with point nodes in the gap function.