Zhi H Z, Imai T, Ning F L, Bao Jin-Ke, Cao Guang-Han
Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S4M1, Canada.
Canadian Institute for Advanced Research, Toronto, Ontario M5G1Z8, Canada.
Phys Rev Lett. 2015 Apr 10;114(14):147004. doi: 10.1103/PhysRevLett.114.147004. Epub 2015 Apr 9.
We report ^{75}As NMR measurements on the new quasi-one-dimensional superconductor K_{2}Cr_{3}As_{3} (T_{c}∼6.1 K) [J. K. Bao et al., Phys. Rev. X 5, 011013 (2015)]. We found evidence for strong enhancement of Cr spin fluctuations above T_{c} in the [Cr_{3}As_{3}]{∞} double-walled subnanotubes based on the nuclear spin-lattice relaxation rate 1/T{1}. The power-law temperature dependence, 1/T_{1}T∼T^{-γ} (γ∼0.25), is consistent with the Tomonaga-Luttinger liquid. Moreover, absence of the Hebel-Slichter coherence peak of 1/T_{1} just below T_{c} suggests an unconventional nature of superconductivity.
我们报告了对新型准一维超导体(K_{2}Cr_{3}As_{3})（(T_{c}\sim6.1K)）[J.K. Bao等人，《物理评论X》5，011013（2015年）]的(^{75}As)核磁共振测量结果。基于核自旋 - 晶格弛豫率(1/T_{1})，我们发现了在([Cr_{3}As_{3}]{\infty})双壁亚纳米管中，高于(T{c})时(Cr)自旋涨落强烈增强的证据。幂律温度依赖性(1/T_{1}T\sim T^{-\gamma})（(\gamma\sim0.25)）与汤川 - 卢廷格液体一致。此外，在(T_{c})稍下方不存在(1/T_{1})的海贝尔 - 施利希特相干峰，这表明超导具有非常规性质。
