NMR evidence of strongly correlated superconductivity in LiFeAs: Tuning toward a spin-density-wave ordering
NMR evidence of strongly correlated superconductivity in LiFeAs: Tuning toward a spin-density-wave ordering
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DOI：
10.1103/physrevb.82.180501
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发表时间：
2010-08
影响因子：
3.7
通讯作者：
L. Ma;J. Zhang;G. Chen;Weiqiang Yu
中科院分区：
文献类型：
--
作者：
L. Ma;J. Zhang;G. Chen;Weiqiang Yu
在这篇快速通讯中，我们报道了LiFeAs单晶的NMR研究结果。我们发现了一个强有力的证据，低温自旋波动，通过改变样品制备条件，系统可以调整到自旋密度波（SDW）量子临界点。间隙Li（2）离子的检测，可能位于四面体孔中，表明非化学计量比和/或晶格缺陷可能解释了LiFeAs中SDW有序的缺失。这些事实表明LiFeAs是一个强关联体系，其超导电性很可能来源于SDW涨落。
In this Rapid Communication, we reported the results of NMR study on LiFeAs single crystals. We find a strong evidence of the low-temperature spin fluctuations; by changing sample preparation conditions, the system can be tuned toward a spin-density-wave (SDW) quantum-critical point. The detection of an interstitial Li(2) ion, possibly locating in the tetrahedral hole, suggests that the off-stoichiometry and/or lattice defect can probably account for the absence of the SDW ordering in LiFeAs. These facts show that LiFeAs is a strongly correlated system and the superconductivity is likely originated from the SDW fluctuations.