Spin dynamics in iron-based layered superconductor (La0.87Ca0.13)FePO revealed by 31P and 139La NMR studies
Spin dynamics in iron-based layered superconductor (La0.87Ca0.13)FePO revealed by 31P and 139La NMR studies
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DOI：
10.1103/physrevlett.101.077006
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发表时间：
2008-08-15
影响因子：
8.6
通讯作者：
Hosono, Hideo
中科院分区：
文献类型：
--
作者：
Nakai, Yusuke;Ishida, Kenji;Hosono, Hideo
本文报道了（La（0.87）Ca（0.13））FePO的（31）P和（139）La NMR研究。在正常状态下，Knight位移和自旋-晶格弛豫速率除以T（1/T（1）T）表明，在30 K以下出现了具有中等铁磁涨落的费米液态。从（31）P和（139）La的1/T（1）T，提出了准二维电子结构，其中FeP层比LaO层导电性好。在超导（SC）状态下，虽然观察到明显的迈斯纳信号，但1/T（1）T在T（c）以下增加，与由于SC能隙的打开而减少1/T（1）T相反，这表明在SC状态下发展了新的低能自旋动力学。
We report (31)P and (139)La NMR studies of (La(0.87)Ca(0.13))FePO, which is a family member of the recently discovered superconductor LaFeAs(O(1-x)F(x)). In the normal state, Knight shift and nuclear spin-lattice relaxation rate divided by T (1/T(1)T) show that a Fermi-liquid state with moderate ferromagnetic fluctuations emerges below 30 K. From 1/T(1)T of (31)P and (139)La, a quasi-two- dimensional electronic structure is suggested, in which the FeP layer is more conductive than the LaO layer. In the superconducting (SC) state, although a clear Meissner signal was observed, 1/T(1)T increases below T(c), in contrast to a decrease of 1/T(1)T due to the opening of a SC gap, suggesting that novel low-energy spin dynamics develop in the SC state.