NMR Study on a Pnictide Superconductor LaFeAsO1−xHx in a H-Overdoped Regime: Revival of Antiferromagnetic Fluctuations
NMR Study on a Pnictide Superconductor LaFeAsO1−xHx in a H-Overdoped Regime: Revival of Antiferromagnetic Fluctuations
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DOI：
10.1007/s10948-013-2413-z
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发表时间：
2014-04
影响因子：
1.8
通讯作者：
N. Fujiwara;S. Iimura;S. Matsuishi;H. Hosono;Y. Yamakawa;H. Kontani
中科院分区：
文献类型：
--
作者：
N. Fujiwara;S. Iimura;S. Matsuishi;H. Hosono;Y. Yamakawa;H. Kontani
电子掺杂的高TcpNictide化合物LaFeAsO1−xHx最近被认为在相图中具有双超导(SC)穹顶。我们在氢过掺杂区域进行了核磁共振测量，在微观水平上研究了第二个SC穹顶。我们意外地发现，对于58和62.5%的氢掺杂样品，75As和1H谱的线宽在低温下都变宽了，这表明在重掺氢的区域，反铁磁(AF)有序又回来了。这一发现本身是罕见的，因为过量的载流子掺杂往往会导致强关联电子系统中的费米-液体行为。我们证明了新的AF有序起源于电子口袋之间的嵌套。
An electron-doped high-Tcpnictide LaFeAsO1−xHxis recently known for having double superconducting (SC) domes in the phase diagram. We have performed nuclear magnetic resonance (NMR) measurements in an H-overdoped regime to investigate the second SC dome on a microscopic level. We unexpectedly discovered that the linewidths of both75As and1H spectra broaden at low temperatures for the 58 and 62.5 % H-doped samples, indicating that the antiferromagnetic (AF) ordering returns in the heavily H-doped regime. The finding itself is rare because an excess carrier doping tends to cause Fermi-liquid behavior in strongly correlated electron systems. We demonstrate that the new AF ordering originates from the nesting between electron pockets.