Superconductivity nearby quantum critical region in hole-doped organic strange metal κ-(ET)<sub>4</sub>Hg<sub>3-δ</sub>Br<sub>8</sub>, δ=11%
Superconductivity nearby quantum critical region in hole-doped organic strange metal κ-(ET)<sub>4</sub>Hg<sub>3-δ</sub>Br<sub>8</sub>, δ=11%
复制标题
空穴掺杂有机奇异金属κ-(ET)<sub>4</sub>Hg<sub>3-δ</sub>Br<sub>8</sub>中量子临界区附近的超导性, δ=11%
DOI：
10.1088/1742-6596/2462/1/012061
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Ishii Y
中科院分区：
文献类型：
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作者：
Sari D P;Kaito M;Someya Y;Widyaiswari U;Watanabe I;Taniguchi H;Ishii Y
空穴掺杂有机超导体κ-（ET）4 Hg 3-δ Br 8，（κ-HgBr），其中δ= 11%，ET=二（亚乙基二硫）四硫富瓦烯，是填补半填充有机体系与掺杂铜酸盐体系之间知识空白的关键。尽管如此，各向同性的三角形晶格的ET二聚体的κ-HgBr是负责的磁化率和超导电性。我们已经测量了κ-HgBr中的零场（ZF）μ子自旋弛豫-旋转（μ+ SR），表明ZF-μ+ SR弛豫速率从10 K左右到0.3 K是温度无关的。这与保持时间反演对称性的超导状态是一致的。在超导温度Tc ~ 4.6（3）K及以上，横场μ+ SR的最大100 Oe时间谱几乎没有变化。这表明面内伦敦穿透深度λ bc大于μm数量级，而我们估计下临界场的下限H c 1为30 Oe，尽管如此，使用另一种几何设置的测量对于确定λ bc的绝对值是必要的。这可能是一个强耦合超导体的迹象。讨论了强耦合非FL金属在几何阻挫作用下形成保留时间反转库珀对的可能机制。
The hole-doped organic superconductor κ-(ET) 4 Hg 3-δ Br 8,(κ-HgBr), where δ= 11% and ET= bis (ethylenedithio) tetrathiafulvalene, has been the key to bridge the knowledge gap between half-filled organics and doped cuprate systems. Nonetheless, the isotropic triangular lattice of ET dimers of κ-HgBr is responsible for the magnetic susceptibility and its superconductivity. We have measured zero-field (ZF) muon spin relaxation-rotation (µ+ SR) in κ-HgBr showing the ZF-µ+ SR relaxation rate from temperature around 10 K down to 0.3 K is temperature-independent. This is consistent with a superconducting state that preserved time-reversal symmetry. There was almost no change in the maximally 100 Oe of transverse-field-µ+ SR time spectra, at 0.3 K and above superconducting temperature, T c~ 4.6 (3) K. This suggests that the in-plane London penetration depth, λ bc, is longer than a μm order, while we estimate the lower limit of the lower critical field, H c1, to be 30 Oe, although, however, the measurement using another geometric setup is necessary to determine the absolute value of λ bc. These could be an indication of a strong-coupling superconductor. A possible mechanism of preserved time-reversal Cooper pairing formation from strong-coupling non-FL metal with geometrical frustration is discussed.