Superconducting pairs with extreme uniaxial anisotropy in URu2Si2.
Superconducting pairs with extreme uniaxial anisotropy in URu2Si2.
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URu2Si2 中具有极端单轴各向异性的超导对。
DOI：
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发表时间：
2012
影响因子：
8.6
通讯作者：
E. Bauer
中科院分区：
文献类型：
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作者：
M. Altarawneh;N. Harrison;Gang Li;L. Balicas;P. Tobash;F. Ronning;E. Bauer
我们报道了在高质量的URu(2)Si(2)单晶中超导临界上场的磁场取向相关测量，并发现从泡利极限估计的有效g因子在定量和自旋磁化率的极端各向异性（≈10(3)）中与量子振荡实验的结果非常吻合。而不是严格的流动或纯粹的局部f电子图像适用，后者表明，在URu(2)Si(2)中受配对的准粒子是“复合重费米子”，由导电电子和具有保护Ising行为的局部矩之间的束缚态形成。极端各向异性表明，非克莱默双重态局域磁自由度有利于局域配对机制。
We report magnetic field orientation-dependent measurements of the superconducting upper critical field in high quality single crystals of URu(2)Si(2) and find the effective g factor estimated from the Pauli limit to agree remarkably well with that found in quantum oscillation experiments, both quantitatively and in the extreme anisotropy (≈10(3)) of the spin susceptibility. Rather than a strictly itinerant or purely local f-electron picture being applicable, the latter suggests the quasiparticles subject to pairing in URu(2)Si(2) to be "composite heavy fermions" formed from bound states between conduction electrons and local moments with a protected Ising behavior. Non-Kramers doublet local magnetic degrees of freedom suggested by the extreme anisotropy favor a local pairing mechanism.