arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1908.07396cond-mat.str-el
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重费米子超导体UTe $_2$中的准二维费米面和么正自旋-三重态配对

Quasi-two-dimensional Fermi surfaces and unitary spin-triplet pairing in the heavy fermion superconductor UTe$_2$

Yuanji Xu, Yutao Sheng, Yi-feng Yang

摘要:

本文报道了新发现的重费米子超导体UTe $_2$的第一性原理和强关联计算。我们的分析揭示了它的磁性、电子学和超导性质的三个关键方面:(1)具有强磁阻挫的两条腿的梯形结构,这可能解释了长程序的缺失以及所观察到的磁性和输运各向异性;(2)由两个独立的电子和空穴圆柱体组成的准二维费米面,其嵌套性质与UGe $_2$相似,这可能潜在地促进磁波动并有助于增强自旋-三重态配对;(3)在零场处强自旋-轨道耦合的幺正自旋-三重态配对状态,与先前的非幺正配对的信念相反,点节点可能沿着$k_x$方向位于较重的空穴费米表面上。我们提出的方案与最新的热导率测量结果非常吻合,并为理解UTe $_2$的特殊磁性和超导性质提供了基础。

英文摘要:

We report first-principles and strongly-correlated calculations of the newly-discovered heavy fermion superconductor UTe$_2$. Our analyses reveal three key aspects of its magnetic, electronic, and superconducting properties, that include: (1) a two-leg ladder-type structure with strong magnetic frustrations, which might explain the absence of long-range orders and the observed magnetic and transport anisotropy; (2) quasi-two-dimensional Fermi surfaces composed of two separate electron and hole cylinders with similar nesting properties as in UGe$_2$, which may potentially promote magnetic fluctuations and help to enhance the spin-triplet pairing; (3) a unitary spin-triplet pairing state of strong spin-orbit coupling at zero field, with point nodes presumably on the heavier hole Fermi surface along the $k_x$-direction, in contrast to the previous belief of non-unitary pairing. Our proposed scenario is in excellent agreement with latest thermal conductivity measurement and provides a basis for understanding the peculiar magnetic and superconducting properties of UTe$_2$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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