Nonunitary triplet superconductivity tuned by field-controlled magnetization: URhGe, UCoGe, and UTe2
Nonunitary triplet superconductivity tuned by field-controlled magnetization: URhGe, UCoGe, and UTe2
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通过场控磁化调节的非酉三重态超导：URhGe、UCoGe 和 UTe2
DOI：
10.1103/physrevb.104.014514
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Kazushige Machida
中科院分区：
文献类型：
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作者：
Kazushige Machida
本文报道了对铁磁超导体URhGe和UCoGe的理论研究，并确定了偶态为时间反转对称性破缺的非幺正自旋三重态，类似于超流体相。用同样的方法分析了最近发现的一种几乎铁磁性的超导体。通过对它们特殊的上临界场形状的研究，表明这三种化合物的配对对称性可以通过它们在外加场下的磁化曲线来调节。这导致在磁硬轴方向上观察到URhGe的重入，UCoGe的s形和l形。双手性形式的识别自然使我们能够理解(1)与压力下观察到的相的多相，(2)与一阶超磁转变相关的离轴方向的增强重入性，以及(3)沿磁易轴方向的Weyl点节点。这三种化合物都是拓扑结构丰富的固态材料，值得进一步研究。
We report on a theoretical study on ferromagnetic superconductors URhGe and UCoGe and identify the pairing state as a nonunitary spin-triplet one with time-reversal symmetry broken, analogous to the superfluidphase. A recently found superconductorwith almost ferromagnetism is analyzed by the same manner. Through investigating their peculiar upper critical fieldshapes, it is shown that the pairing symmetry realized in all three compounds can be tuned by their magnetization curves under applied fields. This leads to the reentrantin URhGe, an S-shaped in UCoGe and an L-shapedinobserved for the magnetic hard-axis direction. The identification with double chiral forminnaturally enables us to understand (1) multiple phases with, andphases observed under pressure, (2) the enhanced reentrantfor the off-axis direction associated with first-order metamagnetic transition, and (3) Weyl point nodes oriented along the magnetic easyaxis. All three compounds are found to be topologically rich solid-state materials worth further investigation.