Incommensurate Spin Fluctuations in the Spin-Triplet Superconductor Candidate UTe2
Incommensurate Spin Fluctuations in the Spin-Triplet Superconductor Candidate UTe2
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DOI：
10.1103/physrevlett.125.237003
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发表时间：
2020-12-01
影响因子：
8.6
通讯作者：
Dai, Pengcheng
中科院分区：
文献类型：
--
作者：
Duan, Chunruo;Sasmal, Kalyan;Dai, Pengcheng
自旋三重态超导体由于可以承载拓扑态和马约拉纳费米子而引起广泛的关注，这对量子计算很重要。铀基重费米子超导体UTe2被认为是一种类似于UGe2、URhGe和UCoGe的自旋三重态超导体，其中超导相接近（或共存）铁磁（FM）不稳定性，自旋三重态电子对是由FM自旋涨落驱动的。在这里，我们使用中子散射表明，尽管UTe2在0.3 K以下没有静态磁序，但其在[0，K， L]平面上的磁性在反铁磁有序波矢量附近由不相称的自旋波动主导，并扩展到至少2.6 meV。结合密度泛函理论和动态平均场理论计算了UTe2的电子结构，从而理解了UTe2的主要不适应自旋涨落。
Spin-triplet superconductors are of extensive current interest because they can host topological state and Majorana fermions important for quantum computation. The uranium-based heavy-fermion superconductor UTe2 has been argued as a spin-triplet superconductor similar to UGe2, URhGe, and UCoGe, where the superconducting phase is near (or coexists with) a ferromagnetic (FM) instability and spin-triplet electron pairing is driven by FM spin fluctuations. Here we use neutron scattering to show that, although UTe2 exhibits no static magnetic order down to 0.3 K, its magnetism in the [0, K, L] plane is dominated by incommensurate spin fluctuations near an antiferromagnetic ordering wave vector and extends to at least 2.6 meV. We are able to understand the dominant incommensurate spin fluctuations of UTe2 in terms of its electronic structure calculated using a combined density-functional and dynamic mean-field theory.