论文标题
单独调整nematicity和自旋波动以揭示FESE超导性的起源
Separate tuning of nematicity and spin fluctuations to unravel the origin of superconductivity in FeSe
论文作者
论文摘要
轨道和自旋程度的自由度的相互作用是许多冷凝物现象的基本特征，包括高温超导性，量子自旋液体和拓扑半学。在基于铁的超导体（FESC）中，这会导致超导性在另外两个不稳定性附近出现：列和磁性。揭示了列表秩序，自旋波动和超导性之间的相互关系是FESC研究的主要挑战，但仍然存在争议。在这里，通过对fESE单晶进行77SE核磁共振（NMR）测量，用钴和硫作为控制参数的掺杂，我们证明了超导过渡温度TC的成比例与旋转波动的强度相比，同时却独立于nematic Trivertion Temportion温度TNEM。因此，我们的观察结果直接意味着FESE中的超导性基本上是由中间耦合方案中的自旋波动驱动的，而列的波动对TC具有边际影响。
The interplay of orbital and spin degrees of freedom is the fundamental characteristic in numerous condensed matter phenomena, including high temperature superconductivity, quantum spin liquids, and topological semimetals. In iron-based superconductors (FeSCs), this causes superconductivity to emerge in the vicinity of two other instabilities: nematic and magnetic. Unveiling the mutual relationship among nematic order, spin fluctuations, and superconductivity has been a major challenge for research in FeSCs, but it is still controversial. Here, by carrying out 77Se nuclear magnetic resonance (NMR) measurements on FeSe single crystals, doped by cobalt and sulfur that serve as control parameters, we demonstrate that the superconducting transition temperature Tc increases in proportion to the strength of spin fluctuations, while it is independent of the nematic transition temperature Tnem. Our observation therefore directly implies that superconductivity in FeSe is essentially driven by spin fluctuations in the intermediate coupling regime, while nematic fluctuations have a marginal impact on Tc.
