铁取代4d过渡金属硫化物中的涌现磁性、重电子与压力诱导的重入超导电性
Emergent magnetism, heavy electrons and pressure-induced reentrant superconductivity in the iron substituted 4d transition-metal sulfides
- Zhejiang University of Technology（浙江工业大学）
- Fudan University（复旦大学）
- Qufu Normal University（曲阜师范大学）
- Nanjing University of Posts and Telecommunications（南京邮电大学）
- Suzhou University of Technology（苏州科技大学）
- Hangzhou Dianzi University（杭州电子科技大学）
- National Taiwan Normal University（台湾师范大学）
- Academia Sinica（中央研究院）
- Zhejiang University（浙江大学）
- Ningbo University（宁波大学）
- Hangzhou Normal University（杭州师范大学）
- Shanghai Jiao Tong University（上海交通大学）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本文报道铁取代的Rh17S15超导体中涌现铁磁性、重电子行为及压力诱导的重入超导电性，表明其超导可能由自旋涨落介导而非常规。
中文摘要 AI 辅助
从磁性态中或磁性态附近涌现的超导电性通常被认为是由自旋涨落所介导，因此超出了传统电-声子耦合的BCS框架范畴。在此，我们报道了d电子硫化物Rh17S15超导体中出现的新型铁磁性，其特征是由平坦拓扑带和多体关联引起的增强的索末菲系数γ。我们进一步证明，通过在Rh位点进行Fe取代可以调控该铁磁性，导致由竞争的铁磁和反铁磁交换相互作用所诱导的自旋玻璃基态。Fe掺杂使得γ和电子有效质量均进一步增强。在Rh17-xFexS15中掺杂水平为x=0.67时，γ达到312 mJ mol-1K-2，仅次于文献中充分记载的d电子重费米子材料LiV2O4。此外，在施加压力时，超导电性首先被抑制；然而在高压下，我们在原始样品和Fe掺杂样品中都观察到了重入超导电性。我们的结果不仅展示了这些无阻挫、基于d电子的超导体中不寻常的磁性态和可能的重费米子特征，而且表明该体系中的超导电性很可能由内禀自旋涨落所介导，因此可能是非常规的。
英文摘要
Superconductivity emerging from or in the vicinity of magnetic states is generally considered to be mediated by spin fluctuations and thus lies beyond the scope of conventional electron-phonon coupled BCS framework. Here we report the emergence of novel ferromagnetism in the d-electron rhodium sulfide Rh17S15 superconductor, characterized by an enhanced Sommerfeld coefficient γ arising from the flat topological band and many-body correlations. We further demonstrate that the ferromagnetism can be tuned via Fe substitution at the Rh sites, leading to a spin glass ground state induced by the competing ferromagnetic and antiferromagnetic exchange interactions. Fe doping results in a further enhancement of both the γ and electron effective masses. At a doping level of x = 0.67 in Rh17-xFexS15, γ reaches 312 mJ mol-1K-2, second only to the well-documented d-electron heavy-fermion material LiV2O4. Furthermore, upon applying pressure, superconductivity is first suppressed; under high pressures, however, we observe the reentrant superconductivity in both pristine and Fe-doped samples. Our results not only demonstrate the unusual magnetic states and possible heavy-fermion features in these frustration-free, d-based superconductors, but also suggest that the superconductivity in this system is likely mediated by the intrinsic spin fluctuations and may thus be unconventional.
