Wang Jiajun, Gao Mengyu, Wu Ziming, Wang Yunong, Han Wenbo, Li Dongyan, Shi Zhenzhong
School of Physical Science and Technology, Soochow University, Suzhou 215006, People's Republic of China.
Institute for Advanced Study, Soochow University, Suzhou 215006, People's Republic of China.
J Phys Condens Matter. 2025 Jun 18;37(25). doi: 10.1088/1361-648X/ade2af.
Misfit layered compounds based on transition metal dichalcogenides (TMDs) provide a rich platform for exploring emergent quantum phases, such as superconductivity and charge density wave (CDW) order. While many parent TMD compounds host both superconductivity and CDW, their misfit analogs often preserve only superconductivity. In this work, we present a comprehensive investigation of the misfit compound(SnS)1.15TaS2, a promising candidate for exhibiting both Ising-like superconductivity and a weak CDW. Through electrical transport and thermoelectric measurements, we find that the in-plane upper critical fieldHc2(T=0)significantly exceeds the Pauli paramagnetic limit, consistent with Ising superconductivity. Hall measurements reveal a notable reduction in carrier density below 50 K, suggesting the onset of CDW order. Seebeck and Hall data further indicate dominant n-type carriers, and suggest that while charge transfer from the SnS layer is minimal, cross-substitutional doping between Sn and Ta atoms may play an important role in modifying the Fermi surface. Our findings demonstrate that charge transfer predominantly influences CDW formation, whereas Ising superconductivity is robust against it, offering new insights into the interplay between structural motifs and electronic phases in misfit TMD materials.
基于过渡金属二硫属化物（TMDs）的失配层状化合物为探索新兴量子相提供了一个丰富的平台，如超导性和电荷密度波（CDW）序。虽然许多母体TMD化合物同时具有超导性和CDW，但它们的失配类似物通常仅保留超导性。在这项工作中，我们对失配化合物(SnS)1.15TaS2进行了全面研究，它是一种有望同时展现类伊辛超导性和弱CDW的候选材料。通过电输运和热电测量，我们发现面内上临界场Hc2(T=0)显著超过泡利顺磁极限，这与伊辛超导性一致。霍尔测量表明，在50 K以下载流子密度显著降低，这表明CDW序开始出现。塞贝克和霍尔数据进一步表明主要是n型载流子，并表明虽然从SnS层的电荷转移最小，但Sn和Ta原子之间的交叉替代掺杂可能在修改费米面方面起重要作用。我们的研究结果表明，电荷转移主要影响CDW的形成，而伊辛超导性对此具有鲁棒性，这为失配TMD材料中结构基序与电子相之间的相互作用提供了新的见解。
