Fang Yuqiang, Pan Jie, Zhang Dongqin, Wang Dong, Hirose Hishiro T, Terashima Taichi, Uji Shinya, Yuan Yonghao, Li Wei, Tian Zhen, Xue Jiamin, Ma Yonghui, Zhao Wei, Xue Qikun, Mu Gang, Zhang Haijun, Huang Fuqiang
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, 200050, P. R. China.
State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
Adv Mater. 2019 Jul;31(30):e1901942. doi: 10.1002/adma.201901942. Epub 2019 Jun 3.
Recently the metastable 1T'-type VIB-group transition metal dichalcogenides (TMDs) have attracted extensive attention due to their rich and intriguing physical properties, including superconductivity, valleytronics physics, and topological physics. Here, a new layered WS dubbed "2M" WS , is constructed from 1T' WS monolayers, is synthesized. Its phase is defined as 2M based on the number of layers in each unit cell and the subordinate crystallographic system. Intrinsic superconductivity is observed in 2M WS with a transition temperature T of 8.8 K, which is the highest among TMDs not subject to any fine-tuning process. Furthermore, the electronic structure of 2M WS is found by Shubnikov-de Haas oscillations and first-principles calculations to have a strong anisotropy. In addition, topological surface states with a single Dirac cone, protected by topological invariant Z , are predicted through first-principles calculations. These findings reveal that the new 2M WS might be an interesting topological superconductor candidate from the VIB-group transition metal dichalcogenides.
最近，亚稳的1T'-型VIB族过渡金属二硫属化物（TMDs）因其丰富而有趣的物理性质，包括超导性、谷电子学物理和拓扑物理，而受到广泛关注。在此，一种名为“2M”WS₂的新型层状WS₂由1T' WS₂单层构建而成并被合成出来。基于每个晶胞中的层数和从属晶体学系统，其相被定义为2M。在2M WS₂中观察到本征超导性，其转变温度T为8.8 K，这在未经过任何微调过程的TMDs中是最高的。此外，通过舒布尼科夫-德哈斯振荡和第一性原理计算发现，2M WS₂的电子结构具有很强的各向异性。另外，通过第一性原理计算预测，具有由拓扑不变量Z₂保护的单个狄拉克锥的拓扑表面态存在。这些发现表明，新型2M WS₂可能是一种来自VIB族过渡金属二硫属化物的有趣的拓扑超导候选物。
