Phonon-mediated superconductivity in orthorhombic XS(X=Nb,Ta or W)  

作　　者：Guo-Hua Liu Kai-Yue Jiang Yi Wan Shu-Xiang Qiao Jin-Han Tan Na Jiao Ping Zhang Hong-Yan Lu 刘国华;江恺悦;万一;乔树祥;谭锦函;焦娜;张平;路洪艳

机构地区：[1]School of Physics and Physical Engineering,Qufu Normal University,Qufu 273165,China [2]Institute of Applied Physics and Computational Mathematics,Beijing 100088,China

出　　处：《Chinese Physics B》2025年第2期419-423,共5页中国物理B(英文版)

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.12074213 and 11574108);the Major Basic Program of Natural Science Foundation of Shandong Province(Grant No.ZR2021ZD01);the Natural Science Foundation of Shandong Province(Grant No.ZR2023MA082);the Project of Introduction and Cultivation for Young Innovative Talentsin Colleges and Universities of Shandong Province。

摘　　要：The unique three-dimensional orthorhombic NbS(o-NbS)compound synthesized in 1969 has recently been experimentally confirmed to be a superconductor[Phys.Rev.B 108174517(2023)].However,there is currently no theoretical research on its superconducting mechanism.In this work,we investigate the superconducting properties of o-Nb S from first-principles calculations.Based on the Eliashberg equation,it is found that the superconductivity mainly originates from the coupling between the electrons of Nb-4d orbitals and the vibrations of Nb atoms in the low-frequency region and those of S atoms in the high-frequency region.A superconducting transition temperature(T_c)of 10.7 K is obtained,which is close to the experimental value and higher than most transition metal chalcogenides(TMCs).The calculated thermodynamic properties in the superconducting state,such as specific heat,energy gap,isotope coefficient,etc.,also indicate that o-NbS is a conventional phonon-mediated superconductor.These results are consistent with recent experimental reports and provide a good understanding of the superconducting mechanism of o-Nb S.Furthermore,the TMCs of o-TaS and o-WS are also investigated;these belong to the same and neighboring groups of Nb,and we find that o-TaS and o-WS are also phonon-mediated superconductors with T_c of 8.9 K and 7.2 K,respectively.

关 键 词：first-principles calculations phonon-mediated superconductivity orthorhombic transition metal chalcogenides 

分 类 号：O62[理学—有机化学]