Superconductivity determined by the S-H framework in CH4-inserted S-H framework hydrides under high pressures

Shunwei Yao; Wenjing Hu; Ben Wang; Lin Peng; Tingting Shi; Xiaolin Liu; Jing Chen; Jia Lin; Dao-Xin Yao; Xianfeng Chen

doi:10.1063/5.0158303

Superconductivity determined by the S-H framework in CH4-inserted S-H framework hydrides under high pressures

J Chem Phys. 2023 Jul 28;159(4):044714. doi: 10.1063/5.0158303.

Authors

Shunwei Yao¹, Wenjing Hu¹, Ben Wang¹, Lin Peng¹, Tingting Shi², Xiaolin Liu¹, Jing Chen¹, Jia Lin¹, Dao-Xin Yao³, Xianfeng Chen^{4

5}

Affiliations

¹ Department of Physics, Shanghai University of Electric Power, Shanghai 200090, China.
² Department of Physics, Jinan University, Guangzhou 510632, China.
³ State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
⁴ State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
⁵ Collaborative Innovation Center of Light Manipulation and Applications, Shandong Normal University, Jinan 250358, China.

PMID: 37522408
DOI: 10.1063/5.0158303

Abstract

Recently, a debate is raising the concern of possible carbonaceous sulfur hydrides with room-temperature superconductivity around 270 GPa. In order to systematically investigate the structural information and relevant natures of C-S-H superconductors, we performed an extremely extensive structure search and first-principles calculations under high pressures. As a result, the metastable stoichiometries of CSH7, C2SH14, CS2H10, and CS2H11 were unveiled under high pressure, which can be viewed as CH4 units inserted into the S-H framework. Given the super-high superconductivity of Im3̄m-SH3, we performed electron-phonon coupling calculations of these compounds,the metastable of R3m-CSH7, Cm-CSH7, Cm-CS2H10, P3m1-CS2H10, Cm-CS2H11, and Fmm2-CS2H11 are predicted to become good phonon-mediated superconductors that could reach Tc of 130, 120, 72, 74, 92, and 70 K at 270 GPa, respectively. Furthermore, we identified that high Tc is associated with the large contribution of the S-H framework to the electron density of states near the Fermi level. Our results highlight the importance of the S-H framework in superconductivity and verify that the suppression of density of states of these carbonaceous sulfur hydrides by CH4 units results in Tc lower than that of Im3̄m-SH3, which could act as a useful guidance in the design and optimization of high-Tc superconductors in these and related systems.