Enhanced superconductivity in C-S-H compounds at high pressure

Recently, the superconducting transition temperature ${T}_{c}=287\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ has been experimentally obtained in a material composed of carbon, sulfur, and hydrogen under high pressure 267 GPa. The structure is currently unknown, where carbon sulfur were added at molar ratio $1:1$. Here, fixing $\text{C}:\text{S}=1:1$, we studied several possible C-S-H structures, found stable ${\mathrm{C}}_{2}{\mathrm{S}}_{2}{\mathrm{H}}_{4}$ using first-principles calculations. shows an insulator-to-metal ground state 64 GPa, its ${T}_{c}$ can reach 16.5 K 300 In addition, another ${\mathrm{C}}_{2}{\mathrm{S}}_{3}{\mathrm{H}}_{4}$, whose 47.4 calculations show that S atom ${\mathrm{C}}_{2}{\mathrm{S}}_{3}{\mathrm{H}}_{4}$ breaks part C-H bonds ${\mathrm{C}}_{2}{\mathrm{S}}_{2}{\mathrm{H}}_{4}$, makes vibration H occur lower frequency, thus enhances electron-phonon coupling ${T}_{c}$. Our results suggest $\text{C}:\text{S}$ than $1:1$ systems may be favorable to enhance This useful figure out with room-temperature recent experiment.