Hole-Doped Room-Temperature Superconductivity in H$_{3}$S$_{1-x}$Z$_x$ (Z=C, Si)

TL;DR

This study demonstrates that hole doping in H₃S by substituting S with C or Si can significantly increase the superconducting critical temperature to near room temperature, offering new pathways for high-temperature superconductivity in hydrogen-rich materials.

Contribution

It introduces a method of hole doping via atomic substitution to enhance Tc in H₃S, achieving record-high superconducting temperatures at high pressures.

Findings

Critical temperature increased to 289 K with C doping.

Critical temperature increased to 283 K with Si doping.

Hole doping aligns the Fermi level with the density-of-states peak.

Abstract

We examine the effects of the low-level substitution of S atoms by C and Si atoms on the superconductivity of H$_3$S with the $Im\bar{3}m$ structure at megabar pressure. The hole doping can fine-tune the Fermi energy to reach the electronic density-of-states peak maximizing the electron-phonon coupling. This can boost the critical temperature from the original 203 K to 289 K and 283 K, respectively, for H$_3$S$_{0.962}$C$_{0.038}$ at 260 GPa and H$_3$S$_{0.960}$Si$_{0.040}$ at 230 GPa. The former may provide an explanation for the recent experimental observation of room-temperature superconductivity in a highly compressed C-S-H system [Nature 586, 373-377 (2020)]. Our work opens a new avenue for substantially raising the critical temperatures of hydrogen-rich materials.