Absence of conventional room-temperature superconductivity at high pressure in carbon-doped <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi mathvariant="normal">H</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mi mathvariant="normal">S</mml:mi></mml:mrow></mml:math>
Tianchun Wang, Motoaki Hirayama, Takuya Nomoto, Takashi Koretsune, Ryotaro Arita, José A. Flores‐Livas
Abstract
In this paper, we show that the same theoretical tools that successfully explain other hydride systems under pressure seem to be at odds with the recently claimed conventional room-temperature superconductivity of carbonaceous sulfur hydride. We support our conclusions with (i) the absence of a dominant low-enthalpy stoichiometry and crystal structure in the ternary phase diagram. (ii) Only the thermodynamics of C-doping phases appears to be marginally competing in enthalpy against ${\mathrm{H}}_{3}\mathrm{S}$. (iii) Accurate results of the transition temperature given by ab initio Migdal-Eliashberg calculations differ by more than 110 K from recent theoretical claims explaining the high-temperature superconductivity in carbonaceous hydrogen sulfide. An unconventional mechanism of superconductivity or a breakdown of current theories in this system is possibly behind the disagreement.