On the mechanism of high-temperature superconductivity in hydrogen sulfide at 200GPa: Transition into superconducting anti-adiabatic state in coupling to H-vibrations

It has been shown that the adiabatic electronic structure of the superconducting phase of sulfur hydride at 200GPa is unstable toward the vibration motion of H-atoms. A theoretical study indicates that in coupling to H-vibrations, the system undergoes a transition from adiabatic into a stabilized anti-adiabatic multi-gap superconducting state at a temperature that can reach 203K.