Comparison of pressurized sulfur hydride with conventional superconductors

Abstract

A recent report that sulfur hydride under pressure is an electron-phonon superconductor with a Tc of 190 K has been met with much excitement although it is yet to be confirmed. Based on several electron-phonon spectral density functions already available from density functional theory, we find that the electron-phonon spectrum is near optimum for Tc with a particularly large value of its characteristic phonon energy omega_ln which is due to the small hydrogen mass. We find that the thermodynamic universal BCS ratios are near those for Pb and Nb3Sn. We suggest that optical measurements could be a useful tool to establish the existence and nature of the superconductivity in this system. Conventional superconductors are in the impurity-dominated dirty limit. By contrast sulfur hydride will be in the clean limit because of its large energy gap scale. The AC optical conductivity will display distinct and separate signatures of the superconducting gap in the low-energy impurity-dominated range of the optical spectrum and additional phonon structures at higher energies where the clean limit applies.

5 pages with 3 figures, 2 pages of supplementary material with 3 figures

References in corpus (5)

• Hydrogen sulphide at high pressure: a strongly-anharmonic phonon-mediated superconductor
• What superconducts in sulfur hydrides under pressure, and why
• Cubic H${}_3$S around 200 GPa: an atomic hydrogen superconductor stabilized by sulfur
• Hole superconductivity in $H_{2}S$ and other sulfides under high pressure
• Optical self-energy of superconducting Pb in the THz region

Cited by in corpus (19)

• Nonstandard superconductivity or no superconductivity in hydrides under high pressure
• Electron-phonon coupling mechanisms for hydrogen-rich metals at high pressure
• Quantitative analysis of nonadiabatic effects in dense H${}_3$S and PH${}_3$ superconductors
• Hole-Doped Room-Temperature Superconductivity in H${}_3$S${}_{1-x}$Z${}_x$ (Z=C, Si)
• London penetration depth and thermal fluctuations in the sulphur hydride 203 K superconductor
• Classifying superconductivity in compressed H3S
• Meissner effect in nonstandard superconductors
• Future Study of Dense Superconducting Hydrides at High Pressure
• Classifying superconductivity in ThH-ThD superhydrides/superdeuterides
• The electron-phonon coupling constant, the Fermi temperature and unconventional superconductivity in the carbonaceous sulfur hydride 190 K superconductor
• Absence of evidence of superconductivity in sulfur hydride in optical reflectance experiments
• Comparison of highly-compressed C2/m-SnH12 superhydride with conventional superconductors
• Hydrogen in superconductors
• Optical properties of superconducting pressurized LaH${}_{10}$
• Spectroscopic signatures of phonons in high pressure superconducting hydrides
• The higher superconducting transition temperature T${}_c$ and the functional derivative of T${}_c$ with ${\alpha }^{2}F(\omega )$ for electron-phonon superconductors
• Massive electrons and unconventional room-temperature superconductivity in superhydrides
• Effect of van Hove singularity on the isotope effect and critical temperature of H${}_3$S hydride superconductor as a function of pressure
• The Isotope Effect and Critical Magnetic Fields of Superconducting YH${}_6$: A Migdal-Eliashberg Theory Approach