Abstract
Recently, the discovery of room-temperature superconductivity (SC) was experimentally realized in the fcc phase of under megabar pressure. Specifically, the isotope effect of was measured by the replacement of hydrogen (H) with deuterium (D), demonstrating a driving role of phonons in the observed room-temperature SC. Herein, based on the first-principles calculations within the harmonic approximation, we reveal that (i) the identical electron-phonon coupling constants of fcc and decrease monotonously with increasing pressure and (ii) the isotope effect of is nearly proportional to (: ionic mass) with 0.465, irrespective of pressure. The predicted value of agrees well with the experimental one () measured at around 150 GPa. Thus, our findings provide a theoretical confirmation of the conventional electron-phonon coupling mechanism in a recently discovered room-temperature superconductor of compressed .
- Received 10 December 2019
- Revised 12 May 2020
- Accepted 14 May 2020
DOI:https://doi.org/10.1103/PhysRevB.101.214501
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