The characterization of high-pressure superconducting state in Si2H6 compound: the strong-coupling description

TL;DR

This study investigates the high-pressure superconducting state of Si2H6 at 275 GPa using Eliashberg formalism, revealing extremely high critical temperatures, strong-coupling effects, and large electron effective masses.

Contribution

It provides a detailed strong-coupling analysis of Si2H6's superconductivity under high pressure, extending understanding beyond BCS predictions.

Findings

Critical temperature up to 173.36 K at μ* = 0.1

Energy gap ratio exceeds BCS value, indicating strong coupling

Electron effective mass reaches 2.397 times the band mass

Abstract

The thermodynamic parameters of the superconducting state, that induces in ${\rm Si_{2}H_{6}}$ under the pressure at 275 GPa, have been calculated. In the framework of the Eliashberg formalism, it has been shown that the critical temperature can attain extremely high values: $T_{C}(\mu^{\star})\in<173.36, 99.99>$ K, where the Coulomb pseudopotential $(\mu^{\star})$ belongs to the range from 0.1 to 0.3. The ratio of the energy gap to the critical temperature ($R_{\Delta}$) significantly exceeds the value predicted by the BCS theory: $R_{\Delta}(\mu^{\star})\in<4.40, 4.04>$. Additionally, it has been stated that in the whole range of the superconducting state's existence, the electron effective mass ($m^{\star}_{e}$) is large; $[m^{\star}_{e}]^{\rm max}_{T=T_{C}}=2.397m_{e}$, where the symbol $m_{e}$ denotes the electron band mass.