The investigation of the hydride superconductor's parabolic-like critical temperature under high pressure

Abstract

Under the weak coupling, we investigate the critical temperatures under pressure of H3S, LaH10, CaH6, and Tl2Ba2CaCu2O8+{\delta} superconductors. The superconducting mechanism takes into account the electron-phonon interaction as well as the Coulomb interaction. Under high pressure, the critical temperature equation is calculated as a function of the fractional volume of the unit cell, and the Birch-Murnaghan equation of state is used to determine the relationship between fraction volume and pressure. Using this equation, we can analyze the parabolic-like relationship between the critical temperature and pressure of a superconductor. The parabolic behavior of these superconductors' critical temperature versus pressure can fit well. The maximal critical temperature of Tl2Ba2CaCu2O8+{\delta}, H3S, LaH10, and CaH6 superconductors are predicted to be 112 K at 7 GPa, 197 K at 140 GPa, 252 K at 143 GPa, and 207 K at 174 GPa, respectively.