Strain-induced modulations of electronic structure and electron-phonon coupling in dense H3S.

A ∼200 K superconducting phase in dense hydrogen sulfide is an important milestone for the development of novel superconductors with high critical temperature. Here, we systematically studied the effect of uniaxial strain on the electronic and superconducting properties in dense H3S using density functional calculations. Our theoretical results show that inducing strain is an effective tool to control the electronic Fermi surface topology, logarithmic average frequency, and electron-phonon coupling parameter of dense H3S. Thus, uniaxial strain induces sensitive and considerable changes in superconducting critical temperature, which stem from the energy-level shifts and softening lattice vibrations.