Superconductivity in high-pressure SiH ₄

Abstract

A combination of static and dynamical first-principles electronic calculations of silane, SiH4, at high pressure has revealed a novel monoclinic structure with C2/c symmetry. This high-pressure phase is metallic and composed of layers of SiH4 bridged by H bonds. Perturbative linear response calculations at 90 and 125 GPa predict large electron-phonon couplings yielding an electron-phonon coupling parameter λ close to 0.9. The application of McMillan equation gives a superconducting critical temperature (Tc) between 45 and 55 K.