The strain effect on superconductivity in phosphorene: a first-principles prediction

Abstract

The effects of biaxial and uniaxial strains on electron–phonon coupling and superconductivity in monolayer phosphorene are systematically investigated by first-principles calculations. It is found that the electron–phonon coupling primarily comes from the low frequency optical phonon modes around ${\rm B}_{3g}^{1}$ , and the biaxial strain gives rise to more a obvious increase in density of states around the Fermi level and phonon softening in the low frequency regime compared to the other two types of uniaxial strain. Therefore, the electron–phonon coupling is more significantly enhanced by the biaxial strain than the uniaxial strains and the superconducting transition temperature T _c increases sharply from 3 K to 16 K at the typical doping concentration n _2D = 3.0 × 10 ^14 cm ^−2 when the biaxial strain reaches 4.0%.