Superconducting two-dimensional penta materials

Abstract

Successful experimental synthesis and theoretical prediction of two-dimensional (2D) penta materials with various properties have enriched the family of 2D materials. In this work, based on first-principles calculations, we systematically study the electronic structures, phonon dispersions, and electron-phonon coupling (EPC) of four metallic penta materials ‘XY2’ (NC2, PC2, BN2, and BP2). Three of them display weak phonon-mediated superconductivity with different low superconducting transition temperatures (Tc). The highest Tc among them is 12 K for BP2. Through applying biaxial tensile strain, the λ and Tc of PC2 (BN2) can be enhanced up to 1.64 (2.68) and 49.77 (52.29) K, respectively. By solving the anisotropic Eliashberg equations, single-gap superconducting nature is predicted for PC2 and BN2. The high sensitive of superconductivity in these systems clearly demonstrate that they are potential candidates for applications in using as superconducting nanodevices. Our work will stimulate further searching of high-Tc superconductivity in low-dimensional materials.