Emergent topological superconductivity in Bi-intercalated van der Waals layered SiTe2

Abstract

Van der Waals (vdW) layered materials have attracted extensive attention and become a platform for investigating various exotic physical properties of interest. Considering experimentally synthesized vdW layered ${\mathrm{SiTe}}_{2}$ and monolayer Bi, here we propose a feasible way to obtain topological superconductivity by intercalating monolayer Bi into the bulk ${\mathrm{SiTe}}_{2}$. Using Allen-Dynes-modified McMillan equation based on the first principles calculations, we predict the bulk ${\mathrm{SiTe}}_{2}$ to be a superconductor with superconducting transition temperature ${\mathrm{T}}_{C}$ of about 2.9 K, which could be effectively modulated by hydrostatic and uniaxial pressures. Intercalating a two-dimensional topological insulator Bi into the bulk ${\mathrm{SiTe}}_{2}$, we find that the system exhibits both superconductivity with ${\mathrm{T}}_{C}$ of about 1.7 K and topological surface states near the Fermi energy. In addition, the ${\mathrm{T}}_{C}$ of ${\mathrm{SiTe}}_{2}$ monolayer remains almost intact when exfoliated from its bulk. Our work paves a new way to realize topological superconductivity by intercalating topological matter into vdW layered materials.