# Dirac Cone Pairs in Silicene Induced by Interface Si-Ag Hybridization: A First Principles Effective Band Study

## TL;DR

This study uses first-principles calculations to reveal that interface hybridization in silicene/Ag structures induces Dirac cone pairs, differing from freestanding silicene, aligning with recent ARPES experimental data.

## Contribution

It demonstrates that interfacial Si-Ag hybridization creates Dirac cones in silicene on Ag(111), a novel mechanism distinct from intrinsic silicene properties.

## Key findings

- Six pairs of Dirac cones near the BZ boundary of Ag(1x1)
- Dirac cones are induced by Si-Ag hybridization
- No Dirac cones observed inside the BZ

## Abstract

Using density functional theory combined with orbital-selective band unfolding techniques, we study the effective band structure of silicene($3\times3$)/Ag(111)($4\times4$) structure. Consistent with the ARPES spectra recently obtained by Feng et al. [Proc. Natl. Acad. Sci. 113, 14656 (2016)], we observe six pairs of Dirac cones near the boundary of the Brillouin zone (BZ) of Ag($1\times1$), while no Dirac cone is observed inside the BZ. Furthermore, we find that these Dirac cones are induced by the interfacial Si-Ag hybridization, mainly composed of Si p$_z$ orbitals and Ag sp bands, which is intrinsically different from the Dirac cones in freestanding silicene.