Abstract
Based on first-principles density functional calculations, we report the existence of both nontrivial band topology and superconductivity in three metallic Si allotropes, termed , , and . and are predicted in this study, whereas was proposed in previous theoretical calculations. These metastable allotropes retain their crystalline structure at ambient pressure and exhibit superconductivity at the critical temperatures of 1.2–11.4 K. We investigate the topological characteristics of the electronic states and find the weak topological nature for all three allotropes. For , in particular, the formation of the surface Dirac point is clearly identified. Our result provides a promising platform for realizing a topological superconducting state in all-Si systems at ambient pressure.
1 More- Received 22 July 2021
- Accepted 4 October 2021
DOI:https://doi.org/10.1103/PhysRevMaterials.5.104802
©2021 American Physical Society