Semiconductor, topological semimetal, indirect semimetal, and topological Dirac semimetal phases of Ge1-xSnx alloys
Journal
Physical Review B
Journal Volume
95
Journal Issue
20
Date Issued
2017
Author(s)
Abstract
Electronic structures of Ge1-xSnx alloys (0?x?1) are theoretically studied by the nonlocal empirical pseudopotential method. For relaxed Ge1-xSnx, a topological semimetal is found for x>41% with gapless and band inversion at the Γ point, while there is an indirect-direct band-gap transition at x=8.5%. For strained Ge1-xSnx on a Ge substrate, semimetals with a negative indirect band gap appear for x>43%, and the strained Ge1-xSnx on Ge is always an indirect band-gap semiconductor for x<43%. With appropriate biaxial compressive strains, a topological Dirac semimetal is found with band inversion at Γ and one pair of Dirac cones along the [001] direction. ? 2017 American Physical Society.
Type
journal article