Dirac Signature in Germanene on Semiconducting Substrate.

ABSTRACT: 2D Dirac materials supported by nonmetallic substrates are of particular interest due to their significance for the realization of the quantum spin Hall effect and their application in field-effect transistors. Here, monolayer germanene is successfully fabricated on semiconducting germanium film with the support of a Ag(111) substrate. Its linear-like energy-momentum dispersion and large Fermi velocity are derived from the pronounced quasiparticle interference patterns in a ?3 × ?3 superstructure. In addition to Dirac fermion characteristics, the theoretical simulations reveal that the energy gap opens at the Brillouin zone center of the ?3 × ?3 restructured germanene, which is evoked by the symmetry-breaking perturbation potential. These results demonstrate that the germanium nanosheets with ?3 × ?3 germanene can be an ideal platform for fundamental research and for the realization of high-speed and low-energy-consumption field-effect transistors.

SUBMITTER: Zhuang J 

PROVIDER: S-EPMC6051399 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature