Semiconductor to metal transition in two-dimensional gold and its van der Waals heterostack with graphene

Research output: Contribution to journalArticle

Abstract

The synthesis of two-dimensional (2D) transition metals has attracted growing attention for both fundamental and application-oriented investigations, such as 2D magnetism, nanoplasmonics and non-linear optics. However, the large-area synthesis of this class of materials in a single-layer form poses non-trivial difficulties. Here we present the synthesis of a large-area 2D gold layer, stabilized in between silicon carbide and monolayer graphene. We show that the 2D-Au ML is a semiconductor with the valence band maximum 50 meV below the Fermi level. The graphene and gold layers are largely non-interacting, thereby defining a class of van der Waals heterostructure. The 2D-Au bands, exhibit a 225 meV spin-orbit splitting along the Γ K ¯ direction, making it appealing for spin-related applications. By tuning the amount of gold at the SiC/graphene interface, we induce a semiconductor to metal transition in the 2D-Au, which has not yet been observed and hosts great interest for fundamental physics.

Details

Authors
  • Stiven Forti
  • Stefan Link
  • Alexander Stöhr
  • Yuran Niu
  • Alexei A. Zakharov
  • Camilla Coletti
  • Ulrich Starke
Organisations
External organisations
  • Max Planck Institute for Solid State Research
  • Italian Institute of Technology
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Condensed Matter Physics
Original languageEnglish
Article number2236
JournalNature Communications
Volume11
Issue number1
Publication statusPublished - 2020 May 6
Publication categoryResearch
Peer-reviewedYes