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arXiv · 1912.01860

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

Stiven Forti·Stefan Link·Alexander Stöhr·Yuran Niu·Alexei A. Zakharov·Camilla Coletti·Ulrich Starke
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Abstract

The synthesis of transition metals in a two-dimensional (2D) fashion 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 (ML) 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 novel class of van der Waals heterostructure. The 2D-Au bands, exhibit a 225 meV spin-orbit splitting along the {\Gamma 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 was never observed before and hosts great interest for fundamental physics.

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Stiven Forti, Stefan Link, Alexander Stöhr, Yuran Niu, Alexei A. Zakharov, Camilla Coletti, Ulrich Starke. 2019-12-04. Semiconductor to metal transition in two-dimensional gold and its van der Waals heterostack with graphene. https://doi.org/10.1038/s41467-020-15683-1

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