Probing the structure and composition of van der Waals heterostructures using the nonlocality of Dirac plasmons in the terahertz regime. (30th October 2020)

• Record Type: Journal Article
• Authors: Lavor, I R; Cavalcante, L S R; Chaves, Andrey; Peeters, F M; Van Duppen, B
• Is Part Of: 2D materials. Volume 8:Number 1(2021)
• Publication Date: 2020-10-30
• Subjects: graphene -- dirac plasmons -- transition metal dichalcogenide -- van der waals heterostructures -- phonons -- plasmon-phonon hybridization; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/abbecc
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: Dirac plasmons in graphene are very sensitive to the dielectric properties of the environment. We show that this can be used to probe the structure and composition of van der Waals heterostructures (vdWh) put underneath a single graphene layer. In order to do so, we assess vdWh composed of hexagonal boron nitride and different types of transition metal dichalcogenides (TMDs). By performing realistic simulations that account for the contribution of each layer of the vdWh separately and including the importance of the substrate phonons, we show that one can achieve single-layer resolution by investigating the nonlocal nature of the Dirac plasmon-polaritons. The composition of the vdWh stack can be inferred from the plasmon-phonon coupling once it is composed by more than two TMD layers. Furthermore, we show that the bulk character of TMD stacks for plasmonic screening properties in the terahertz regime is reached only beyond 100 layers.