Plasmons in nanostructured and corrugated 2D materials

B. Majérus1, P. Vancsó2, G. Dobrik2, P. Nemes-Incze2, P. Süle2, G. Piszter2, M. Menyhárd2, B. Kalas2, P. Petrik2, L. Tapasztó2, L. Henrard1

1 Namur Institute of Structured Matter (NISM), University of Namur (UNamur), Belgium
Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest, Hungary

Graphene has been focusing attention as a support for plasmon for over a decade. In order to obtain plasmon resonance in the visible range, graphene nanoparticles or nanoribbon have been largely investigated. However, the intervalley scattering due to the edges is a critical source of damping of plasmon resonances in nanostructured graphene. In edge-free highly corrugated graphene, nanoscale confinement of charge carriers without intervalley scattering is possible. We theoretically evidence the appearance of plasmon excitations in the IR/Visible related to such corrugation (figure 1). These results are supported by SERS measurements on corrugated graphene suggesting the existence of plasmon in corrugated graphene1.

We also investigate 1D plasmon in other 2D materials. Due to the reduced dimensionality of such plasmons, one can expect even larger confinements of light. Some 1D plasmons are associated to atomic reconstructions at the edge of nanoribbon or at grain boundaries that can be at the origin of a 1D metallic channel in 2D materials. In this work, we theoretically examine the metallic behavior of experimentally observed mirror twin boundaries in transition metal dichalcogenide (TMDs) and show that 1D plasmon can be sustained in such nanostructures.

The plasmonic excitations are analyzed using an eigenmode decomposition of the microscopic dielectric function obtained by DFT simulations available in the GPAW code.

Figure 1: Charge distributions of optical excitations corresponding to loss peak near 1.9 eV and 2.9 eV
from our calculated EELS spectrum of a model graphene nanocorrugation.


1. G. Dobrik, P. Nemes-Incze, B. Majérus, P. Süle, P. Vancsó, G. Piszter, M. Menyhárd, B. Kalas, P. Petrik, L. Henrard and L. Tapasztó. Large-area nanoengineering of graphene corrugations for visible-frequency graphene plasmons. Nat. Nano. In press.