Modified Dirac fermions in the crystalline xenon and graphene Moir\'{e} heterostructure

TL;DR

This study demonstrates how a Moire superstructure forms between graphene and xenon, a noble gas, altering the electronic properties of graphene through enhanced dielectric screening, with implications for 2D material engineering.

Contribution

It introduces a novel method to create Moire superstructures using noble gas adsorption on 2D materials, and shows how this affects Dirac fermion velocities.

Findings

Formation of a Moire superstructure between graphene and xenon.

Increased Dirac fermion velocity due to xenon layer.

Enhanced dielectric screening from xenon layer.

Abstract

The interface between two-dimensional (2D) crystals often forms a Moire superstructure that imposes a new periodicity, which is a key element in realizing complex electronic phases as evidenced in twisted bilayer graphene. A combined angle resolved photoemission spectroscopy measurements and first-principles calculations reveal the formation of a Moire superstructure between a 2D Dirac semi-metallic crystal, graphene, and a 2D insulating crystal of noble gas, xenon. Incommensurate diffraction pattern and folded Dirac cones around the Brillouin zone center imply the formation of hexagonal crystalline array of xenon atoms. The velocity of Dirac fermions increases upon the formation of the 2D xenon crystal on top of graphene due to the enhanced dielectric screening by the xenon over-layer. These findings not only provide a novel method to produce a Moire superstructure from the adsorption of noble gas on 2D materials, but also to control the physical properties of graphene by the formation of a graphene-noble gas interface.