Rotatable heterostructures with bilayer graphene and hexagonal boron nitride

Since the discovery of graphene, the development of van der Waals heterostructures has offered an unprecedented research playground for a wide range of remarkable breakthroughs in nanoscience. More recently, the study of how the twist angle between two layers can change the properties of the assembled materials has been a major point of interest, especially since the discovery of superconductivity in twisted bilayer graphene in 2018. This work focuses on the case of an heterostructure in which hexagonal boron nitride (hBN) that is stacked and twisted on bilayer graphene (BLG), in a rotatable configuration. The aim is to investigate different phenomena arising at low angle, and on the other hand the angle dependence of electrical, optical, and frictional properties of the heterostructure. In this master thesis, the fabrication of a device allowing to study the twist angle effect in the hBN/BLG interface experimentally is presented, as well as the frictional, electrical and Raman measurements that were conducted on it. Friction measurements on hBN/BLG yielded results with clear differences from the monolayer graphene/hBN case, and some hints for peculiar stable configurations at low twist angle. These observations forecast potential exciting findings in low angle states of the BLG/hBN superstructure that need to be confirmed, thus paving the way to further experimental and/or simulation studies.