Structural and Electronic Properties of Twisted Bilayer Graphene/h-BN Systems | Ying Wang (University of Groningen)

Twisted bilayer graphene (TBG) has garnered significant attention in condensed matter physics due to its potential to exhibit superconductivity and other correlated electronic states, particularly at the so-called "magic angle". However, the properties of TBG are strongly influenced not only by the twist angle between graphene layers but also by factors such as strain-induced moiré uniformity and substrate effects. In this talk, we present a comprehensive study that combines conductive atomic force microscopy (c-AFM) with low-temperature electronic transport measurements to investigate the moiré lattice structures and electronic properties of twisted bilayer graphene.

Our findings reveal that the flat electronic bands near the first magic angle are crucial in the emergence of correlated insulating states and orbital magnetism, driven by strong electron-electron interactions. Additionally, we explore the interlayer coupling and the behavior of degeneracy-broken quantum Hall states by manipulating specific alignment conditions in TBG/h-BN systems with larger twist angles. These results deepen our understanding of the intricate relationship between moiré lattice structures and electronic properties in TBG, and they open new avenues for the development of quantum materials and their applications in the emerging field of twistronics.