Charge Sensing of Fractional Quantum Hall States in Monolayer Graphene: Part II

The fractional quantum Hall effect is an exotic, highly entangled state arising from the interplay of topology and correlations. This intriguing incompressible state hosts exotic excitations with fractional charge and unconventional exchange statistics that can only exist in two dimensions. In the second talk of this series, I will show how we employ a novel charge sensing method to study fractional quantum Hall states in monolayer graphene (C. L. Chiu et al. [1]). This technique, based on scanning tunneling microscopy, allows us to probe the chemical potential locally with a high spatial resolution. In particular, we focus on the response of chemical potential to local potentials from naturally occurring substrate defects. In the future, this method can be used to detect individual charging events of fractional quasiparticles at the impurities, visualizing the charge distribution in real space and allowing for the extraction of the particle’s angular momentum and the total trapped charge.

[1] Cheng-Li Chiu et al., High spatial resolution charge sensing of quantum Hall states. Preprint at https://doi.org/10.48550/arXiv.2410.10961 (2024).