Direct visualization of electrostatic gating on the band structure of two-dimensional materials via Angled Resolved Photo Emission Spectroscopy (ARPES)

The ability to manipulate the band structure of two-dimensional (2D) materials via electrostatic gating is crucial for the realization of technological applications and study of fundamental physics with these materials. ARPES is the standard experimental technique for band structure visualization, however, to this date, the direct visualization of electrostatic gating on the band structure of 2D materials is lacking. Several obstacles have precluded the incorporation of electrostatic gating with ARPES measurements such as sample size, surface uniformity, and a working gate electrode. To address these obstacles, we performed ARPES experiments with submicron spatial resolution on a heterostructure of bilayer graphene (BLG) and hexagonal boron nitride (hBN) that is back gated with an underlying graphite flake. We found that such a device geometry enabled direct visualization of the BLG bands in conjunction with their shift via electrostatic gating. We will discuss the latest experimental progress towards the direct visualization of electrostatic gate modulation of BLG bands.