  Integrating the carrier tunability of a functional two-dimensional material
electronic device with a direct probe of energy- and momentum-resolved
electronic excitations is essential to gain insights on how many-body
interactions are influenced during device operation. Here, we use micro-focused
angle-resolved photoemission in order to analyze many-body interactions in
back-gated graphene supported on hexagonal boron nitride. By extracting the
doping-dependent quasiparticle dispersion and self-energy, we observe how these
interactions renormalize the Dirac cone and impact the electron mobility of our
device. Our results are not only limited to a finite energy range around the
Fermi level, as in electron transport measurements, but describe interactions
on a much wider energy scale, extending beyond the regime of hot carrier
excitations.
