  Magic-angle twisted bilayer graphene (MA-tBLG) has appeared as a tunable
testing ground to investigate the conspiracy of electronic interactions, band
structure, and lattice degrees of freedom to yield exotic quantum many-body
ground states in a two-dimensional Dirac material framework. While the impact
of external parameters such as doping or magnetic field can be conveniently
modified and analyzed, the all-surface nature of the quasi-2D electron gas
combined with its intricate internal properties pose a challenging task to
characterize the quintessential nature of the different insulating and
superconducting states found in experiments. We analyze the interplay of
internal screening and dielectric environment on the intrinsic electronic
interaction profile of MA-tBLG. We find that interlayer coupling generically
enhances the internal screening. The influence of the dielectric environment on
the effective interaction strength depends decisively on the electronic state
of MA-tBLG. Thus, we propose the experimental tailoring of the dielectric
environment, e.g. by varying the capping layer composition and thickness, as a
promising pursuit to provide further evidence for resolving the hidden nature
of the quantum many-body states in MA-tBLG.

Strongly Correlated Electrons;Mesoscale and Nanoscale Physics;Superconductivity