  We employ dual-gated 30{\deg}-twisted bilayer graphene to demonstrate
simultaneous ultra-high mobility and conductivity (up to 40 mS at room
temperature), unattainable in a single-layer of graphene. We find quantitative
agreement with a simple phenomenology of parallel conduction between two
pristine graphene sheets, with a gate-controlled carrier distribution. Based on
the parallel transport mechanism, we then introduce a method for in situ
measurements of the chemical potential of the two layers. This twist-enabled
approach, neither requiring a dielectric spacer, nor separate contacting, has
the potential to greatly simplify the measurement of thermodynamic quantities
in graphene-based systems of high current interest.
