Electronic Compressibility of Magic-Angle Graphene Superlattices

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We report the first electronic compressibility measurements of magic-angle twisted bilayer graphene.

• The evolution of the compressibility with carrier density offers insights into the interaction-driven ground state that have not been accessible in prior transport and tunneling studies.
• From capacitance measurements, we determine chemical potential as a function of carrier density and find the widths of the energy gaps at fractional filling of the moir\'{e} lattice.
• In the electron-doped regime, we observe unexpectedly large gaps at quarter- and half-filling and strong electron-hole asymmetry.