Martin, JensFeldman, Benjamin EzekielWeitz, R.Allen, MonicaYacoby, Amir2012-01-242010Martin, Jens, Benjamin Feldman, R. Weitz, Monica Allen, and Amir Yacoby. 2010. Local compressibility measurements of correlated states in suspended bilayer graphene. Physical Review Letters 105(25): 256806.1079-7114http://nrs.harvard.edu/urn-3:HUL.InstRepos:8013321Bilayer graphene has attracted considerable interest due to the important role played by many-body effects, particularly at low energies. Here we report local compressibility measurements of a suspended graphene bilayer. We find that the energy gaps at filling factors v = 4 do not vanish at low fields, but instead merge into an incompressible region near the charge neutrality point at zero electric and magnetic field. These results indicate the existence of a zero-field ordered state and are consistent with the formation of either an anomalous quantum Hall state or a nematic phase with broken rotational symmetry. At higher fields, we measure the intrinsic energy gaps of broken-symmetry states at v = 0, +/-1 and +/-2, and find that they scale linearly with magnetic field, yet another manifestation of the strong Coulomb interactions in bilayer graphene.en-USmesoscale and nanoscale physicsJournal Article2012-01-2410.1103/PhysRevLett.105.256806