Transport spectroscopy in bilayer graphene using double layer heterostructures

Abstract

We provide a comprehensive study of the chemical potential of bilayer graphene in a wide range of carrier density, at zero and high magnetic (B)-fields, and at different transverse electric (E)-fields, using high quality double bilayer graphene heterostructures. Using a direct thermodynamic transport spectroscopic technique, we probe the chemical potential as a function of carrier density in six samples. The data clearly reveal the non-parabolicity and electron-hole asymmetry of energy-momentum dispersion in bilayer graphene. The tight-binding hopping amplitudes, t(0), t(1), and t(4), renormalized by electron-electron interaction are extracted from the chemical potential versus density dependence. A diverse set of electron-electron interaction driven phenomena were also clearly discerned at zero and high B-fields. We measure the gaps at integer fillings with orbital index N = 0, 1, and discuss about the dependence of the N = 0, 1 quantum Hall phases on the carrier density (or filling factor), E-field, and B-field.