Quantum transport in bilayer graphene and its heterostructures

Bilayer graphene represents an attractive two-dimensional electron system for electron physics and potential device applications. In this dissertation, we present a comprehensive experimental study of electron transport in bilayer graphene, and its heterostructures. Using double bilayer graphene heterostructures, separated by a hexagonal boron nitride dielectric, we map the chemical potential in the bottom bilayer employing the top bilayer as a resistively detected Kelvin probe. The measured chemical potential-density dependence at zero magnetic field shows signatures of electron-electron interactions, along with electron-hole asymmetry. We provide an in-depth investigation of quantum Hall (QH) ferromagnetism in bilayer graphene, revealing new QH phases at filling factors ν = 0 and ν = ±2, predicted to possess coherent Landau level superpositions, spin-to-valley polarized transitions, as well as interaction-driven negative compressibility. We also study the interactions between the two bilayers, where the interlayer spacing is smaller than the intra-layer particle spacing by probing frictional drag, a phenomenon in which charge current flowing in one (drive) layer induces a voltage drop in the opposite (drag) layer. At temperatures (T) lower than 10 K, we observe a large anomalous negative drag near the drag layer charge neutrality, which increases dramatically with reducing T, strikingly becoming comparable to the layer resistivity at the lowest T = 1.5 K. A comparison of the drag resistivity and the drag layer Peltier coefficient suggests a thermoelectric origin of the drag.Electrical and Computer Engineerin