Chemical Potential and Quantum Hall Ferromagnetism in Bilayer Graphene

Understand

Bilayer graphene has a unique electronic structure influenced by a complex interplay between various degrees of freedom.

• We probe its chemical potential using double bilayer graphene heterostructures, separated by a hexagonal boron nitride dielectric.
• The chemical potential has a non-linear carrier density dependence, and bears signatures of electron-electron interactions.
• The data allow a direct measurement of the electric field-induced bandgap at zero magnetic field, the orbital Landau level (LLs) energies, and the broken symmetry quantum Hall state gaps at high magnetic fields.