Chemical Potential and Quantum Hall Ferromagnetism in Bilayer Graphene
Abstract
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. We observe spin-to-valley polarized transitions for all half-filled LLs, as well as emerging phases at filling factors \nu = 0 and \nu = +-2. Furthermore, the data reveal interaction-driven negative compressibility and electron-hole asymmetry in N = 0, 1 LLs.
Keywords
Cite
@article{arxiv.1401.0659,
title = {Chemical Potential and Quantum Hall Ferromagnetism in Bilayer Graphene},
author = {Kayoung Lee and Babak Fallahazad and Jiamin Xue and David C. Dillen and Kyounghwan Kim and Takashi Taniguchi and Kenji Watanabe and Emanuel Tutuc},
journal= {arXiv preprint arXiv:1401.0659},
year = {2014}
}
Comments
21 pages, 4 figures; supplementary material includes four figures, and one table