Effective mass of electrons and holes in bilayer graphene: Electron-hole asymmetry and electron-electron interaction

This is the authors' abstract. We don't add key points for this paper.

Precision measurements of the effective mass m* in high-quality bilayer graphene using the temperature dependence of the Shubnikov--de Haas oscillations are reported. In the density range 0.7×10¹² $<$ n $<$ 4.1×10¹² cm^-2, both the hole mass mₕ* and the electron mass mₑ* increase with increasing density, demonstrating the hyperbolic nature of the bands. The hole mass mₕ* is approximately 20--30% larger than the electron mass mₑ*. Tight-binding calculations provide a good description of the electron-hole asymmetry and yield an accurate measure of the interlayer hopping parameter v₄=0.063. Both mₕ* and mₑ* are suppressed compared with single-particle values, suggesting renormalization of the band structure of bilayer graphene induced by electron-electron interaction.