Date of this Version
PHYSICAL REVIEW B 84, 085408 (2011); DOI: 10.1103/PhysRevB.84.085408
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 m*h and the electron mass m*e increase with increasing density, demonstrating the hyperbolic nature of the bands. The hole mass m*h is approximately 20–30% larger than the electron mass m*e . 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 m*h and m*e are suppressed compared with single particle values, suggesting renormalization of the band structure of bilayer graphene induced by electron-electron interaction.