▎ 摘　　要

The transport properties of a bilayer graphene are studied theoretically within a self-consistent Born approximation. The electronic spectrum is composed of k-linear dispersion in the low-energy region and k-square dispersion as in an ordinary two-dimensional metal at high energy, leading to a crossover between different behaviors in the conductivity on changing the Fermi energy or disorder strengths. We find that the conductivity approaches 2e(2)/pi(2)h per spin in the strong-disorder regime, independently of the short- or long-range disorder.