▎ 摘　　要

The authors investigated shot noise properties in the graphene-based double barriers. The shot noise with the Fano factor equal to 1/3 is found to occur at all conductance minimums including the Dirac point, which is a combined result of Klein tunneling, resonant tunneling, and quasiparticle chirality. The similarity in the shot noise suppression between graphene and diffusive metals is interpreted by the collective contribution from noiseless open channels and Poissonian-noise closed ones in the transmission spectra. It is also found that the Fano factor shows abrupt increase when the energy gap in the dispersion is larger than 1 meV. (c) 2007 American Institute of Physics.