Sub-Poissonian shot noise in graphene.
We calculate the mode-dependent transmission probability of massless Dirac fermions through an ideal strip of graphene (length L, width W, no impurities or defects) to obtain the conductance and shot noise as a function of Fermi energy. We find that the minimum conductivity of order e2/h at the Dirac point (when the electron and hole excitations are degenerate) is associated with a maximum of the Fano factor (the ratio of noise power and mean current). For short and wide graphene strips the Fano factor at the Dirac point equals 1/3, 3 times smaller than for a Poisson process. This is the same value as for a disordered metal, which is remarkable since the classical dynamics of the Dirac fermions is ballistic.
Tworzydło
J
J
Institute of Theoretical Physics, Warsaw University, Hoza 69, 00-681 Warsaw, Poland.
Trauzettel
B
B
Titov
M
M
Rycerz
A
A
Beenakker
C W J
CW