The Transport Properties And Shot Noise In Monographene Supperlattice

In this paper, we study the transport properties and shot noise in monographene supperlattice with the transfer matrix method. We respectively calculate transmission probability of four different potential barrier-structures structures in monogrephene, the results show that tansmission probability of electronic transmitting asymmetry step-barrier structures is biggest, and these results are also verified in the conductivities. Transmission probability is not only related to the barrier-structures form, but also the structure parameters. The narrower the width of potential barrier is, the bigger the transmission probability is. The conductivities exhibit oscillatory behavior, the conductivities of different potential barrier-structures form also present different characteristics.In the additional mangnetic field, the transmission curve changes, the shape of the transmission curve shifts left and it is no longer symmetric about the incident angle, the incident direction at which Klein tunneling occurs changes. Moreover, the oscillation of the conductivities becomes stronger but with a small magnitude oscillation. When the magnetic potential barrier is larger than the incident energy, the conductivity is zero.We also study the monographene supperlattice with periodic potentials. The results show that a new Dirac point appears in graphene supperlattice. In the point, the transport is almost forbidden, the conductivity gets the minimum, and the Fano factor approaches maximum 1/3. When the width of barrier equals the width of well, a new Dirac point appears at half of the barrier height. When the width of barrier is not equal to the width of well, the location of the new Dirac point changes, the locations of the conductivity minimum and Fano factor maximum also changed. The location of Dirac point is only related to the ratio of the width of barrier and the width of well, irrelevant to mangnetic field. When the incident energy is less than the Dirac point, the conductivities decrease and the Fano factor increase with the mangnetic field increasing.