54 research outputs found
Quantum transport of Dirac electrons in graphene in the presence of a spatially modulated magnetic field
We have investigated the electrical transport properties of Dirac electrons
in a monolayer graphene sheet in the presence of a perpendicular magnetic field
that is modulated weakly and periodically along one direction.We find that the
Landau levels broaden into bands and their width oscillates as a function of
the band index and the magnetic field.We determine the component
of the magnetoconductivity tensor for this system which is shown to exhibit
Weiss oscillations.We also determine analytically the asymptotic expressions
for .We compare these results with recently obtained results for
electrically modulated graphene as well as those for magnetically modulated
conventional two-dimensional electron gas (2DEG) system.We find that in the
magnetically modulated graphene system cosidered in this work,Weiss
oscillations in have a reduced amplitude compared to the 2DEG but
are less damped by temperature while they have a higher amplitude than in the
electrically modulated graphene system. We also find that these oscillations
are out of phase by with those of the electrically modulated system while
they are in phase with those in the 2DEG system.Comment: Accepted in PRB: 10 pages, 3 figure
Weiss oscillations in the electronic structure of modulated graphene
We present a theoretical study of the electronic structure of modulated
graphene in the presence of a perpendicular magnetic field. The density of
states and the bandwidth for the Dirac electrons in this system are determined.
The appearance of unusual Weiss oscillations in the bandwidth and density of
states is the main focus of this work.Comment: 8 pages, 2 figures, accepted in J. Phys.: Conden. mat
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