Magnetic superlattice and finite-energy Dirac points in graphene

Luca Dell'Anna, Alessandro De Martino
2011 Physical Review B  
We study the band structure of graphene's Dirac-Weyl quasi-particles in a one-dimensional magnetic superlattice formed by a periodic sequence of alternating magnetic barriers. The spectrum and the nature of the states strongly depend on the conserved longitudinal momentum and on the barrier width. At the center of the superlattice Brillouin zone we find new Dirac points at finite energies where the dispersion is highly anisotropic, in contrast to the dispersion close to the neutrality point
more » ... h remains isotropic. This finding suggests the possibility of collimating Dirac-Weyl quasi-particles by tuning the doping.
doi:10.1103/physrevb.83.155449 fatcat:zfheu6nnmbfghbdpipgfkqf2gq