Disorder effects in the magnetic oscillations on graphene with Zeeman splitting

J. S. ARDENGHI; P. JASEN; E GONZÁLEZ; F. ESCUDERO; A. JUAN

Pasteum

Congreso; GM-2016 International Conference: Graphene and related materials, properties and applications; 2016

Physics Department of the University of Salerno

The aim of this work is to describe the electronic and magnetic properties ofgraphene in a constant magnetic field in the long wavelength approximation withrandom binary disorder, by applying the coherent potential approximation tosolve the self-energy. Taking into account the Zeeman effect, the electronicdensity of states for each spin is found and its contributions to eachsublattice and each valleys subspaces are obtained. The Zeeman splittingintroduces a shift in the DOS, which in turn creates a spin polarization. Bychanging the magnetic field, the de Haas van Alphen oscillations (dHvA) arefound and the total magnetization, which is proportional to the difference ofeach spin magnetization, is obtained, where it is shown how the Zeeman splittingcreates changes in the dHvA oscillations. Finally, the impurities create peaksand dips in each spin magnetization, which are enhanced in the totalmagnetization, showing that this behavior is a direct consequence on the way inwhich the Fermi level crosses the impurity bands. In turn, the crossover betweenthe Zeeman energy and the pseudospin-Landau coupling energy is studied, showingthat a transition to a constant magnetization is obtained for a critical valueBC, where the difference of both energies is the largest. These theoreticalresults can be used to describe Fermi surfaces of doped graphene, by taking intoaccount the effects of the impurities in the magnetization and how these effectsare enhanced by the Zeeman effect. In turn, the impurity effects on the totalmagnetization for small values of B can be used for spintronic applications.