Boltzmann conductivity of ferromagnetic graphene with magnetic impurities

We investigate the electrical conductivity of spin-polarized graphene in the presence of short-ranged magnetic scatterers within the relaxation time approximation and the semiclassical Boltzmann approach. Spin-flip scattering of the itinerant electrons from the majority spin subband into the minority one results in a minimum in the electrical resistivity at a finite temperature. While this behavior is reminiscent of the renowned Kondo effect, it has an entirely different origin and differs from the Kondo effect in several aspects. In particular, unlike the Kondo effect, this is a single particle phenomenon, and it does not require antiferromagnetic coupling between the magnetic moments of impurities and spins of the itinerant electrons.

Figure 1

Current resistivity in up-spin (top panel) and down-spin (middle panel) channels, as well as the total resistivity (bottom panel) as a function of dimensionless chemical potential $\mu /h$, for different temperatures.

Figure 2

The dependence of current rates ${\Gamma }_s$ on energy. At $\varepsilon =sh$ the rate ${\Gamma }_s$ passes through a maxima and vanishes at $\varepsilon =-sh$.

Figure 3

The resistivity vs temperature for different doping ($\mu /h$) of magnetized graphene. The dependence exhibits a minimum at $k_{B}T\sim h$.