Modeling carrier mobility in graphene as a sensitive probe of molecular magnets

Abstract

Carrier mobility in graphene on a GaAs substrate and its change due to the adsorption of molecular magnets, ${\mathrm{Mn}}_{12}$ and $[{\mathrm{Mn}}_{3}{]}_{2}$, on the surface of graphene, is calculated from first principles. Phonon limited mobility is also calculated for comparison. For ${\mathrm{Mn}}_{12}$ adsorption on graphene, the mobility is compared for different organic ligands of ${\mathrm{Mn}}_{12}$ $(\text{\ensuremath{-}}\mathrm{H}, \text{\ensuremath{-}}{\mathrm{CH}}_{3}, \mathrm{and} \text{\ensuremath{-}}\mathrm{CH}{\mathrm{Cl}}_{2})$, while for $[{\mathrm{Mn}}_{3}{]}_{2}$ dimers, the mobility is calculated for different linkers that yield the ferromagnetic and anti-ferromagnetic configurations of $[{\mathrm{Mn}}_{3}{]}_{2}$, as well as for different orientations of the molecule. Significant changes in carrier mobility due to the adsorption of the molecules and due to differences in linkers suggest mobility measurement as a possible sensitive probe of magnetic molecules.