First-principles calculation of charge carrier mobility in graphene with absorbed magnetic molecules using complex band structure*

We compute charge carrier mobility in graphene as a function of temperature due to phonon scattering and scattering from adsorbed magnetic molecules from the complex band structure, using the Quantum Espresso suite. Carriers with finite lifetimes due to scattering may be represented by generalized Bloch states with complex energies. Our method determines the constant complex potential that must be added to a perfect crystal to induce the scattering effects seen in a crystal with defects, which we deduce from a series of complex band calculations. The mean scattering lifetime is computed from the imaginary part of this complex potential, and the carrier mobility is obtained from the scattering lifetime using the Boltzmann transport theory. Mobility is calculated for different magnetic molecule configurations to demonstrate that mobility measurements may be used to detect and distinguish different magnetic molecules.