Effect of impurity doping on AFM magnetization in graphene: A tight-binding model approach

Abstract

We report here a tight-binding theoretical study of anti-ferromagnetism in graphene taking electron hopping up to third nearest neighbors. The graphene on substrate introduces inequivalence in the two sublattices of the honeycomb lattice. The on-site Coulomb interactions at two sublattices of graphene are treated within mean-field approximation and the electron occupancies at two sublattices include spin moments in opposite directions giving rise to anti-ferromagnetism in graphene. The AFM sublattice magnetizations are calculated by using Zubarev’s Green’s function technique and computed self-consistently for different ranges of Coulomb potential, substrate-induced gap and impurity concentrations. It is observed that [Formula: see text]-site magnetization is suppressed by [Formula: see text]-site impurity concentration, while [Formula: see text]-site magnetization remains unaffected. Similar effect has been observed at [Formula: see text]-site when doped with pentavalent dopant, while [Formula: see text]-site magnetization remains unaffected. Furthermore, substrate-induced AFM gap has also been observed at different ranges of temperature.