Spin and charge excitations in zigzag honeycomb nanoribbons: Effect of many body correlation

We have explored the electronic correlation effects on spin and charge excitation properties of honeycomb nanoribbons with zigzag edges. We adopt the theoretical formalism of many body configuration interaction to study the ribbon structures, modeled within Hubbard Hamiltonian. Enhanced correlation strength reduces the spin gap with increase in charge gap, indicating the possibilities of spin filtering applications. The charge gap behavior resembles with the observations obtained within one electron theories. Note that, we have neglected the scattering of electrons within different momentums to reduce the computational expense. Nevertheless, we confirm our observations in case of finite quantum dot structures that inherently take into account all such scatterings. (C) 2014 The Japan Society of Applied Physics