Specific heat of doped armchair and zigzag carbon nanotubes

We study the temperature behavior of electronic specific heat of metallic carbon nanotubes in the context of Holstein model Hamiltonian. Greenʹs function approach has been implemented in order to calculate the electronic contribution to the specific heat of the compound. Second order perturbation theory has been used to obtain interacting Greenʹs function of model Hamiltonian. The results show a monotonic increasing behavior for specific heat with temperature for both armchair and zigzag carbon nanotubes. Furthermore, the effect of various electronic concentrations and the electron–phonon coupling strengths on the specific heat has been investigated.