The study of metal-insulator transition in defected graphene nanotube by applying electric field: Quantum chaos approach

By employing quantum chaos theory, metal-insulator transition have been investigated in a single-walled graphene nanotube which is affected by vacancies based on the tight-binding Hamiltonian. Our obtained results indicate that applying electric field along the axis of the defected graphene nanotube caused metal to insulator transition. Using spectral and multifractal analysis, the threshold value of electric field is determined. The results show that the in the absence of electric field, the defected nanotube shows metallic behavior with Wigner distribution. By increasing the value of the electrical field, level spacing distribution changes from Wigner (delocalized) to Poisson (localized) distribution. Such that for the threshold value of the electrical field, Poisson level spacing sets in.