Effect of electric field on the electrical conductivity of defected carbon nanotube: Multifractal properties of the wavefunctions

A theoretical analysis of controllable metal-insulator transition is performed by carrying out a quantum chaos analysis for a single-walled carbon nanotube which is affected by topological Stone-Wales defect. Nanotubes have recently attracted attention as promising materials for flexible nanoelectronic devices. Individual topological Stone-Wales defects have been identified experimentally in carbon nanotubes (CNTs) and graphene. The findings reveal that defected CNT displays a gradual crossover from metal to insulator phase in a longitudinal electric field. By determining the threshold value of the electric field for metal-insulator transition, CNT may be used as a switch in electronic devices. Our results are obtained by calculating the singularity spectrum of a nearest-neighbor tight-binding model. Also, quantum chaos theory is used for obtaining a detailed understanding of a dynamic phase transition from delocalized states (chaotic) to localized states (Poisson). More interestingly, the appearance of negative differential resistance for pure CNT suggests potential applications in nanoelectronic devices.