Field-induced unraveling of carbon nanotubes

We investigate the disintegration mechanism of carbon nanotubes in strong electric fields using the ab initio density functional formalism. We find that nonotubes withstand fields up to 2 V/إ before they start unravelling carbon chains from the exposed edge, followed by field-induced fragmentation. We find this unraveling to be facilitated in negatively charged tubes, which have been shown to be efficient nano-scale electron emitters. We demonstrate that unraveling terminates at sites where adjacent walls are bridged by a covalent bond.