Effects of inter wall hopping on the electronic properties of double-wall carbon nanotubes

We study effects of changing inter wall hopping on the electronic and structural properties of ( n , n ) @ ( 2 n , 2 n ) and ( n , 0 ) @ ( 2 n , 0 ) double-wall carbon nanotubes using tight-binding model. We found by switching inter-wall interactions a valley opened in the ( n , n ) @ ( 2 n , 2 n ) local density of states, although both walls remained metallic. For the case of ( n , 0 ) @ ( 2 n , 0 ) where n is not multiple of 3 a semiconducting to metallic phase transition is found, while when n is multiple of 3 both inner and outer walls remained metallic.