If the (n,m) index is a specific value (if n-m is a multiple of 3, or if n=m),the nanotubes are metallic. Metallic carbon nanotubes can carry more current per area than copper. For other classes of (n,m) indices (if n-m is NOT a multiple of 3), the nanotube is semiconducting. Semiconducting nanotubes can be switched on and off in circuits for memory or computing. Semiconducting carbon nanotubes have mobility higher than the best materials in the world. This has the potential to improve the speed and battery life of all electronic systems in the world. Of all possible combinations of (n,m), about 2/3 result in semiconducting nanotubes, and about 1/3 result in metallic nanotubes. Explore them in this app!