Introduction to carbon nanotubes
Carbon nanotube is a one-dimensional quantum material with a special structure (the radial dimension is on the order of nanometers, the axial dimension is on the order of micrometers, and both ends of the tube are basically sealed). Carbon nanotubes are mainly composed of carbon atoms arranged in hexagons to form coaxial circular tubes with several to tens of layers. Keep a fixed distance between layers, about 0.34nm, and the diameter is generally 2-20 nm. And according to the different orientations of the carbon hexagon along the axial direction, it can be divided into three types: zigzag, armchair and spiral. Among them, spiral carbon nanotubes have chirality, while zigzag and armchair carbon nanotubes have no chirality.