Lattice distortion and ferromagnetism in CaB6

NMR relaxation rate, T1−1, of the metallic carbon nanotube is discussed based on Tomonaga–Luttinger-liquid theory. It is found that the Coulomb interaction leads to increase of (T1T)−1 by a power law with decreasing temperature, T. The dependence on temperature of (T1T)−1 in the multi-wall nanotube (MWNT) is shown to be strongly suppressed by existence of the metallic shells in the MWNTs.