Spontaneous Breaking of the Rotation Symmetry of Edge States in Zigzag Carbon Nanotubes

The electron edge states of carbon nanotubes with chiral index (N, 0) are studied. The total energy is lowered when the hydrogen ring at the end of the nanotube has distortion. The axial symmetry is thereby broken spontaneously. The prediction is supported via quantum chemistry simulation for (7,0) and (8,0) carbon nanotubes.