  We investigate many-body effects near the edge of a single-walled carbon
nanotube and find it turns magnetic with quantized edge moment solely depends
on the chiral vector, i.e. the topology of the carbon nanotube. The
distribution of the edge moment reveals an approximate supersymmetry even in a
realistic model. Our findings demonstrate crucial importance of the interplay
between the electronic correlation and the edge morphology. The edge moment
provides an excellent candidate for nanomagnet farbrication which has potential
applications in biological and chemical detections, and in spintronics.
