Field-modulated Magnetic Properties of Carbon Nanotubes
Feng-Lin Shyu1*
1Physics, R.O.C. Military Academy, Kaohsiung, Taiwan
* presenting author:徐鳳麟,
The tight-binding model including curvature effects is used to study the effect of transverse electric field on the persistent currents of armchair and zigzag carbon nanotubes (ACNTs and ZCNTs) threaded by longitudinal magnetic field. With increasing field strength, ZCNTs could undergo zero-gap transitions, whereas metallic ACNTs are not affected. The current amplitude, without electric field, in a (m,m) ACNT is inversely proportional to m squared. However, for a (m,0) ZCNT, it is determined by the modulus of m with respect to three. Electric field could enhance the current amplitude of an ACNT, but could not change its magnetism. As for a ZCNT, both electric-field-distorted electronic states and zero-gap transitions determine a change in magnetism that is pronouncedly related with nanotube's geometry.

Keywords: Tight-binding model, Electric field, Persistent current, Carbon nanotube