Static magneto-polarizability of cylindrical nanostructures

The static polarizability of cylindrical systems is shown to have a strong dependence on a uniform magnetic field applied parallel to the tube axis. T his dependence is demonstrated by performing exact numerical diagonalizatio ns of simple cylinders (rolled square lattices), armchair and zig-zag carbo n nanotubes (rolled honeycomb lattices) for different electron-fillings. At low temperature, the polarizability as function of the, magnetic field has a discontinuous character where plateau-like region are separated by sudde n jumps or peaks. A one to one correspondence is pointed out between each d iscontinuity of the polarizability and the magnetic-field induced cross-ove r between the ground state and the first excited state. Our results suggest the possibility to use measurements of the static polarizability under mag netic field to get important, informations about excited states of cylindri cal systems such as carbon nanotubes.