Intrinsic magnetoresistance of single-walled carbon nanotubes probed by a noncontact method

The intrinsic magnetotransport effect of the single-walled carbon nanotube (SWNT) has been observed by the cavity perturbation technique, which is a noncontact method for evaluating transport properties. The inverse Q factor of the cavity resonator, which corresponds to the resistance of the sample, shows a linear increase as a function of the magnetic field. The angular and tube diameter dependence of oriented SWNT thin films, and measurements using sorted SWNTs reveal that the observed positive magnetoresistance is due to the Aharonov-Bohm effect of metallic nanotubes.