Spin-polarized transport through doped nanotube junctions in presence of applied magnetic field

The effects of different spin orientations on transport through carbon nanotubes are studied, using a simple tight-binding model within the mean-field approximation. It turns out that, in the absence of external magnetic field, the mean-field ground states of both semiconducting and metallic nanotubes are antiferromagnetic. As regards electronic/transport properties, it is observed that the conductance characteristics of spin-up and spin-down carriers are separated, and a negative differential resistance (NDR) feature in the I-V characteristics is detected, when the system is subjected to external magnetic field. NDR is particularly interesting for a wide range of applications.