Spin-Polarized Transport in Carbon Nanowires Inside Semiconducting Carbon Nanotubes

A first-principles approach combined with none-equilibrium Green’s function method is used to investigate the spin-polarized transport properties of a kind of all-carbon composite: carbon nanowires (CNW) in the core of single-walled carbon nanotubes. Our results indicate that if the CNW density is not too high, spin-polarized transmission spectra are obtained resulting from the two majority spin bands induced near the Fermi level. With the bias voltages applied, spin-polarized current and negative differential resistance (NDR) appear. The appearance of NDR can be analyzed from the mismatch of the energy bands in the left and right leads due to external bias voltages. Other factors that influence the degree of spin-polarization are also discussed. 1