Chiral Conductivities of Nanotubes

Chiral conductivities of nanotubes are examined within the framework of the Boltzmann transport equation. Electron transport along a chiral trajectory is decomposed into current components along the tubule axis and its circumference. Within a constant relaxation time approximation, these components are derived from the expectation values of Fermi velocities by using the appropriate operators and the wave functions at the Fermi level obtained by first-principles calculations. As a typical example, the chiral current of a doped ${\mathrm{BC}}_2\mathrm{N}$ tubule is illustrated, and the strength of the induced magnetic field is discussed.