Did you calculate the charge at each grid of the surface potential along the whole length of the CNT

Did you calculate the charge at each grid of the surface potential along the whole length of the CNT ? also what is the energry interval for the integration?

As I understood •the potential is solved from evanescent mode only for z direction The potential V(z) is only used for the two classical points in WKB tunneling. •You solve consistently to obtain pseudo-distribution function and then calculate the current