Transport in robust fullerene-tube heterostructure transistor

A fullerene-tube (nanotube) heterostructure produces a robust resonant-tunneling transistor when leads of metallic nanotubes surround a short barrier of semiconducting nanotube and when a close metallic gate regulates the energy position of the resonant level trapped in this barrier region. We combine electron-structure calculations with a conserving nonequilibrium Green function study for the interacting transistor transport to describe the predicted current-switch, transistor and negative-differential amplification effects. The potential for electron dynamics inside the central nonconducting barrier region is calculated in the presence of screening to characterize the electrostatic-gate control of the resonant-energy levels. A nonequilibrium Green function calculation determines the gate-dependent nonlinear current and quantifies the transistor effect also in the presence of scattering. Finally, we identify conditions when conservation laws ensure important transistor robustness, i.e., insensitivity to scattering and room-temperature operation.