Coherent mesoscopic transport through a quantum-dot embedded carbon nanotube ring threaded with magnetic flux

Abstract

We have investigated the coherent mesoscopic transport through a quantum-dot (QD) embedded carbon nanotube ring (CNR) by employing the nonequilibrium Green's function (NGF) technique. The Landauer–Büttiker-like formula is presented to calculate the differential conductance and current–voltage characteristics. Due to the interference of the electrons transporting in the two paths of CNR, the resultant conductivity of electron through the system is determined by the compound concrete structure of CNR–QD system. The tunneling current appears quantum behavior obviously in the small region of source-drain bias. The conductance is adjusted by the gate voltage Vg and the magnetic flux φ. The reversal resonance has been displayed versus the gate voltage, and it is symmetric about Vg for the type I CNR, but it is asymmetric for the type II CNR. The phase inverse oscillations are also presented for the different types of CNRs.