A Theoretical Approach to Tunneling Processes in Quantum Structures

A theoretical framework for the electrical transport through quantum structures (QS) is proposed based on Keldysh Green's function. It is our purpose to develop a new analytic method which is applicable in the situation where the higher order effects of the elastic and the inelastic scattering processes are essential. We derive a general formula for the current through QS and find new components of co-tunneling current proportional to V 2 and V in addition to V 3 term at T =0 K resulting from electron correlation between different charge states.