Variation of Transmission Probability Spectrum with the Number of Dots in T-shaped Topology of Quantum Dot System

Abstract

We analyze the transmission coefficient for T-shaped configuration for quantum dot systems by increasing the number of dots side coupled to the active dot. Analytical expressions for the transmission coefficient have been calculated, in the presence of on-dot Coulomb interaction, using non-equilibrium Green function techniques. The higher-order Green functions containing Coulomb interaction terms have been decoupled using the mean-field approximation. Numerical results show a systematic variation in the transmission peak structure as the number of quantum dots side coupled to the active dot increases. The energy levels of dots available for electron transport have been identified in terms of the internal parameters of quantum dot systems. It is found that the number of transmission probability peaks is directly related to the number of dots in the T-shaped quantum dot system.