Quantum-wire conductance manipulating by asymmetric quantum dot-molecules

Abstract

The electronic conductance at zero temperature through a quantum wire with side-attached asymmetric quantum dot-molecules (as a scatter system) is theoretically studied using the non-interacting Anderson tunneling Hamiltonian method. We show that the asymmetric configuration of QD-scatter system strongly impresses the amplitude and spectrum of quantum wire nanostructure transmission characteristics. It is shown that whenever the balanced number of chains-quantum dots in one molecule is substituted by unbalanced scheme, the number of forbidden mini-bands in quantum wire conductance increases to the sum of the number of quantum dots in two chains and thus the QW-nanostructure electronic conductance contains rich spectral properties due to appearance of the new anti-resonance and resonance points in spectrum. Considering the suitable inner gap between QD-chains in one molecule or outer gap between QD-molecules, can strengthen the amplitude of new resonant peaks in QW conductance spectrum. The proposed asymmetric-QD scatter system idea in this paper opens a new insight on designing quantum wire nanostructures for given electronic conductance.