Properties of electron transmission through serially connected hexagonal nanorings

Transmission properties are investigated for a system of two-branch nanorings with two quantum dots per branch. The rings are connected serially by a linear segment, creating a chain of rings. Applying a tight-binding Hamiltonian method, the electron transmission properties are primarily studied. Multiple system parameters are varied to study their effects on the transmission spectrum. These parameters include the coupling to the leads in and out of the system, the coupling between rings, and the total number of rings in the system. Each of these parameters affect the transmission bandgap, the resonant transmission, and the number of resonance peaks per transmission band. By tuning the system-leads coupling to a particular value which produces a coupling match between the periodic ring system and the source and drain leads, a combination of interference and resonance effects results in a broad range of transparency, wherein the system shows full transmission over a range of energy values, independent of the number of rings in series.