1School of Electronic and Information Engineering, Yangtze Normal University, Chongqing 408003 2College of Vanadium and Titanium, Panzhihua University, Panzhihua 617000 3College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108
Abstract:A parallel-coupled double quantum dot (PCDQD) system with two multi-quantum dot chains is designed. Conductance versus Fermi energy level is investigated utilizing the non-equilibrium Green's function approach. If two quantum dots are added on each side of the PCDQD system, additional Breit–Wigner and Fano resonances occur in the conductance spectra. If quantum dots are added on one side of the system, small Fano resonances can be observed in the conductance spectra. Adjusting the number of side-coupled quantum dots, the anti-resonance bands emerge at different positions, which makes the system applicable as a quantum switching device. Moreover, the $I$–$V$ characteristic curve presents the step characteristic and the width of the step decreases with increasing the number of side-coupled quantum dots.