Electronic-transport properties of parallel double-ring systems

Abstract

We have studied a mesoscopic double-ring system connected in parallel and coupled to two electron reservoirs. The system is composed of one-dimensional ordered chains, and the two rings are threaded by magnetic fluxes ${\mathrm{\ensuremath{\Phi}}}_{1}$ and ${\mathrm{\ensuremath{\Phi}}}_{2}$, respectively. In the framework of the tight-binding model, the analytical and numerical calculations show that the transmission coefficient T is periodic in fluxes ${\mathrm{\ensuremath{\Phi}}}_{1}$ and ${\mathrm{\ensuremath{\Phi}}}_{2}$ with a period 2${\mathrm{\ensuremath{\Phi}}}_{0}$,${\mathrm{\ensuremath{\Phi}}}_{0}$=hc/e. For the system there are resonant states (T=1) and antiresonant states (T=0), the distribution of which displays a very remarkable symmetry. \textcopyright{} 1996 The American Physical Society.