exactly invariant. To be more specific, it is important to note that, in real situation the experimentally achievable rings have typical diameters within the range 0 . 4-0 . 6 µ m. In such a small ring, unrealistically very high magnetic fields are required to produce a quantum flux. To over- come this situation, Hod et al. have studied extensively and proposed how to construct nanometer scale devices, based on Aharonov-Bohm interferometry, those can be operated in moderate magnetic fields [32–35]. 5 current can be regulated in the case of two rings by tun- ing the phase difference δ between the fluxes φ$_{1}$ ( t ) and φ$_{2}$ ( t ). The whole modulation action is based on the cen- tral idea of quantum interference effect in presence of flux φ in ring shaped geometries. We adopt a simple tight-binding framework to illustrate the model and all the calculations are done using single particle Green’s function formalism. Our exact numerical results provide two-terminal conductance and current which clearly de- scribe the essential features of current modulation. Our analysis can be used in designing tailor made nano-scale electronic devices. In the present paper we have done all the calcula- tions by ignoring the effects of the temperature, electron- electron correlation, etc. Due to these factors, any scat- tering process that appears in the mesoscopic ring would have influence on electronic phases, and, in consequences can disturb the quantum interference effects. Here we have assumed that, in our sample all these effects are too small, and accordingly, we have neglected all these factors in this particular study. Throughout our work, we have described all the essen- tial features of current modulation for two different ring sizes. In circuit configuration I, we have chosen a ring with total number of atomic sites N = 20. 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