Design and Simulation of a 4:1 Multiplexer Using Quantum Rings

In this paper, a 4 to 1 multiplexer circuit is designed with four quantum rings where each ring is threaded by a constant magnetic flux  .  The quantum rings are connected to each other in series. They are attached symmetrically to two semi-infinite one-dimensional metallic electrodes, namely, source and drain, and four gate voltages are applied to the specific atomic sites of the quantum rings as four inputs of the multiplexer and also two other gate voltages are applied as the select lines. The Hamiltonian of the full system, i.e., the quantum rings, source and drain, are approximated by the tight-binding model, and the calculations are performed by using the Green’s function formalism for the strong and weak coupling between the quantum rings and the source and drain electrodes. The drain output current is calculated by using the Landauer formula as a function of the applied bias voltage. The truth tables of the multiplexer are obtained by assigning the 0 and 1 values to zero and non-zero drain current for different values of the data inputs on the basis of the values of the selected lines. It is found that this quantum structure behaves as a binary 4 to 1 multiplexer.