Abstract

Quantum Dot Cellular Automata has arisen as a promising nanotechnology for the enactment of high-density and ultra-low power digital circuits beyond conventional CMOS Technology. In this exertion a 4:1 QCA-based Multiplexer is designed using region-based interaction methodology and four-phase clocking scheme. The proposed design utilizes total 45 cells with area occupancy of 0.006 µm2 with latency of one clock cycle. To authenticate the design methodology, an alternative 40-cell layout design for 4:1 Multiplexer was also implemented so as to confirm the precision of the methodology. Simulation and functional verification were executed by using QCA Designer 2.0.3, while energy dissipation analysis was carried out using QCA Designer-E under Coherence Vector Energy Simulation engine at an operating Temperature of 1K by exploiting both Euler’s and Runge-Kutta Method numerical methods. The proposed design exhibits a total energy dissipation of 1.62×10-2 eV and an Average energy dissipation of 1.48×10-3 eV per cycle using Euler’s Method while Runge-Kutta Method reports total energy dissipation of 1.74×10-2 eV and average energy dissipation of 1.58×10-3 eV per cycle. The designed layout attained a cell omission tolerance of 66.67%, while misalignment analysis confirmations functional rates of 87.5%,87.5% and 75% for displacement values of 5nm,10nm, and 15nm. Furthermore, the correlation between kink energy and fault tolerance executed in this work confirms that regions with stronger electrostatic coupling exhibit improved robustness against fabrication-induced defects. Comparative analysis also shows better improvement in terms of energy dissipation and other performance parameters as compared to existing multiplexer designs, which indicates the suitability of the proposed architecture for reliable nanoscale QCA implementations.