Fault Tolerant Reversible Gate Based Sequential Quantum Dot Cellular Automata Circuits: Design and Contemplation

Abstract

In the era of quantum computing, Quantum Dot Cellular Automata (QCA) is a phenomenal technology which can produce low power, high speed and area efficient circuits. On the other hand, reversible logic is a promising paradigm which is used to construct low power circuits. This paper presents a design of a unique reversible gate based on QCA. This gate can facilitate the design of complex, cost efficient sequential circuits. The proposed gate is examined for various performance parameters such as realization of standard Boolean functions, cost function, energy dissipation and fault characterization. It is observed that the proposed gate exhibits superior performance as compared to the previously reported cost efficient designs in all the performance parameters. Furthermore, to evaluate the efficacy of the proposed QCA gate, reversible sequential latches are designed. The proposed structures of latches excel over the similar existing designs and have shown 50% improvement in latency, 58% improvement in effective cell area and around 70% improvement in cost function. The proposed latches are further investigated for temperature alterations to find the operating range of temperature for the circuits. The reversible QCA gate, proposed in this paper can be effectively used to design D latch, T latch, JK latch with improved performance. Hence, the proposed gate can find extensive scope in designing cost effective, low power, reversible sequential and combinational circuits.