A Universal Gate for Combinational Design of QCA Circuits

As an emerging technology, Quantum-dot Cellular Automata (QCA) has been extensively analyzed in the technical literature for implementing logic circuits; in this technology, the basic combinational circuit is the majority voter with three inputs. In this paper, the design of a logic gate which implements any combinational function of at most three input variables is presented. This type of gate is generally referred to as a universal gate and is often used as logic resource in array structures such as FPGAs. This paper investigates a logic characterization of the universal gate using two different techniques found in the technical literature: AND/OR-based synthesis and MV-based synthesis. Important design features of the gate (such as the utilization of the majority voting function or MV and inverters) and design issues revolving around signal routing of the input signals are presented along with the introduction of non-blocking interconnect circuit in this paper to extend the logic capabilities. Keywords-component QCA, emerging technologies, quantum computing, universal gate.