Introducing Coplanar Wire Crossing in Ternary Quantum Cellular Automata

One of the most recent issues in the field of Quantum Cellular Automata (QCA) is ternary QCA (tQCA). In the field of tQCA, some basic elements have been introduced. In spite of capabilities of this technology, such as encoding more than one bit in a single cell, there are some limitations in circuit design using tQCA cells. One of the most important shortcomings of tQCA compared to bQCA designs is the unavailability of coplanar wire crossing in tQCA. In fact, since there is no rotated (45-degree) cell in tQCA it would come to mind that it is impossible to have two crossing wires within a single layer. In this paper, based on our recent achievements in binary and ternary QCA, a novel coplanar wire crossing in tQCA is introduced. The proposed design has been analyzed theoretically and has been shown to work perfectly without the need for a two-layer circuit.