Towards designing robust QCA architectures in the presence of sneak noise paths

Quantum-dot cellular automata (QCA) are attracting a lot of attention due to their extremely small feature sizes and ultra low power consumption. Several designs using QCA technology have been proposed. However, we have found that not all of the designs function properly. Further, no general design guidelines have been proposed so far. A straightforward extension of a simple functional design pattern may fail. This makes designing large scale circuits using QCA technology an extremely time-consuming process. We show several critical vulnerabilities in the structures of primitive QCA gates and QCA interconnects, and propose a disciplinary guideline to prevent any additional plausible, but malfunctioning, QCA designs.