Thermodynamic comparison of collinear two-dot QCA wires with traditional four-dot designs

摘要

Quantum-dot Cellular Automata (QCA) is a transistor-less computing paradigm which promises to extend the scaling of integrated circuitry past the physical boundaries of CMOS technologies. Many different physical implementations have been suggested and experimentally verified for QCA since its inception. Additionally, many computing architectures have been proposed extending the abilities of the QCA. However, the basic cell design, which consists of four logically active quantum-dots arranged in a rectangular pattern, has remained relatively unchanged during this progression. In QCA designs, the floor plan of the device layouts is dominated by communication paths, not logic operations. Additionally, the length of these communication paths largely relates to the expected correctness of the QCA devices because of thermal effects. For this reason, this paper proposes a new collinear two-dot QCA wire design which is more reliable than the traditional four-dot designs, operating at the same temperature and device dimensions. Furthermore, because fewer QCAs are required per length of communication path, the new design may have the effect of easing fabrication requirements.