Quantum-dot Cellular Automata (QCA) as a nanoscale transistor-less device technology offers distinguishing advantages over the limitations of CMOS circuits. While more than 2 decades of design progress have been achieved with QCA, a comprehensive composition approach for the layout design in this technology is needed. In this study, the Priority-Phased Decomposition-Driven (PPDD) QCA logic desi...

Quantum Cellular Automata (QCA) present one of the many emerging computational nanotechnology paradigms. It uses the arrangements of individual electrons, instead of currents and voltages, to encode binary information. Note a QCA cell consists of four quantum dots located at the corners of a square. This tutorial paper provides an introductory material on the design and testing of combinational...

We will prove the existence of a universal quantum cellular automaton. Such qca are defined as the quantum-mechanical pendant of classical one-dimensional cellular automata. As is the case with quantum Turing machines, the well-formedness restriction plays an important role. It will be shown that every proper qca obeys a local constraint which is comparable with the ‘inverse neighborhood’ of cl...

Today, the use of CMOS technology for the manufacture of electronic ICs has faced many limitations. Many alternatives to CMOS technology are offered and made every day. Quantum-dot cellular automata (QCA) is one of the most widely used. QCA gates and circuits have many advantages including small size, low power consumption and high speed. On the other hand, using special digital gates called re...

Quantum-dot cellular automata (QCA) is a novel and potentially attractive technology for implementing computing architectures at the nano-scale. By applying a set of simple layout rules, arbitrary circuits can be made using QCA cells. In this work, we describe the design and layout of a QCA random access memory (RAM), showing the layout of individual memory cells, as well as, a suggested layout...

Quantum-dot Cellular Automata (QCA) is one of the candidates among future nanoelectronic computing technologies. QCA is based on cells of coupled quantum dots. The QCA cells have features on the very low nanometer scale, much smaller than the present state of art size of the smallest transistor. The physical interaction between neighbouring cells has been exploited in the implementation of logi...

The most important mathematical operation for any computing system is addition. An efficient adder can be of greater assistance in designing of any arithmetic circuits. Quantum-dot Cellular Automata (QCA) is a promising nanotechnology to create electronic circuits for computing devices and suitable candidate for next generation of computing systems. The article presents a modest approach to imp...

Improved layout of QCA(quantum-dot cellular automata)based PLA (programmable logic array) that enhance the defect tolerance is proposed, in order to develop next generation circuit technology that replace the conventional CMOS technology. We analyze which QCA device (quantum-dot cell) limits the defect tolerance of the AND/OR plane cell of the QCA-PLA by using QCA circuit simulator or QCADesign...

Quantum-dot Cellular Automata (QCA) is an emerging and promising technology that provides significant improvements over CMOS. Recently QCA has been advocated as an applicant for implementing reversible circuits. However QCA, like other Nanotechnologies, suffers from a high fault rate. The main purpose of this paper is to develop a fault tolerant model of QCA circuits by redundancy in hardware a...

In The Comparative Method, Ragin (1987) outlined a procedure of Boolean causal reasoning operating on pure coincidence data that has since become widely known asQCA (Qualitative Comparative Analysis) among social scientists. QCA—also in its recent forms as presented in Ragin (2000, 2008)— is designed to analyze causal structures featuring no more than one effect and a possibly complex configura...