I. Outline 1 II. Glossary 2 III. Definition of the subject and its importance 2 IV. Introduction 2 V. Cellular Automata 3 A. Reversible Cellular Automata 4 VI. Early proposals 4 VII. Definition 6 VIII. Models of QCA 6 A. Reversible QCA 6 B. Local unitary QCA 7 C. Block-partitioned and nonunitary QCA 7 D. Continuous-time QCA 8 E. Examples of QCA 8 IX. Computationally universal QCA 9 X. Modeling ...

complementary metal-oxide semiconductor (cmos) technology has been the industry standard to implement very large scale integrated (vlsi) devices for the last two decades. due to the consequences of miniaturization of such devices (i.e. increasing switching speeds, increasing complexity and decreasing power consumption), it is essential to replace them with a new technology. quantum-dot cellular...

J. Watrous introduced the notion of quantum cellular automata(QCA) and showed that any quantum Turing machine can be efficiently simulated by a QCA with constant slowdown in 1995. CA with quantum cells is well-formed QCA if and only if its global transition function is unitary. Generally quantumization of cells of a classical CA dose not make it become QCA, because usually classical CA dose not...

According to the well-known prediction made by Gordon Moore forty years ago, the increase in the number of transistors per square inch of integrated circuits doubles every 18 months. With this pace of miniaturisation it is to be expected that in the next five to ten years the integration will be at the nanometer scale [1]. Due to this fact, many researchers have focused on this problem. In the ...

BACKGROUND It is known that 9% to 31% of women and 4% to 14% of men with acute myocardial infarction have normal coronary arteries or nonsignificant coronary disease at angiography. These patients represent a diagnostic and therapeutic challenge. Multislice computed tomography (CT) can noninvasively identify the presence of coronary plaques even in the absence of significant coronary artery ste...

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 this paper we present a systematic view of Quantum Cellular Automata (QCA), a mathematical formalism of quantum computation. First we give a general mathematical framework with which to study QCA models. Then we present four different QCA models, and compare them. One model we discuss is the traditional QCA, similar to those introduced by Shumacher and Werner, Watrous, and Van Dam. We discus...

One-dimensional quantum cellular automata (QCA) consist in a line of identical, finite dimensional quantum systems. These evolve in discrete time steps according to a local, shift-invariant unitary evolution. By local we mean that no instantaneous long-range communication can occur. In order to define these over a Hilbert space we must restrict to a base of finite, yet unbounded configurations....

Quantum dot Cellular Automata (QCA) is one of the most popular nano-technology, with the potential for faster speed, lower power consumption and smaller size than the latest CMOS technology. One of the basic building blocks of QCA circuits is QCA wire. The conventional QCA wires require more cells and it has less polarization. In this paper, we have designed high polarized wires using minimum n...