Simulation-based design of modular QCA Circuits
ABSTRACT The design of quantum-dot cellular automata (QCA) circuits and systems is still in an infancy stage; a modular technique which relies on building blocks referred to as tiles, is proposed in this paper. This approach consists of first analyzing the logic capabilities of the basic tiles (inclusive of simulation) followed by logic mapping and connecting the tiles to form the desired circuit. The 3×3 QCA grid is presented as an example of basic block. Five types of tiles can be constructed using the 3×3 grid. A logic characterization of these tiles is presented by using a coherence vector simulation engine. It is shown that the 3×3 grid is not only area efficient, but it also offers versatile logic operation. Various QCA circuits designed using the tile-based method are presented and compared with conventional gate-based design as well as the SQUARES methodology.
- SourceAvailable from: Geza Toth[show abstract] [hide abstract]
ABSTRACT: A device representing a basic building block for clocked quantum-dot cellular automata architecture is reported. Our device consists of three floating micron-size metal islands connected in series by two small tunnel junctions where the location of an excess electron is defined by electrostatic potentials on gates capacitively coupled to the islands. In this configuration, the middle dot acts as an adjustable Coulomb barrier allowing clocked control of the charge state of the device. Charging diagrams of the device show the existence of several operational modes, in good agreement with theory. The clocked switching of a single electron is experimentally demonstrated and advantages of this architecture are discussed. © 2000 American Institute of Physics.Applied Physics Letters 07/2000; 77(2):295-297. · 3.79 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Quantum Cellular Automata (QCA) is a new technology that replaces current flow as an information carrier by coulombic interactions of electrons within confined configurations. Prior work has investigated its potential as very dense logic. This paper uses a defining characteristic of such devices, namely pipelining that occurs even at the wire level, as the mechanism for memory structures that are formed recursively, rather than as conventional CMOS arrays, and hold the potential for extremely dense storage with embedded processing capabilities.03/2002;
Conference Proceeding: Quantum cellular automata: the physics of computing with arrays of quantum dot molecules[show abstract] [hide abstract]
ABSTRACT: We discuss the fundamental limits of computing using a new paradigm for quantum computation, cellular automata composed of arrays of coulombically coupled quantum dot molecules, which we term quantum cellular automata (QCA). Any logical or arithmetic operation can be performed in this scheme. QCA's provide a valuable concrete example of quantum computation in which a number of fundamental issues come to light. We examine the physics of the computing process in this paradigm. We show to what extent thermodynamic considerations impose limits on the ultimate size of individual QCA arrays. Adiabatic operation of the QCA is examined and the implications for dissipationless computing are exploredPhysics and Computation, 1994. PhysComp '94, Proceedings., Workshop on; 12/1994