Wagh M.D., Sun Y., Annampedu V.
Lehigh University, US
Keywords: architecture, comparison function, quantum-dot cellular automata
Quantum-Dot cellular automata (QCA) architectures represent the future of computing. But it can only implement an inverter and a three input majority gate directly. Consequently very few QCA architectures are available in literature. By fixing an input, one can also convert the majority gate to a 2 input AND or OR gate and thereby hope to build any required logic function. But such realizations are clearly very inefficient, both in terms of their size and speed. We present a direct and efficient QCA architecture for the comparison function. Our N bit comparison uses less than 4N three input majority gates and has an optimal O(log N) delay. We use recursion to obtain a tree-like structure which has clearly separated clocking zones. The efficiency of our architecture is due to the fact that the use of AND and OR gates, which have a poor realization in QCA technology, are limited to only the first level of the tree. Since comparison is an important component of many computations including realization of arbitrary Boolean functions, this work will have an impact in a multitude of applications.
Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2008: Microsystems, Photonics, Sensors, Fluidics, Modeling, and Simulation – Technical Proceedings of the 2008 NSTI Nanotechnology Conference and Trade Show, Volume 3
Published: June 1, 2008
Pages: 76 - 79
Industry sectors: Advanced Materials & Manufacturing | Sensors, MEMS, Electronics
Topic: Photonic Materials & Devices
ISBN: 978-1-4200-8505-1