Modelling Techniques for Simulating Large QCA Circuits

In the past several years, incredible advances in the availability of nano fabrication processes have been witnessed, and have demonstrated molecular-scale production beyond the usable limit for CMOS process technology. This has led to the research and early development of a wide-range of novel computing paradigms at the nanoscale; amongst them, quantum dot cellular automata (QCA). QCA is a nanoelectronic computing paradigm in which an array of cells, each electrostatically interacting with its neighbors, is employed in a locally interconnected manner to implement general purpose digital circuits. Several proof-of-concept QCA devices have been fabricated using silicon-on-insulator (SOI), metallic island devices operating in the Coulomb blockade regime, and nano-magnetics. In recent years, research into implementing these devices using single molecules has also begun to generate significant interest, and most recently, it was demonstrated that silicon atom dangling bonds (DBs), on an otherwise hydrogen terminated silicon crystal surface, can serve as quantum dots.