Single-Electron Fault Tolerance in Quantum Cellular Automata Majority Gate

Abstract

Quantum cellular automata (QCA) is a promising paradigm that enables performing arithmetic and logic operations at the nanoscopic scale. The QCA utilizes the configuration of electric charges in molecular scale quantum-dots to encode binary information. Defects are very likely to occur at the nanoscale and impact the operation of QCA devices. We concentrate on a specific fault, which is caused by impurities in materials used in packaging devices. These defects may cause a single-electron to tunnel outside a QCA cell and lead to a single-electron fault (SEF). Cosmic rays may also lead to a SEF. The three-input majority gate is the primary device in the QCA paradigm. In this paper, the effect of redundant cells on the fault tolerance of the majority gate is studied in the presence of a SEF. We present figures based on the number of redundant cells, their positions, and the clock method, which are essential in designing SEF-tolerant devices.