Defect tolerance of QCA tiles

Quantum dot Cellular Automata (QCA) is one of the promising technologies for nano scale implementation. The operation of QCA systems is based on a new paradigm gen-erally referred to as processing-by-wire (PBW). This paper analyzes the defect tolerance properties of PBW when tiles are employed using molecular QCA cells. Based on a 3 × 3 QCA block, with different input/output arrangements, dif-ferent tiles are analyzed and simulated using a coherence vector engine. The functional characterization and polar-ization level of these tiles for undeposited cell defects are reported. It is shown that novel features of PBW are possi-ble due to spatial redundancy and QCA tiles are robust and inherently defect tolerant. Index words: QCA, defect tolerance, emerging technolo-gies. 1