Defect-tolerant adder circuits with nanoscale crossbars

Current manufacturing of molecular electronics introduces defects, but circuits can be implemented by including redundant components. We identify reliability thresholds for implementing binary adders in the crossbar approach to molecular electronics. These thresholds vary among different implementations of the same logical formula, giving a tradeoff between yield and circuit area. For instance, one implementation has at least 90% yield with up to 30% defects for an area 1.8 times larger than the minimum required for a defect-free crossbar.