Pure and Applied Chemistry

Abstract: A Boolean logic, nonreversible computing machine should, in principle, be capable of 10 18 bit operations per second at a power consumption of 1 W. In order to build such a machine that can even approach this benchmark for efficiency, the development of a robust quantum-state switch capable of ambient operation, as well as a bottom–up manufacturing technology, will be necessary. My group, in collaboration with Hewlett Packard, has developed much of the architecture for such a machine, which we call a chemically assembled electronic nanocomputer (CAEN). More recently, in a collaborative effort with Fraser Stoddart's group at UCLA, we have begun to build it. The fundamental unit of the machine is a field-programmable molecular switch, and the fundamental architecture is a hierarchical organization of wire/switch lattices called crossbars. Electronically, singly configurable molecular-based switch devices based on rotaxane molecular compounds have been fabricated in high yield. These switches were used to construct simple molecular-based logic structures and read-only memory elements.