Nanotechnologies, such as resonant-tunneling devices (RTDs), quantum cellular automata, single electron transistors, atom relays, refined molecular relays, carbon nanotube transistors, etc., have seen significant advances in the last few years. They offer orders of magnitude improvements in chip density, performance and power consumption, making many as-yet undreamed-of applications feasible. However, comprehensive circuit analysis/synthesis methodologies and tools have not yet been developed for any nanotechnology. Such tools are urgently needed in order to realize their potential. In this proposal, the investigators will target RTD-based nanotechnology, which has already shown industrial promise. Specifically, we will develop an electronic circuit design optimization environment, and techniques for circuit design, logic synthesis, testing and fault tolerance for this nanotechnology.