A signal distribution grid for quantum-dot cellular automata

Coplanar wire crossing has been a major challenge for quantum-dot cellular automata systems since their development. Several possible solutions have been presented, but they have either relied on non-adjacent cell interactions or have required switching time that scales with the number of inputs or outputs. In this paper, the authors present a signal distribution grid that enables multiple parallel crossings, while doing so with only adjacent cell interactions, a constant time for signal distribution regardless of the number of inputs or outputs, and regularly shaped and contiguous clocking regions that will be relatively easier to fabricate. The utility of this device is demonstrated by the design of a one-bit full adder that meets all of the listed requirements.