One interesting possibility for a future logic system is "quantum dot cellular automata", abbreviated QCA. |
Wolfgang Porod of the University of Notre Dame gave a talk on these devices at Ames workshop. His group has proposed configurations of cells, each of which is a collection of five electron sites arranged in an X, with two free electrons within the cell. |
According to their studies, configurations of these cells can propagate signals, invert signals, form majority vote logic, and thus can be formed to produce practical devices. |
The devices are semi-classical, semi-quantum, in that interactions within a cell can involve quantum tunneling, but interactions between cells involve only classical electromagnetic effects. |