The Fantastical Promise of Reversible Computing� - Technology Review: "But there are a number of computing schemes that have the potential to work like this. Thapliyal and Ranganathan point in particular to the emerging technology of quantum cellular automata and show how their approach might be applied.
The beauty of this approach is that it has the potential to be dissipation-free. So not only would it use far less energy than conventional computing, it needn't lose any energy at all. At least in theory."