What is Reversible Computing?
As the densities and switching speeds of our computational devices continue to increase exponentially, the amount of energy dissipated by these devices must remain at a certain level, otherwise economically impractical cooling apparatus is required. Conventional computers perform thermodynamically irreversible logic operations, that is, it is not possible to extrapolate prior machine states based solely upon information from future states. Information, in the form of bits, is erased. This bit erasure represents entropy, which is correlated to heat dissipation. As we employ increasingly advanced techniques to design our integrated circuits, the energy dissipation per logic operation has continually been falling. But around 2015 development will reach a fundamental barrier – the kT barrier – which represents a quantity of energy computed by multiplying the temperature of the computing environment (generally room temperature, or ~300 Kelvin) by Boltzmann’s constant. The only way to penetr
