The nice thing about quantum computers is that they’re mostly reversible, ie swaps can always be done with zero energy, until you make a measurement. Once you do, you have to pay the energy cost, which I showed in the last comment. We don’t need anything else here.
The nice thing about quantum computers is that they’re mostly reversible, ie bit erasures can always be done with zero energy,
You seem confused here—reversible computations do not, can not erase/copy bits, all they can do is swap/transfer bits, moving them around within the computational system. Bit erasure is actual transference of the bit entropy into the external environment, outside the bounds of the computational system (which also breaks internal quantum coherence from what I recall, but that’s a side point).
Replication/assembly requires copying bits into (and thus erasing bits from) the external environment. This is fundamentally an irreversible computation.
The nice thing about quantum computers is that they’re mostly reversible, ie swaps can always be done with zero energy, until you make a measurement. Once you do, you have to pay the energy cost, which I showed in the last comment. We don’t need anything else here.
Thanks to porby for mentioning this.
You seem confused here—reversible computations do not, can not erase/copy bits, all they can do is swap/transfer bits, moving them around within the computational system. Bit erasure is actual transference of the bit entropy into the external environment, outside the bounds of the computational system (which also breaks internal quantum coherence from what I recall, but that’s a side point).
Replication/assembly requires copying bits into (and thus erasing bits from) the external environment. This is fundamentally an irreversible computation.