It probably wouldn't greatly affect the heat generation in a PC, unless the transistors could themselves be replaced with some superconducting alternative. Harnessing the efficiency from that would probably require that the computer be designed as a reversible computer. It would be its own research avenue.
Unfortunately, as soon as you actually use the result of the computation in any kind of practical manner as an output, you break reversibility, though you could make the heat production happen away from the computation.
The idea of reversible computing is that if you only add heat in a few instructions, you can have a much more economical computer. And magnetronics is a good candidate for implementing this, so yeah, computers that use a lot less power are an application too.
I haven't seen any reversible low power superconducting gate that can credibly operate at a high temperature - not because of the superconductor itself, but because of thermal noise. Again, I haven't read through the literature in this field for a while (and it wasn't that extensive either), but from what I recall what you're proposing is roughly as difficult as making a gate for a quantum computer, and you have to keep your system way colder than your critical temperature from that due to thermal noise. If you have any links for high temperature physically reversible logic gates I'm all ears.
I don't think you actually need reversibility if you don't discard the energy but return it to the power supply?
In other words, "reversibility", but you can actually pool the useless results together, you don't need to separate them later. Or so I read somewhere...
I might be wrong since I've studied this a long time ago, but from what I remember, in order to do that classically, you need to copy the output bits somewhere else before uncomputing your system and recovering the ancilia.
That's technically fine, as long as you have an infinite supply of stably initialized bits onto which to copy your result. Initializing those bits is going to be non-reversible in some way.
Computation inherently generates heat, but if you could make chips that release negligible amounts of heat, you would unlock the third dimension which would help with reducing signal length and enable computers to be significantly faster.
That this as a solution applicable to _personal_ computing is a bonus. The real benefit is in datacenters which could be made smaller, more efficient, and cheaper while simultaneously adding capacity.
