Charging Toward Superconductivity

This is one of those mad Ideas I originally had decades ago, but somehow didn't think of posting it here until now.

Most everyone who knows something about electricity knows that when electrons flow through a wire, there is usually some resistance to their motion, which we can compare to (or analogize as) "friction".

The phenomenon of superconductivity is thought to be the result of electrons behaving in a very special way. Pairs of them act together to, basically, cancel out each other's friction, as they move through a conductor. They are called "Cooper pairs" after the physicist who pulled that idea out of Quantum Mechanics.

Cooper pairs can be broken up by heat, and thus many superconductors only behave as such at extremely low temperatures (mostly below the temperature at which hydrogen gas freezes solid).

It came as quite a suprise in the 1980s when certain materials (mostly copper-oxide ceramics) demonstrated superconductivity at liquid-nitrogen temperatures. The mystery yet remains to be solved, regarding how Cooper pairs can still stay together as pairs, at that temperature. The evidence so far suggests that there is some special aspect of the physical structure of the material, that assists them.

Anyway, I may be mistaken, but I get the impression that a Cooper pair is a "lower-energy" state, for a pair of electrons, than when they are not paired. That means electrons would prefer to pair-up if only there wasn't so much thermal energy typically available at room temperature, to discourage them from doing that.

But it **also** means that a completely different approach toward achieving superconductivity might be possible.

Consider the concept of "pressure". It tends to cause things to occupy less space, whenever it is possible for those things to do that. A simple/common example is a "pressure cooker", which forces water to stay liquid at a temperature higher than its boiling point at ordinary atmospheric pressure.

Well, water, as a liquid, occupies something like 1/1600 the space of water-as-a-gas. Also, liquid water is typically a "lower-energy state" than steam. So, what pressure can do is force water to stay in the lower-energy state, despite the temperature of the water being such that it might "prefer" to be in the gaseous state.

I'm guessing that we can apply that principle toward making superconductivity work at higher temperatures. All we need is the right sort of "pressure".

So, start with a loop of metal. If current flowed in it, we would have a "closed" electric circuit. If it was a superconducting metal, it would generally be surrounded with liquid helium, to actually be used as a superconductor. It is my understanding that special care is taken, at the point where a superconducting wire interacts with a non-superconducting wire, to ensure that the superconducing wire **stays** superconducting.

One way to do that invovles "induction". If the electric current in either wire changes, then it will be associated with a magnetic field that also changes, and which can induce a similar changing current to flow in the other wire. So, the wires don't have to touch, for power to be transferred from one to the other. (Note: not all superconductors will cooperate as easily as I've just described; they tend to repel magnetic fields.)

That separation of electrical circuits is very important for this Idea!

What we want to do is start with our isolated "superconducting" loop of material, regardless of whether or not it is actually a superconductor when we do the next step --which is to give it a very strong negative electric charge. Basically, we are pressurizing the quantity of electrons within that closed and isolated loop of wire.

Which means, to the extent that Cooper pairs represent a lower-energy state for electrons, that pressure should encourage their formation.

To find out, we now cool the wire down toward the "transition" temperature at which we would expect it to become a superconductor. But while cooling it, we test it, to see if the transition temperature has changed. Will the loop of wire become a superconductor at a higher temperature than before?

To be determined by Experiment! --And, preferably, by a lot of experiments, to see what degree, if any, charging up a wire enhances its ability to superconduct. Maybe this method alone can let us achieve the dream of room-temperature superconductivity. (More likely, we would combine it with the highest-temperature uncharged superconductor that we can make.)

========Added March 20, 2012
Per an annotation, I should mention that "voltage" is the term normally associated with electrical "pressure". A Van de Graaff generator can easily apply a pressure of 400,000 volts to an object, and a Cockcroft-Walton "voltage multiplier" can go even higher, by using alternating current and diodes to build up a static charge. Keep in mind that such voltages can require lots and lots of insulation, to ensure the charged material retains that voltage-pressure!

I also neglected to mention that simply by testing for the ability of a material to exclude a magnetic field (typically indicated by the initiation of "magnetic levitation"), that is another way to determine if a material has become superconductive.