# How to destroy/destabilize a structure that's been flux-pinned?

Flux pinning (also known as quantum locking): https://en.m.wikipedia.org/wiki/Flux_pinning

This technique has been discussed on this site before as a method for creating nearly indestructible super-materials that can absorb as much energy from violent impacts as you can feed into the electromagnetic field holding it together (this same field also necessarily makes it impervious to the effects of electromagnetic pulses or fields weaker than its own). But of course having a truly indestructible super-material is boring, and it becomes even more boring if the only way to beat it is "hit it harder until it breaks".

So, since I'm not an expert in physics or material science, I'm asking those more knowledgeable than I if a method exists to destroy something reinforced with flux pinning/quantum locking that doesn't involve bashing it with repeatedly more force like an angry caveman. Can it be destabilized with a more fine-tuned, technical approach or is it basically just always going to be a matter of bashing your head against the quantum-locked wall until it breaks?

## 2 Answers

The pinned object needs to be a type-II superconductor for flux pinning to work. The simplest way to stop it being a superconductor is to heat it above its critical temperature. Anything from a spray of hot water on upwards should be able to do that.

You could also apply an additional magnetic field, taking the total field strength above the critical level $H_{c2}$, but applying heat is usually going to be simpler.

• Won't a counter magnetic field to negate (or at least weaken enough to be useless) the primary field be easier? (I'm guessing the superconducters will be treated to be able to absorb/displace a lot of heat to stay useful.) – Tezra Oct 28 '16 at 16:06
• So even if it could handle the explosive force of the blast, a nuke WOULD work as a means of destroying or disrupting a large flux-pinned structure? – Z.Schroeder Oct 28 '16 at 16:23
• @Z.S: Yup. The first thing that arrives from a nuke is the electromagnetic radiation, which will heat up anything nearby a lot. Active cooling systems work on a very different timescale, of tenths of a second, rather than microseconds. – John Dallman Oct 28 '16 at 16:31

An outside magnetic field will perturb the member being pinned, causing the feedback to restore it in the same manner as a physical blow. But it also induces its own compensation in the superconductor, and you can take advantage of this to break things.

There is a time difference due to speed of light delay, and geometric positions of things relative to the disrupter. The superconductor does not act instantly but has its own finite stiffness in its reaction.

In GEB, the Tortoise gets interested in making records to break record players, and gets in a competition with another character who tries to build a player immune to such attacks. It’s shown that a targeted attack must always exist.

The disrupter will induce high-frequency perturbations designed to resonate and force the natural correction mechanism to form part of a positive feedback loop. The structure tears itself apart if the superconductor doesn’t fail first.