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Comment by dontwearitout | Hacker News Reader

Room temperature, but 1GPa pressure (or 145037 psi).

An exciting step forward if it's reproducible, but not useful commercially. I'd rather see breakthroughs in theoretical understanding; superconductivity in these regimes is still very poorly understood to my knowledge.

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A woodworking clamp with a handle in line with the screw will generate about 400lbs of force. That’s a reasonable model for how much axial force you will be able to exert with a screwdriver handle and beefy threaded screws. To get 150000 psi you have to squeeze something .0027 square inches, or 1.7mm^2, leave some room for edges and let’s work with 1mm^2.

I’m not sure what interesting things can be done with this superconductor in 1mm^2, but squeezing the anvil isn’t outrageous.

For perspective, TSMC will put 150 million transistors in that area. I kind of suspect that integrated circuits might flow at this pressure, so that might not be the application, but a superconducting ground plane and power plane would be interesting.

Edit: Wait, maybe that’s just a giant capacitive load on all the signals. Do something smarter.

Never mind the silicon, that's about at the compressive strength of tool steel and significantly more than that of stainless.

I'm beyond my expertise, but silicon crystal's compressive strength is 3GPa, so maybe? Plus I assume one would surround everything with a "fluid" (or at least flows at that pressure) to distribute the forces. Silicon chip fluid suspended inside carbide anvil with a steel clamping structure and tightening bolts should work. Interconnects are left as an exercise for the reader.

I have enough faith that this would work out that I'd put it in a sci-fi story, and not enough that I would invest in a startup.

How close to a bomb would a device like this be? Feels like very close.

Or maybe more importantly, how much of my desk would be left after it went off?

Thin 1 mm2 speck of high explosive is like few milligrams - estimating from youtube vids that's not much. Might punch tiny hole into the underlying PCB at worst.

This is about 10,000x standard pressure. CRTs operate at 0.0000001x standard pressure, for reference -- they implode.

For example if superconductivity is desired from a 1 square inch (6.5e-4 m^2) footprint of this material, a weight of 6.5e5 N must fully rest on that footprint. Near the surface of earth that translates to a mass of approximately 146,000 lbs. Something like the mass of 3 tanks.

A cup of water operates at 10,000,000x the pressure of the crt tube and doesn't explode.

Pressure is a differential phenomena.

You'll have to ask a smart guy what deposition, subtraction, injection, or teleportation process he's going to use to make a permanent diamond container that leverages the high compressive strength because I'm stupid.

I wonder if it's possible to come up with a crystal or other material that has that much internal pressure - and isn't prone to unscheduled pressure release

First you have to make it easier to conduct experiment on before you can get more understanding.

If 1GPa is all that is needed, then yes this is a big breakthrough that can lead to wider research and more understanding.

Yeah, why is 1GPa being referred to as "near-room pressure"?

After a bit of googling, the yield strength of some common materials is within striking distance of 1GPa (many steels are 0.25 GPa, silicon carbide is 3.4 GPa [1]). So perhaps it could be possible to embed this superconductor in a highly stressed supporting structure to provide the pressure.

Not useful for cabling, but this could conceivably be used for room temperature SQUIDs [2], paving the way to cheap MRIs.

[1] https://www.engineeringtoolbox.com/young-modulus-d_417.html [2] https://en.wikipedia.org/wiki/SQUID

Wolfram Alpha tells me that to bring 10 sq. cm of the material to 1GPa would require 18x the bite force of a T-Rex. I don't consider the inside of a dinosaur's mouth "room pressure" either, but I could imagine a reasonably-sized housing capable of producing that force.

Another comparison for scale: It is 1/6th the pressure at which artificial diamonds are manufactured.

T-Rex bite strength sounds like something Abe Simpson would say. 16% of diamond pressure is a lot.

But diamond pressure is something that we are already capable of on a regular basis.

This would put it into the realm of engineering problems at least for some applications if this claim turns out to be true.

> Yeah, why is 1GPa being referred to as "near-room pressure"?

Because it's _very_ close to room pressure compared to other results. For example this team's last result (that's ... very questionable, but ignoring that), needed around 250 GPa.

Maybe a problem keeping it in a pressure vessel, but it might be possible to produce such high pressures at very small scales in solid state devices without use of a pressure vessel. In that case it would be more about changing the shape or bond angle of some nearby material to distort the electric field and induce the desired pressure.

AFAIK they don't use pressure vessels for pressures this high; they use diamond anvils.

1 GPa is less than half the yield strength of the best steels. All you would need to maintain the superconducting state is to put the material in a steel pipe.

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