Twisting Stacked Graphene Reveals Potentially Powerful Superconducting Behavior | Hacker News Reader

Twisting Stacked Graphene Reveals Potentially Powerful Superconducting Behavior

gizmodo.com

46 points_Microft21 comments

Physicist joke: there is only one thing that graphene is unable to do : getting out of the lab.

Its interesting that graphene does have superconducting behavior, but its still does not occur until very low temperature[0]. This is a brand new discovery, so it will be exciting to see how it advances. There are more degrees of freedom to be explored: doping, twist angle, multiple layers, etc.

[0] "The graphene sheets still required temperatures around 1.7 degrees above absolute zero, -456.6 F, to demonstrate superconductivity."

Does anyone know how difficult/expensive it is to get something that cold?

It seems like it would be virtually infeasible, but I really have no idea.

It doesn't directly answer your question, but you might find this interesting: http://omegataupodcast.net/285-superconductivity/

It's below the condensation temperature of helium, so they probably cool it by evaporating liquid helium. Sample volume, existing kit, helium recycling loops are going to vastly change the price structure of that experiment.

In terms of costs your thresholds are the boiling points of nitrogen (77K, surprisingly cheap and easy to deal with, even for a hobbyist) and helium (33K, more expensive,scarce, requires more energy to condense). To get lower than that, you need your own cryogenic cascade as I doubt you can easily buy something as ridiculously dangerous as liquid hydrogen (boiling point of 4K, explosive in contact with oxygen).

At less than 2K I think that the only merits of this discovery are theoretical.

I don't think that anyone believes that superconductors below nitrogen temperature have any viability outside the lab.

You mixed up the temperatures for hydrogen and helium.

Thanks!

liquid hydrogen safety https://www.youtube.com/watch?v=7bFJK5kU_UQ

[it doesn't explode on contact with air]

I find the newly observed properties to be interesting and hope that they lead to a deeper understanding of superconductivity in general.

Has there been any commercial use case for graphene yet?

I feel as though I've been hearing about its potential constantly for many years, but can't recall any commercial use cases yet.

(side note - it also reminds me of the many hours I spent using the scotch tape method and looking at my chip under microscope to try and identify graphene...)

Apparently it’s already being used for supercapacitors: https://newatlas.com/adgero-ultracapacitor-trailer-kers/4299...

Bicycle tyres

Graphene can be used to detect molecules in the air which has applications in air pollution monitoring. https://phys.org/news/2016-04-graphene-based-sensor-air-poll...

I think I'm approaching my 10th year anniversary of hearing the wonderful things graphene can do.

Curiously, it might also be the 10th year anniversary of hearing that the graphene revolution is "just around the corner"

That's a long corner to turn

I'll see your graphene and raise you a fusion.

At least there's progress being made there:

https://en.wikipedia.org/wiki/ITER

Who would have thought the Moiré interference pattern could have a large physical effect? The hexagons generated from the twist shown at the top image form clearly visible long paths.

To recycle some musings from a similar article a few months ago:

> Layperson question] Looking at that moire pattern shown in the 1.1-degree rotated sheets, I find myself wondering about quantum-tunneling. No good reason, just the visual appearance of relative "voids" when the sheets are in-sync.

> Is there any known (or theorized) relationship between superconductors and tunneling? Does the "pattern repeat distance" of those 1.1-degree-twisted sheets come close to some important threshold that relates to electron-tunneling?

https://www.reddit.com/r/science/comments/82avjf/comment/dv9...

How far are we from graphene economy ?

Time to economically viable fusion, multiplied by two.

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