
Surprise graphene discovery could unlock secrets of superconductivity - rbanffy
https://www.nature.com/articles/d41586-018-02773-w
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bergoid
Previous discussion:
[https://news.ycombinator.com/item?id=17743796](https://news.ycombinator.com/item?id=17743796)

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apo
_Superconductors come broadly in two types: conventional, in which the
activity can be explained by the mainstream theory of superconductivity, and
unconventional, where it can’t. The latest studies suggest that graphene’s
superconducting behaviour is unconventional — and has parallels with activity
seen in other unconventional superconductors called cuprates. These complex
copper oxides have been known to conduct electricity at up to 133 degrees
above absolute zero. And although physicists have focused on cuprates for
three decades in their search for room-temperature superconductors, the
underlying mechanism has baffled them._

Magic angle graphene (sheets twisted 1.1 degree relative to each other) isn't
a temperature breakthrough because the sample must be cooled to 1.7 K.

Rather, it appears to be a novel system for studying unconventional
superconductors. The best-studied example to date is based on cuprates. Both
cuprates and magic angle graphene are characterized by insulting state very
close to a superconductivity state.

The hope seems to be that magic angle graphene will prove to be a better
system for understanding unconventional superconductivity. That could lead to
high temperature superconductors.

 _In contrast to cuprates, the stacked graphene system is relatively simple
and the material is well-understood. “The stunning implication is that cuprate
superconductivity was something simple all along. It was just hard to
calculate properly,” says Laughlin._

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IIAOPSW
I'm going to take a wild guess that it has something to do with electron de
broglie wavelength somehow being resonant in certain lattice structures.
Twists in graphene layers are known to create a morie pattern giving it a
quasi-periodic structure at much higher length scales than simple atomic
lattices. This is likely related.

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lawlessone
>And although the system still needed to be cooled to 1.7 degrees above
absolute zero,

awww :(

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yonkshi
Correct me if I'm wrong, but I think the significance of this finding is not
so much about temperature, rather it's a big piece of the puzzle in
understanding superconductivity. This is the first time that we are able to
achieve superconductivity via mechanical property rather than molecular
property. Our current superconductors are based some crazy alloys, and we have
little insight of why they are superconductive.

In this finding they were able to make graphene superconductive by simply
shifting two sheets of graphene by 1.1 degree angle. Graphene consists of only
carbon atoms, its atomic properties are much easier to model than an alloy, so
by examining why this magical angle work, it can greatly help us understand
why superconductivity occur, eventually helping us design higher temperature
superconductors.

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Ensorceled
Correct. It's a significant finding. I'm annoyed at the breathless
explanations of our current superconductor situation as a lead in followed by
this revelation that this new superconductor isn't really useful as a high-
temperature superconductor at all.

I.e. I'm annoyed by the writing not unimpressed with the science :-)

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guilamu
Any article with the words "graphene breakthrough/discovery" or "battery
breakthrough/discovery" should get a blanket ban...

/s

I guess...

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hobbes78
It's interesting that every single article about graphene shows a 3D model of
a plane of molecules, but never a photo...

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vertline3
Science headlines with the word 'could', 'could' hold the secret of eternal
youth.

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Svoka
> Graphene can do just about anything except leave the lab.

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Graham24
This is six months old

