
Superconductivity near room temperature - Elof
https://www.nature.com/articles/d41586-019-01583-y
======
PuffinBlue
The interesting thing about this is that the work neatly fitted with existing
theory:

> Drozdov et al. observed this isotope effect and found that, compared with
> the lanthanum hydride samples, the critical temperature in lanthanum
> deuteride samples is lower by almost exactly the amount predicted by the
> theory.

So like the article points out:

> From a scientific standpoint, these results suggest that we might be
> entering a transition from discovering superconductors by empirical rules,
> intuition or luck to being guided by concrete theoretical predictions.

Whilst this result might require huge pressures, steady progress towards a
theory of super-conduction is an exciting thing indeed.

~~~
djaque
I wouldn't be too optimistic. The theory they are talking about is BCS theory.
Most of the other high TC superconductors cannot be explained with it and high
TC BCS superconductivity so far requires crazy environments with no clear path
to making them easier to use. With the kinds of pressures required to make
this happen, it's probably easier to just buy liquid nitrogen and use other
materials.

------
ttsda
At pressures a million times those experienced on earth. Still an advance, of
course.

~~~
Zanni
Nobody wants "high temperature" superconductors. They want superconductors at
roughly standard temperature and pressure. This is only an advance by the
extremely artificial metric of considering temperature only. Ceramic
superconductors work at liquid nitrogen temperatures and standard pressure,
which is much more accessible.

I'm not raging at ttsda. It _is_ an advance. Of sorts. But not nearly as much
as the headline suggests.

~~~
gaze
You’re vastly underestimating what the significance of what this is part of.
High Tc superconductivity was thought to be essentially dead. Extremely few
significant new results for decades. Now this and magic angle twisted graphene
and some other stuff. It’s really really cool. It’s like we’re watching an
entire field thawing and lurching forward.

~~~
galangalalgol
Is the graphene thing dead? One paper indicated graphene or even graphite
soaked in a hydrocarbon would superconduct at room temperature. I was so
excited I purhased some and tried that, it had a DC impedance similar to dry
graphite...

~~~
TeMPOraL
Did you buy graphene or graphite? If the former, maybe what you got wasn't
actually graphene? Apperently, the progress in this field is held back by most
suppliers selling something they claim that's graphene but really isn't (or is
of garbage quality) -
[https://blogs.sciencemag.org/pipeline/archives/2018/10/11/gr...](https://blogs.sciencemag.org/pipeline/archives/2018/10/11/graphene-
you-dont-get-what-you-pay-for).

------
bhaak
> From a scientific standpoint, these results suggest that we might be
> entering a transition from discovering superconductors by empirical rules,
> intuition or luck to being guided by concrete theoretical predictions.

That would be an exciting development.

------
acd
Is the Sun a superconductor? The Sun consist of a high percentage of hydrogen
~73% and there must be really high pressure at the center.

The suns central pressure is 2.5*10^11 bar according to nasa.

[https://en.m.wikipedia.org/wiki/Sun](https://en.m.wikipedia.org/wiki/Sun)

[https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html](https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html)

~~~
skykooler
The sun is also at a temperature of millions of degrees. At these
temperatures, there is no such thing as chemical bonds, and so the rules with
hydrogen from the article don't apply.

~~~
agumonkey
interesting, is this a sub-field of physics ? high temperature physics or
something ?

~~~
orbifold
Plasma physics I guess, plus magneto hydrodynamics, plus GR for really heavy
stars.

~~~
agumonkey
dank u

------
yo1
Has this been discussed here? Navy files for patent on room-temperature
superconductor.

[https://phys.org/news/2019-02-navy-patent-room-
temperature-s...](https://phys.org/news/2019-02-navy-patent-room-temperature-
superconductor.html)

"The application claims that a room-temperature superconductor can be built
using a wire with an insulator core and an aluminum PZT (lead zirconate
titanate) coating deposited by vacuum evaporation with a thickness of the
London penetration depth and polarized after deposition.

An electromagnetic coil is circumferentially positioned around the coating
such that when the coil is activated with a pulsed current, a non-linear
vibration is induced, enabling room temperature superconductivity.

"This concept enables the transmission of electrical power without any losses
and exhibits optimal thermal management (no heat dissipation)," according to
the patent document, "which leads to the design and development of novel
energy generation and harvesting devices with enormous benefits to
civilization.""

------
gwbas1c
> lanthanum hydride compounds become superconducting at 250 K

That's about -10F, or -23C.

(And it would make a lot more sense to put that in the article. Most of us
don't "think" in Kelvin.)

~~~
nine_k
It's easy: "room temperature" is about 300K.

------
apo
> Writing in Nature, Drozdov et al.1 report several key results that confirm
> that, when compressed to pressures of more than one million times Earth’s
> atmospheric pressure, lanthanum hydride compounds become superconducting at
> 250 K — a higher temperature than for any other known material.

 _One million atmospheres_ is an important detail to leave out of the title.

------
chiefalchemist
> "Materials known as superconductors transmit electrical energy with 100%
> efficiency."

What is the level of (in)efficieny for say power lines? And power cords, etc
around the office/house?

That is, of the electricity produced, how much is lost due to how it's
transported? Does decentralizing production (e.g., solar panels on your own
roof) help in any way?

~~~
skosch
The bit of heat produced in a power line isn't a huge deal. The more important
applications will be in electronics and electromagnets. For instance, it would
make nuclear fusion reactors cheaper and easier to build.

~~~
chiefalchemist
So this isn't about advancing scale and distribution, it's at the end product
and product sub-component level. Good to know.

~~~
jerf
It is also possible it will enable some setups that aren't currently possible.
Part of why transmission loss in power lines is as low as it is is that we
build plants near to where the electricity is going to be used, so it's not
some sort of physics law that the loss is that low, it's engineering. Right
now, the "plate the Sahara in solar to power Europe" solution is not
technically feasible due to the transmission loss across that distance.
Obviously that's a special case of the general problem of natural power
sources not being where people live. If we can transmit power without loss, we
get some more options than we have now.

I'd still guess the bulk of the value would be in more local uses, but there
are some interesting large-scale possibilities, including power transmission.

------
trebligdivad
What's the highest pressure that can be achieved over a useful (1 meter?)
distance? I find it amazing that they managed to scale up cryostats to 1km for
superconducting powercables at low temperatures - it would just be interesting
if they started scaling up high pressure environments.

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oh_teh_meows
I understand that the achievement in question was made in a high pressure
environment; but if we get room temperature superconductors (at standard atm
pressure), does that mean large scale hover cars/boards deployment will be
viable as well [0]?

[0] [https://youtu.be/PXHczjOg06w](https://youtu.be/PXHczjOg06w)

~~~
wolfram74
Room temperature super conductors are in the category of materials that will
cause semi-magical transformations in society along side generation techniques
that make .001$/KwH electricity, 1$/kwh electricity storage, or >200 gigaPa
tensile strength materials for cheap.

