
Ultrafast laser pulses produce a previously unseen phase of matter - nerdy
https://phys.org/news/2019-11-physics-ultrafast-laser-pulses-previously.html
======
cosmic_quanta
New phases of matter uncovered by ultrafast laser pumping is more common than
you might think.

Dumping a bunch of energy into a system in less than 30fs (30 x 10^-15s)
creates a profoundly non-equilibrium situation. Whatever phase of matter you
observe right after will likely have no equilibrium analogue.

> The perpendicular version of the CDW that appears after the burst of laser
> light has never before been observed in this material, Gedik says. It "just
> briefly flashes, and then it's gone," Kogar says, to be replaced by the
> original CDW pattern which immediately pops back into view.

The interesting bit is here:

> Gedik points out that "this is quite unusual. In most cases, when you add
> energy to a material, you reduce order."

That is what's great about this. New phases of matter in ultrafast experiments
are old news.

~~~
noobermin
It's upsetting. Reminds me of when the CERN people made that paper about
modulated plasma wave acceleration, and pretended they were the first to do
it, or at least the popular press did. You only realize it when it's your
field (as do I here) but we in physics ought to talk to each other more.

~~~
dredmorbius
An example I'd encountered was a set of papers out of the US Naval Research
Lab on fuel synthesis (electricity + seawater => hydrocarbon jet fuel). The
citations dated only to the mid/late 1990s, though it turns out prior art and
development date to at least the 1960s (for electically-based fuel synthesis),
the 1930s if Fischer-Tropsch synthesis from coal is included.

[https://old.reddit.com/r/dredmorbius/comments/22k71x/us_navy...](https://old.reddit.com/r/dredmorbius/comments/22k71x/us_navy_electricitytofuel_synthesis_papers_and/)

The impression generated was tremendously misleading.

I ended up digging into the history myself:

[https://old.reddit.com/r/dredmorbius/comments/29ihl7/us_doe_...](https://old.reddit.com/r/dredmorbius/comments/29ihl7/us_doe_synthetic_fuel_history_coaltoliquids_and/)

[https://old.reddit.com/r/dredmorbius/comments/28nqoz/electri...](https://old.reddit.com/r/dredmorbius/comments/28nqoz/electrical_fuel_synthesis_from_seawater_older/)

------
gjm11
Original MIT press release of which this is a word-for-word copy:
[https://news.mit.edu/2019/light-orders-exotic-
material-1111](https://news.mit.edu/2019/light-orders-exotic-material-1111)

Actual letter in _Nature Physics_ :
[https://www.nature.com/articles/s41567-019-0705-3](https://www.nature.com/articles/s41567-019-0705-3)

~~~
Intermernet
Sci-Hub link to pdf [http://sci-
hub.tw/https://www.nature.com/articles/s41567-019...](http://sci-
hub.tw/https://www.nature.com/articles/s41567-019-0705-3)

~~~
dmix
I'm not from academia but is it unusual to have 21 authors on a paper?

~~~
xaedes
My observations: I rarely see it in computer science related papers. I often
see it in biology / medicine papers (but I don't see lots of those papers)

If you wonder what 21 people do for one paper, they have mentioned it in the
paper pdf (look for the scihub link here in the comments) on the last page:
Only two people actually __wrote __the paper with input from a lot of others,
supervised by yet another one.

~~~
motajaxxer
Lab experiments involve huge amount of support people who have to do really
specific work for each experiment.

------
coldcode
Just when you think Physics has little left to discover, something you never
expected creates a whole new avenue to explore.

"When I began my physical studies [in Munich in 1874] and sought advice from
my venerable teacher Philipp von Jolly...he portrayed to me physics as a
highly developed, almost fully matured science" \- Max Planck

~~~
jermaustin1
I don't think physics will ever be fully matured. There is always a "Why?"
that needs an answer.

~~~
hawkice
I'm not sure that "Why?" is always going to be a physics question, but
certainly even after we understand the smallest building blocks, we will need
specific models of arbitrarily complex systems where the basic rules are
computationally infeasible or resistant to simple analysis.

Of course, understanding the true and most basic workings of nature will also
take a lot of work, just not a literally infinite supply.

~~~
eru
Thanks to chaos, we will probably have no shortage of computationally
infeasible systems.

Though the study of those systems is often labelled by something other than
'physics'. Biology or Chemistry or Psychology or Economics etc.

------
cxcorp
> The idea that two possible states of matter might be in competition and that
> the dominant mode is suppressing one or more alternative modes is fairly
> common in quantum materials, the researchers say. This suggests that there
> may be latent states lurking unseen in many kinds of matter that could be
> unveiled if a way can be found to suppress the dominant state.

How exciting! I can only daydream about the kind of discoveries to be found
about matter in, say, 50 years.

~~~
throw1234651234
I don't understand it enough to get excited - what are the potential
applications?

~~~
AngryData
I don't think anyone can predict the applications because creating new
materials could have many, or almost no, novel or useful properties. Look at
how many different ways we can manipulate iron and create different
properties, now there might be even more. Or maybe it isn't stable in bulk
atmospheric amounts, but can be held under pressure and has some unique
property to make it suitable for computing, or detecting certain kinds of
energy or radiation, or forms piezoelectric properties or who knows. Maybe it
can be used in optical data processing or amplifying.

Most likely this isn't going to revolutionize our world, but there is always
that small chance, and we will certainly find some use for these novel states
of matter somewhere, if not just more physics experiments.

------
peter_d_sherman
Excerpt:

"In this material, a wavelike pattern of electrons in high- and low-density
regions forms spontaneously but is confined to a single direction within the
material. But when hit with an ultrafast burst of laser light—less than a
picosecond long, or under one trillionth of a second—that pattern, called a
charge density wave or CDW, is obliterated, and a new CDW, _at right angles to
the original_ , pops into existence.

This new, perpendicular CDW is something that has never been observed before
in this material. It exists for only a flash, disappearing within a few more
picoseconds. As it disappears, the original one comes back into view,
suggesting that its presence had been somehow suppressed by the new one."

My thoughts:

The first thought that comes to mind is "superposition"... The second thought
that comes to mind is "possible higher-dimensional and/or phase-shifted view
of the substructure of matter" (in this case, lanthanum tritelluride)... Even
if neither of these things turn out to be the case, the phenomena is
fascinating!

------
classified
Exciting. Could we build a laser-pulsed Charge Wave computer?

------
hinkley
Is this going to end up having applications for integrated circuit
manufacturing?

------
gaze
Holy shit, Pablo is on fire!

------
jblakey
Laugh-a while you can, monkey-boy.

------
redog
> "What if all you need to do is shine light on a material, and this new state
> comes into being?"

Wonder if it's related to photosynthesis?

~~~
semi-extrinsic
It's not. Photosynthesis is a chemical reaction where light provides energy
and that only involves gas, liquid and solid states of matter.

These guys are talking about entirely different states of matter.

~~~
codeulike
I seem to remember there were some mysteries around how photosynthesis works.
Although looking at wikipedia it seems quite comprehensively mapped out now

