from Hacker News

Ultrafast laser pulses produce a previously unseen phase of matter

by nerdy on 11/12/19, 11:20 AM with 33 comments

by cosmic_quanta on 11/12/19, 1:48 PM
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.
by gjm11 on 11/12/19, 11:59 AM
Original MIT press release of which this is a word-for-word copy: https://news.mit.edu/2019/light-orders-exotic-material-1111
Actual letter in Nature Physics: https://www.nature.com/articles/s41567-019-0705-3
by coldcode on 11/12/19, 1:08 PM
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
by cxcorp on 11/12/19, 1:24 PM
> 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.
by peter_d_sherman on 11/13/19, 5:01 AM
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!
by classified on 11/12/19, 2:25 PM
Exciting. Could we build a laser-pulsed Charge Wave computer?
by hinkley on 11/12/19, 10:40 PM
Is this going to end up having applications for integrated circuit manufacturing?
by gaze on 11/12/19, 2:32 PM
Holy shit, Pablo is on fire!
by jblakey on 11/12/19, 7:07 PM
Laugh-a while you can, monkey-boy.
by redog on 11/12/19, 2:21 PM
> "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?