New laser technique images quantum world in a trillionth of a second

Hi ATS!

There have been several threads on superconductivity (including mine), but there was/is unanswered questions about how it arises within high temperature super conductors (HTSC). Well, there is news on a couple fronts within the last 2 weeks.

First, a quick review. Electricity in a metal, is electrons jostling around into each other but instead of flying off in any direction they line up and move along. The problem is that all that motion and movement cause the energy the electrons are carrying to heat up the metal due to natural resistance within the metal itself (copper, aluminum. gold, etc). Enter quantum physics which predicted that below the Curie temperature, Tc, resistance would cease placing the metal in a superconducting state.

Most conventional superconductors require very low temperatures around absolute zero or -273 C.

In 1986, two relatively unknown physicists, working in a laboratory on a Swiss hilltop, made a discovery that started a revolution.

“It was the Woodstock of condensed matter physics,” said Enrico Rossi, associate professor of physics at William & Mary. “People were so excited. It changed everything.”

Physicists J. Georg Bednorz and K. Alex Mueller discovered superconductivity in ceramic material, specifically lanthanum-based cuprate perovskite, and created the first high-temperature superconductor.

The discovery earned them the 1987 Nobel Prize in Physics and held the promise that one day it could be feasible to transmit electricity and information over vast distances with virtually no loss of current or data.

William & Mary, news (wm.edu) - On the quantum dance floor, the 'twist' is king.

A few years ago, I authored a thread where lasers were used to probe where in the lattice structure it was possible to have SC states: Prerequisite for Room Temperature Superconductor Found.

There is a bunch of material concerning SC on that thread including HTSC rising and creating a basic scholastic feud between two competing theories.

And here is where we pick up the news (and source of the quote above),

Scientists have long debated the key ingredient that enables the cuprates to become superconducting at high temperatures: Does superconductivity emerge when electrons bind together in pairs, known as Cooper pairs, or when those pairs establish macroscopic phase coherence?

HTSC are a strange beast. They are similar to a "confused metal" (aka, "strange metal"), in that they look like they would never conduct at all and for all intents and purposes are actually an insulator.

So these researchers at the University of British Columbia (Canada) made, bought, constructed, or otherwise created a ridiculous laser that shoots femptosecond pulses (one quadrillionth of a second). They did some research on other topics and decided to that they could probably view materials in a new manner than what they were doing...

Leveraging the pulsed laser sources and facilities at SBQMI’s new UBC-Moore Centre for Ultrafast Quantum Matter, researchers established a new investigative technique to “watch” what happens to the material’s electrons during those ultrafast timescales.

Using this new technique they probed a HTSC cuprate.

Researchers at UBC’s Stewart Blusson Quantum Matter Institute (SBQMI) used a state-of-the-art, ultrafast laser funded by the Gordon and Betty Moore Foundation to answer the question.

The research indicates that the presence of an attractive “glue”, binding electrons into pairs, is necessary but not sufficient to stabilize the superconducting state. Rather, the Cooper pairs must behave coherently as a whole to establish a line of communication, with a single macroscopic quantum phase.

Univ. of BC - UBC researchers track the ultrafast emergence of superconductivity.

-and-

Phys.org, Dec. 10, 2019 - New laser technique images quantum world in a trillionth of a second.

The answer is "phase coherence"! All those Cooper pairs of electrons must all "row in the same direction" and be "in phase" for the SC canoe to move in the same direction.

But I think of the "how it was done" and marvel that we can "see" shadows of electrons and infer when they transition over from scattered to coherent (the actual study was the other way around, looking at when the HTSC state collapses but it shows the same thing). All in "a trillionth of a second"!!

Why it matters. (So when you see headlines like these you have an idea on how it works):
physicsworld.com - Superconductivity at the boiling temperature of water is possible, say physicists.
phys.org - Navy files for patent on room-temperature superconductor.

In the first article, you will realize that they are making an analog of metallic hydrogen so the material is under pressure (some ungodly amount that is impractical to put into boiling water!). And the second one... GAH! that one still ticks me off! First, it is using lead, so there is no way you can string up power lines of the stuff without it leeching out into the environment and killing everything! Second, there are no details but with this "phase coherence" and their "piezo driven" RTSC they begin to sound tantalizing similar.

I said it before about the quantum world, when you get a trillion trillion anythings all doing the same thing (i.e., coherence) you can get macro-world work done. And who knows where it ends?

At least now we can "see" it!



PS - Frikken' lasers! (lol)

In condensed matter physics, a Cooper pair or BCS pair is a pair of electrons (or different fermions) bound together at low temperatures in a specific way originally depicted in 1956 by American physicist Leon Cooper. Cooper showed that an arbitrary small attraction between electrons in a metal can cause a paired state of electrons to have a lower energy than the Fermi energy, which implies that the pair is bound.

As proposed in BCS theory, the Cooper pair state is responsible for superconductivity. Scientists even won Nobel Prize in 1972 for their work.

Resistance is created when electrons rattle around in the atomic lattice of a material as they move. But when electrons join together to become Cooper pairs, they undergo a remarkable transformation.

Electrons acts as fermions. Cooper pairs, however, act like bosons, which can happily share the same state. That bosonic behavior allows Cooper pairs to coordinate their movements with other sets of Cooper pairs in a way the reduces resistance to zero.

Scientists noted, “The idea that boson-like Cooper pairs are responsible for this metallic state is something of a surprise. because there are elements of quantum theory that suggest this shouldn’t be possible. So, understanding just what is happening in this state could lead to some exciting new physics, but more research will be required.”

Valles said, “The thing about the bosons is that they tend to be in more of a wavelike state than electrons, so we talk about them having a phase and creating interference in much the same way light does. So there might be new modalities for moving charge around in devices by playing with interference between bosons.”

techexplorist.com, Nov. 2019 - Introducing a new state of matter: a Cooper pair metal.

A little theory, a little history, and presented in decent sequence, it is not all gibberish! I like their explanation of electrons becoming "boson-like" where wave descriptions, including phase, help to align the jello into something about to phase transition from hunk of copper ceramic (in this example) to a HTSC

Putting it all together, electrons when approaching Tc begin to pair up but are not marching in-step. The macro state phase aligns all the pairs causing cohesion and SC.

Seems that entanglement is not just some curiosity created in physics labs but a real world (i.e., macro) phenomenon but is elusive enough to not always show itself?

This is all so cool 🤯🤯🤯

Seriously, we are at the door concerning Energy breakthroughs.

S&F for a dose of science today, ugh politics can be so tiresome.

Something that could also contribute in the advancement of quantumcomputing -or any kind of computing for that matter- at roomtemperature.

Vanadium type that conducts electricity but not heat

a reply to: Arnie123

TY!

A slightly different "cool under pressure" than politics! It has been piecemeal of late but there are enough bit here to keep on the radar!



a reply to: 2Faced

Vanadium is a rather strange element. It might be used for hardening steal but the pentoxide version can store energy (redox flow battery). Then add in conducting energy w/o heat. Makes me wonder if they are creating a 2D version and what that might be like!

a reply to: TEOTWAWKIAIFF

There has been a strategic silence concerning graphite based technology for 60 or 70 years so why would we learn anything new now? Unless a technology can be redesigned so that its safe and can't be reverse engineered they don't usually talk about it in the MSM. We were lucky to get laser disc in the 1950's.

a reply to: Slichter

Have you seen the Graphene Mega Thread?? When I joined in 2016 there were stories at least twice a week. Well, those become once a month. Now it is about every threes months.

Yeah, that tech is being held back!!



I’ve gotten to the point where if I can’t hold it in my hand then am no longer posting about it.

Holding tech back from the masses is evil. We are literally dying here and they are worried about money...

So.... uh.... explain it like I'm 5. What does this mean for real world future tech?

a reply to: jtrenthacker

I am not the author but I may try to reflect if I got this right.
If I am wrong I hope the author will correct it and something new is learned


Atoms swing the hotter they get and so do their electrons. They jitter around in the structure of the material. And bounce together with other electrons inside, while moving through material when they are free and not bound to an atom. This is the electrical resistance, the force that is working against you sending electrons in a nice row through the material.

Now superconductivity at room temperature:
Like kids in kindergarten they are paired together in pairs when they move. Then they can move smooth through the material with very very very little resistance. To pair up, two electrons have to share similarities, two similarities in this case. One of it is describe it as being in phase because there is a awkward thing happening where we can explain it as a wave or as a particle, similar to light.

Light can be described a photon or a wave.