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Prerequisite for Room Temperature Superconductor Found

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posted on Apr, 16 2018 @ 02:04 PM
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What they found was odd - as the material warmed up from absolute zero, the amount that a magnetic field could penetrate the material increased linearly instead of exponentially, which is what is normally seen with superconductors.

After running a series of measurements and calculations, the researched concluded that the best explanation for what was going on was that the electrons must have been disguised as particles with higher spin - something that wasn't even considered as a possibility for a superconductor before.

While this new type of superconductivity still requires incredibly cold temperatures for now, the discovery gives the entire field a whole new direction.

"We used to be confined to pairing with spin one-half particles," says lead author Hyunsoo Kim.

"But if we start considering higher spin, then the landscape of this superconducting research expands and just gets more interesting."

This is incredibly early days, and there's still a lot we have to learn about exactly what's going on here.

But the fact that we have a brand new type of superconductivity to test and measure, adding a cool new breakthrough to the 100 years of this type of research, is pretty exciting.

sciencealert.com - Physicists Just Discovered an Entirely New Type of Superconductivity.

Full disclosure: This was not found at some high temperature and it was also under pressure.

The OP explains Cooper pairs. Those are pairs of electrons with 1/2 spin. This announcement is about finding superconductivity in 3/2 spin electrons. Everybody expected it to be there but in something like a gas for not a solid material. This discovery abuts against the next news item.

 



By applying an algorithm to a strange section of the periodic table of elements, physicists have at last been able to predict which elements could pair up with hydrogen to create a room temperature superconductor - one of the "holy grails" of physics.


Now, researchers from the Moscow Institute of Physics and Technology and Skoltech, Russia, have devised a process to pick out which of a special type of metals, known as actinides, in the periodic table would be stable enough under certain conditions to exhibit superconductivity.

And it's already led to the discovery of a material that could become a superconductor at a relatively toasty minus 20°C (minus 4°F) - although it still needs to be squeezed under high pressure.

The actinides are a series of 15 metals with large atomic numbers 89 to 103 (actinium to lawrencium), sitting alongside that other weird 'outside' block of elements, the lanthanides.

Observations of the way various metal hydrides conduct electricity at certain temperatures had led researchers to suspect there was a pattern reflected by their positions in the periodic table, but the exact link wasn't clear.


This new algorithm used the arrangements of the electrons in the actinide series of elements to predict which could team with hydrogen to provide an ideal lattice, one that would result in a strong electron-phonon interaction.

The result is the discovery of superconducting actinium hydrides that could be as warm as minus 20°C (minus 4°F).

They still need 1.5 million atmospheres of pressure, but having a better handle on how to pick and match elements to create 'warm' superconducting materials is a find worth paying attention to.

While there are still plenty of hurdles to overcome before we can expect to have resistance-free technology in our home, discovering a general principle linking the phenomenon with the periodic arrangement of elements is a significant step forward.


And it's already led to the discovery of a material that could become a superconductor at a relatively toasty minus 20°C (minus 4°F) - although it still needs to be squeezed under high pressure.

sciencealert.com, April 12, 2018 - A Pattern Hidden in The Periodic Table Could Lead to The Holy Grail of Superconductors.

Most of the research is centered around cuprates (i.e., containing copper) that are ceramic in nature. Looking at other atoms was not very interesting because a lot of materials are super conducting.

This is like finding a spice market when you only had salt and sugar!

Add the two stories together... you can kind of see what should happen next: a new recipe at normal atmospheric pressure and at dry ice temperatures!




posted on May, 24 2018 @ 02:48 PM
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This is going to take some explaining.

SC - Super Conductor. A material that looses all resistance allowing electricity to flow through.

HTSC - High Temperature Super Conductor. Instead of being close to absolute zero these materials become SC at warmer temperatures.

Critical Temperature - Transition point in a material when it becomes a SC.

BEC - Bose-Einstein Condensate. A material made by lowering the temperature so all the molecules making up the BEC behave as one atom sharing the same quantum state. Good example is liquid helium that climbs out of its container. That is a jar of helium gas super cooled down to a BEC.

Cooper Pairs - Electrons that pair up and thought to be the cause of super conductivity. AKA, BCS Pair.

BCS Theory of SC - Named after John Bardeen, Leon Cooper, and John Robert Schrieffer, who theorized that interaction of electrons in the crystal lattice structure of SC materials create Cooper Pairs.

Polaron - A "quasi-particle" used to describe electron interaction in the crystal lattice SC. The crystal lattice deforms but does not break and electrons travel through the lattice in waves.

Bipolaron - A pair of polarons bound by a phonon.

Armed with a few terms what follows should make some sense. This researcher was measuring various aspects of BEC. This is theoretical (the calculations were done with an idealized BEC) but what it explains is what BCS Theory cannot. And that is what is important (not all the geeky terms which are my own explanations to myself, they are just "high-level" and not scientific, spot-on, writing a paper bound for the arxiv level). To the news...


Victor Lakhno, head of the Laboratory of Quantum-Mechanical Systems of the Institute of Mathematical Problems of Biology, RAS -- the Branch of Keldysh Institute of Applied Mathematics RAS has calculated a critical temperature of the transition, energy, heat capacity and heat of transition of an ideal three-dimensional Bose-condensate of translation-invariant bipolarons (TI-bipolarons). The results obtained offer an explanation of the experiments with high-temperature superconductors.
...

In his calculations he proceeded from the same factors as the classical BCS theory did. However He excluded the electron variables from the Froehlich Hamiltonian of electron-phonon interaction instead of the phonon ones. Since in the case of a linear dispersion law (as in the BCS) phonons represent quantized acoustic waves, it can be said that in the TI-bipolaron theory, SC is caused by charged acoustic waves which form a SC condensate. In the case of HTSC materials, according to his theory, we deal not with acoustic phonons, but with optic ones since these materials are ionic crystals. As a result, the theory describes a charged Bose gas of optical phonons coupled with electron pairs which are translation-invariant (TI) bipolarons. Like Cooper pairs TI-bipolarons are plane waves possesing a small correlation length equal to several constants of the crystal lattice.

The qualitative difference of this theory from the other ones is that it implies that even at zero temperature only a small portion of all the electrons are in the TI-bipolaron (paired) state. This corresponds to the results obtained in Bo�ovi? [sic] et al experiments in 2016 and opens up new opportunities for creation of room-temperature superconductors. Since this theory suggests that in order to enhance the critical temperature of the transition, one should enhance the concentration of TI-bipolarons.

Eurekalert.org, May 24, 2018 - Theory gives free rein to superconductivity at room temperature.

What has been found is an explanation of one material (BEC) that gives rise to similar properties in another material (HTSC) and a method of inducing that property (i.e., Cooper pairs), even at room temperature!



posted on May, 24 2018 @ 02:54 PM
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To produce a superconducting cable operable at room temperature one should use strongly underdoped HTSC material (whose SC transition temperature is very low, i.e. a few K). This material, however, already contains bipolarons, though in very small quantity. It only remains to enhance their concentration without resort to doping. This can be arranged by making the cable coaxial so that the internal small-diameter cable isolated from the external one could induce a strong electric field attracting bipolarons.

Victor Lakhno (same source)


There you go ATS! A room temperature superconducting cable for lossless energy transmission.

I said to get nuclear fusion up and going we first need energy storage and efficient energy transmission. Vanadium redox flow batteries have had the national regulations clarified (USA) so that is about to happen nationwide. A theoretical loss-less Room Temperature SC seals the deal.

Can we get on with our nuclear fusion future??



posted on May, 24 2018 @ 03:18 PM
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For comparison, room temperature in Kelvin is 293 - 298.

BCS Theory stated SC could not go above 30 K. When HTSC were discovered that proved to not be true (160 K). Hydrogen sulfide has been demonstrated as SC at 203 K but under high pressure.

Fun read at singularityhub.com - Why the Discovery of Room-Temperature Superconductors Would Unleash Amazing Technologies.

FYI, Wikipedia: Coaxial Cable.




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