Superconductor 'flaws' could be key to its abilities

Aug 23, 2012
Superconductor 'flaws' could be key to its abilities
Purdue physicist Erica Carlson stands in front of an illustration of the fractal clusters present in copper-oxygen based superconducting material. Photo: Mark Simons

(Phys.org)—Many researchers studying superconductivity strive to create a clean, pure, perfect sample, but a team of physicists found that some flaws might hold the key to a material's unique abilities.

Erica Carlson, a Purdue University associate professor of physics, led a team that mapped seemingly random, four-atom-wide dark lines of seen on the surface of copper-oxygen based superconducting . The team uncovered a pattern in these flawed lines, which are separate from the expected structure of the material, and discovered that they exist throughout the crystal. The findings suggest the lines could play a role in the material's at much higher temperatures than others.

"This material is ceramic, like your dinner plates, and it has no business conducting electricity, but under the right conditions it conducts electricity perfectly with zero ," Carlson said. "A better understanding of how and why this superconductor works could help us design better ones. If we can create a superconductor that works at high enough temperatures, it could transform how we use and generate energy."

For instance, superconductive wires could lead to power lines that do not leak electricity in transit, saving tremendous amounts of energy and money. Superconductors also have special that could allow for levitated, frictionless trains and stronger, more durable permanent magnets like those used in , she said.

The electrons confined to these mysterious lines behave radically different than those that freely move throughout the crystal, and it had been suggested that they could play a role in superconductivity. However, whether the lines were merely or extended into the material was unknown because the that reveals them can only be used on the material's surface, she said.

Carlson collaborated with Karin Dahmen from the University of Illinois and Purdue graduate student Benjamin Phillabaum on a study to examine the tiny, ladderlike lines that point vertically or horizontally across the surface of the crystal. By treating sets of neighboring parallel lines as part of a single "cluster," the team discovered that the patterns formed by the clusters are fractal in nature, meaning they fall between two dimensions of space, Carlson said.

"When thinking of a fractal, imagine a crumpled piece of paper," she said. "It is more than the two-dimensional flat piece of paper and it enters three dimensions, but it does not quite fill that space. It is not a true and solid ball. Fractals can occupy fractions of a dimension. They also have a pattern that is maintained even as you view smaller and smaller pieces of it."

Fractal patterns are mathematically understood, and the patterns present on the surface of the copper-oxygen based high-temperature superconductors could be compared to known models of how that pattern can arise. Using this information, the team was able to determine that these patterns originate from deep inside the material. A paper detailing the NSF and Research Corporation for Science Advancement-funded research was published in Nature Communications.

The fractal patterns also offer information about the space they occupy, and through this work the team developed a new analysis method to help understand the materials and the interactions going on inside of them, Carlson said.

"If you see pattern formation, then you can try to identify the fundamental physics causing its formation," she said. "It can apply to a lot of systems and materials beyond ."

Carlson said the method could be used to identify the dominant class of disorder present in a material, which helps in understanding its unique characteristics.

"We want to move beyond trying to get rid of disorder, striving for unattainable purity in the materials we examine, and instead take the disorder into account and use it to our advantage," Carlson said. "These little patches of imperfection where things aren't lined up in a perfect crystal lattice are important, and old methods that overlooked them fail to capture important physics. The flaws in the lines are like a fingerprint. They reveal the identity deeper inside."

Explore further: Physicists unlock nature of high-temperature superconductivity

More information: Spatial Complexity Due to Bulk Electronic Nematicity in a Superconducting Underdoped Cuprate, B. Phillabaum, E.W. Carlson and K.A. Dahmen, Nature Communications, 2012.

Abstract
Surface probes such as scanning tunneling microscopy have detected complex electronic patterns at the nanoscale in many high-temperature superconductors. In cuprates, the pattern formation is associated with the pseudogap phase, a precursor to the high-temperature superconducting state. Rotational symmetry breaking of the host crystal in the form of electronic nematicity has recently been proposed as a unifying theme of the pseudogap phase. However, the fundamental physics governing the nanoscale pattern formation has not yet been identified. Here we introduce a new set of methods for analyzing strongly correlated electronic systems, including the effects of both disorder and broken symmetry. We use universal cluster properties extracted from scanning tunneling microscopy studies of cuprate superconductors to identify the fundamental physics controlling the complex pattern formation. Because of a delicate balance between disorder, interactions and material anisotropy, we find that the electron nematic is fractal in nature, and that it extends throughout the bulk of the material.

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daywalk3r
3.9 / 5 (11) Aug 23, 2012
The team uncovered a pattern in these flawed lines, which are separate from the expected structure of the material, and discovered that they exist throughout the crystal. The findings suggest the lines could play a role in the material's superconductivity at much higher temperatures than others.
Those are "electron channels" which represent the major principle behind the superconductive properties of many of todays known types of superconductors.

Electrons move through these channels without being re-captured by electron "holes", so there is no energy loss associated with that process (where part of the energy of the electron is transfered to kinetic energy of the nucleus, eg. to heat).

The electrons are confined/compressed to these "channels" by speciffic topological features of the materials atomic/molecular structure. "Copper pairs" anyone?

The principle is really simple. I know about it for more than 10 years at least.. I thought it is quite obvious? :-S
daywalk3r
3.9 / 5 (11) Aug 23, 2012
And one more thing to add:
The team uncovered a pattern in these flawed lines

"Flawed" is not really the right word to use. The lines might not be perfectly straight, but the point is that they are "straight enough" to not cause the electrons to fall off the edge when racing through.

At higher temperatures these "lines" become more distorted (or even discontinuous) and this is pretty much what defines the Tc of a superconductor.

Some configurations result in stronger channels which directly translates to a higher superconductivity onset temperature (Tc). The distance between the channel junction points probably also plays an important role as it relates to the substance of the channels weakest points.
johanfprins
1 / 5 (1) Aug 24, 2012
They have observed Mott orbitals. In the ceramics the Mott-orbitals form BETWEEN the crystallographic layers (CL's): That is why one can also observe them ON the surface of the ceramic. When these orbitals reach a critical density, SC occurs by means of quantum fluctuations (QF). No acceleration is required; no increase in kinetic energy; and thus no force acting on the charge-carriers: No force means no gradient in potential energy: ergo SC.

You can also have Mott-orbitals WITHIN the CL.s. The so-called "gaps" that form within the phase diagram are NOT gaps at all, but a change in the conduction mechanism. Conduction can also occur WITHIN the CL's by thermal hopping (TH). When this conduction is replaced by TH BETWEEN the layers the so-called pseudogap is measured. When the latter conduction is replaced by quantum hopping SC initiates.

Congratulations: The mainstream bigots are slowly discovering what I have tried to publish during the past 10 years. Maybe another 100 years?
johanfprins
1 / 5 (1) Aug 24, 2012
Natello, Natello, Natello! Please think like a scientist!!!! Please first explain how a current flows though a superconductor (even when the charge-carriers do not scatter) if the charge-carriers can be accelerated. If they accelerate, work is done on them: A force acts, so that there MUST be a change in electric-potential along the direction in which the charge-carriers are flowing (ever heard of force=grad(potential)?): Ergo: When charge-carriers can accelerate SUPERCONDUCTION IS IMPOSSIBLE!
Minich
not rated yet Aug 29, 2012
Ergo: When charge-carriers can accelerate SUPERCONDUCTION IS IMPOSSIBLE!
It is such a nonsense :)
You should better measure anything experimentally.
Theory is not your ocean.
Electron in any atom is forever accelerated, but in ground state the atom is stable!
In any superconductor there are accelerated atoms (phonons) with accelerated electrons. Touch and accelerate any superconductor, in most of the cases superconductor remains superconducting.

Minich
not rated yet Aug 29, 2012
We use universal cluster properties extracted from scanning tunneling microscopy studies of cuprate superconductors to identify the fundamental physics
It is very difficult to identify physics of HTSC (cuprates, pnictides,..).
I think it is more easily to guess! Without Cooper paring and WITH dispersion electron relations.
johanfprins
1 / 5 (1) Aug 30, 2012
You should better measure anything experimentally.
Theory is not your ocean.
It is YOU who cannot even understand kindergarten theoretical physics!!
Electron in any atom is forever accelerated, but in ground state the atom is stable!
Everybody knows that when an electron accelerates it MUST emit EM-radiation. It is an oxymoron statement to say that an electron in its ground-state accelerates.
In any superconductor there are accelerated atoms (phonons)
Not at T=0
Touch and accelerate any superconductor, in most of the cases superconductor remains superconducting.
A superconductor which ONLY has SC charge-carriers (CC's) is an insulator when there is no SC-current flowing! Phonons have NOTHING to do with causing SC. The isotope effect is measured because the SC charge-carriers are localised states within an insulator. You still have not answered how the CC's can accelerate when there is no voltage drop
johanfprins
1 / 5 (1) Aug 30, 2012
We use universal cluster properties extracted from scanning tunneling microscopy studies of cuprate superconductors to identify the fundamental physics
It is very difficult to identify physics of HTSC (cuprates, pnictides,..).
Difficult for you YES!! You know less about physics than my goldfish!

Localised MOTT orbitals will exactly act as these measurements are showng.
Minich
not rated yet Aug 30, 2012
Electron in any atom is forever accelerated, but in ground state the atom is stable!
Everybody knows that when an electron accelerates it MUST emit EM-radiation.
It must? This paradox of quantum mechanics exists almost 100 years. And nobody could explain it. Why does not electron in atom fall to nuclears?
Everybody knows Coulomb's law (inverse-square law)....

He he...
Minich
not rated yet Aug 30, 2012
Localised MOTT orbitals will exactly act as these measurements are showng.
I guess that you don't understand the word "orbital". Orbital and "Mott orbital" what is the difference in wave (quantum) mechanics? Can you calculate something for them?
He He
johanfprins
1 / 5 (1) Aug 30, 2012
Everybody knows that when an electron accelerates it MUST emit EM-radiation.
It must? This paradox of quantum mechanics exists almost 100 years. And nobody could explain it.
Wrong!!! I can explain it. And in fact Schroedinger explained it already in 1927: His equation gives STATIONARY WAVES AND STATIONARY WAVES HAVE NO MOMENTUM
Why does not electron in atom fall to nuclears?
Since a stionary wave does not move: therefore there is no acceleration and therefore no emission of radiation which requires that the electron-wave must end up in the nucleus.

Everybody knows Coulomb's law (inverse-square law)....
So?

johanfprins
1 / 5 (1) Aug 30, 2012
Localised MOTT orbitals will exactly act as these measurements are showng.
I guess that you don't understand the word "orbital".
No it is AGAIN YOU who do not understand physics.
Orbital and "Mott orbital" what is the difference in wave (quantum) mechanics?
Orbital came into existence owing to Bohr's physically impossible model of the atom which claims that an electron "orbits" the nucleus. It unfortunately stuck. At present "orbital" is used for a localised stationary matter-wave
u calculate something for them?
Yes I can and I have done this: This is why I can model superconduction within any material while YOU cannot!
He He

Minich
not rated yet Aug 30, 2012
I,I,I.....
I see...
I launch stationary electron with p=Velocity*mass and somebody claims that my stationary electron's matter wave " HAVE NO MOMENTUM"...
He he :)

Gilbert by the way introduced termin "transfer" something ALONG the curve, something can be mass or momentum or spin or charge or ... Can you give the definition of MOMENTUM?
Minich
not rated yet Aug 30, 2012
Wrong!!! I can explain it.
Of course,You can!!!By postulating and shaman guestures with a drum beating :)
Hehe
johanfprins
1 / 5 (1) Aug 31, 2012
I launch stationary electron with p=Velocity*mass
How and where did you launch the electron?
and somebody claims that my stationary electron's matter wave " HAVE NO MOMENTUM"...
He he :)
This is exactly what Schroedinger's equation gives you: The time-independent solution is a stationary wave without momentum. When you launch an electron through free space it cannot be modelled by Schroedinger's equation. An electron moving through free space is modelled by Maxwell's equation for the electric-potential of a light wave; except that this wave is moving at a slower speed than the speed of light c. So HA HA!!

Gilbert by the way introduced termin "transfer" something ALONG the curve, something can be mass or momentum or spin or charge or ... Can you give the definition of MOMENTUM?
Momentum is mass times speed. An atomic electron has mass-energy that is less than its rest mass, but it has no speed and therefore no momentum Ha! Ha!
johanfprins
1 / 5 (1) Aug 31, 2012
Wrong!!! I can explain it.
Of course,You can!!!By postulating and shaman guestures with a drum beating :)
Hehe
No YOU are the Voodoo expert who claims that an electron can accelerate without emitting EM radiation. This is impossible. And what is your explanation for this? That nobody can exaplain it!! Therefore it is what it is. You are really crazy you know!
Minich
not rated yet Aug 31, 2012
You are really crazy you know!
Of course, I know i am crazy.

I am crazy more than enough to be all right :)
Minich
not rated yet Aug 31, 2012
There is now cowboy AGE that every cowboy thinks that he can invent new theory of Universe, disproving everything, having cowboy brain and cowboy PhD from grungy university of grungy country.
Minich
not rated yet Aug 31, 2012
johanfprins
I think, that You are outcasted by physics community NOT by your experiments, but by you are ready to insult everybody.

May be you are greate experimenter but in quantum theory you are "full zero", excuse.
johanfprins
1 / 5 (1) Aug 31, 2012
johanfprins
I think, that You are outcasted by physics community NOT by your experiments, but by you are ready to insult everybody.

May be you are greate experimenter but in quantum theory you are "full zero", excuse.


The "full zero" excuses are all the people who blindly follow the Voodoo of "wave-particle duality", "complementarity" , Dirac's mathematical fudging, etc. And who believe in non-existent "particles" like Cooper-pairs, anyons, axions, Higgs bosons, etc. Why do people who claim that they are intelligent want to believe the mpossible? For example that 1. an electron can accelerate without emitting EM; 2. That cahrge-carriers can accelerate without an electric-field being present.
Minich
not rated yet Aug 31, 2012
I think, that Erica Carlson are pretty girl :)
ValeriaT
not rated yet Aug 31, 2012
..and godly too. A short vid of her...
johanfprins
1 / 5 (1) Sep 01, 2012
I think, that Erica Carlson are pretty girl :)

Yes she is: AND she has the experimental data that proves that all the models of superconduction based on the assumption that the charge-carriers MUST be bosons, are physics nonsense.
Minich
not rated yet Sep 01, 2012
..and godly too. A short http://vimeo.com/29587877 of her...
Thank you for link. I am poor in english and can't understand spoken english. What is the difference goodly-pretty?

In our faculty there were only 10-20% of girls and in my theoretical department http://fock.phys....x_en.htm we have NO girls those times. So my wife and first Lady of Russia Putina and President Putin and i are all alumni :)
Girls in Russia in theoretical physics are very rare cases :(
And we all in Russia think that it is very good :)
Minich
not rated yet Sep 01, 2012
I think, that Erica Carlson are pretty girl :)

Yes she is: charge-carriers MUST be bosons, are physics nonsense.
Why ask senseless questions? In superfluid behaviour the main topic is the moving of quantum matter waves with gaps in spectrum , diffraction, repellion of quantum levels and so on :)
Is it electron's matter wave or is it helium's matter wave, is all the same.
johanfprins
1 / 5 (1) Sep 02, 2012
Why ask senseless questions? In superfluid behaviour the main topic is the moving of quantum matter waves with gaps in spectrum , diffraction, repellion of quantum levels and so on :)
Is it electron's matter wave or is it helium's matter wave, is all the same.

It has all along been naive to think that liquid helium and superconducting charge-carriers follow exactly the same physics. It is a pity that Russia has caused this false legacy. The atoms within liquid helium can be accelerated: Just tip a cup and see the liquid accelerating while it falls to earth. This also means that if the atoms could have been charged, they would have been accelerated by an electric-field. The charge-carriers within a superconductor ARE charged, but they cannot be accelerated by an applied electric-field. Although quantum fluctuations do play a role in both case, it is the epitome of stupidity to think that a superconductor is the same as superfluid helium.
ValeriaT
1 / 5 (1) Sep 02, 2012
Girls in Russia in theoretical physics are very rare cases :( And we all in Russia think that it is very good :)
I don't think, it improved the quality of the Russian research very much. Maybe we should try to check some girls in your science too...
Minich
not rated yet Sep 04, 2012
To ValeriaT
I don't think that russian Jew agree with citation index :)
Our russian Jew are everywhere in all important cities of the world!!!
For example our Abramovich (Chelsy FC owner) is in London and in Chukotka, but i don't see any circle in Chukotka :)

Do not touch our girls!!! We love them! And no theoretical physics is needed for love!
Minich
not rated yet Sep 04, 2012
Why ask senseless questions? In superfluid behaviour the main topic is the moving of quantum matter waves with gaps in spectrum , diffraction, repellion of quantum levels and so on :)
Is it electron's matter wave or is it helium's matter wave, is all the same.

It has all along been naive to think that liquid helium and superconducting charge-carriers follow exactly the same physics. ...The atoms within liquid helium can be accelerated: Just tip a cup and see the liquid accelerating while it falls to earth. This also means that if the atoms could have been charged, they would have been accelerated by an electric-field. The charge-carriers within a superconductor ARE charged, but they cannot be accelerated by an applied electric-field. Although quantum fluctuations do play a role in both case, it is the epitome of stupidity to think that a superconductor is the same as superfluid helium.
You will see that You are wrong SOON :)
Better to laugh to be the last.
johanfprins
1 / 5 (1) Sep 04, 2012
You will see that You are wrong SOON :)
Better to laugh to be the last.
I am always open to be convinced: But I doubt that what YOU will consider proof will be proof: Are you again going to invoke ducks swimming on a pond? AND PLEASE JUST ACCEPT THAT THE CONCEPT OF AN "ORDER PARAMETER" IS A FUDGE: IT IS NOT RELEVANT TO ANY PHYSICS WHATSOEVER!!
johanfprins
1 / 5 (1) Sep 04, 2012
This is typical East Asian, Russian approach. We love the women, yes, but we should' allow them to do what the men are doing, because women - you know - women belong to kitchen only. Apparently the Russian physicists are guarding their job positions in research. If I consider the nonsenses, which you're spreading here all the time, I have to ask, why exactly? To cover their incompetence?


Well formulated Natello: In this case I agree with you 100% Our female physicists in the West constitute one of our greatest assets!
johanfprins
1 / 5 (1) Sep 04, 2012
Our female physicists in the West constitute one of our greatest assets!
Well, OK - but please keep on mind, I'm not friend of any gender quotas: both negatives (as Minich implies with his negativist approach), both positives (as many EU feminists are applying). In essence, the gender quotas are the sexism of the same category, like the denial of the role of women in science - just with opposite sign.

Again I agree with you. Setting quotas are nothing else but reverse discrimunation. It degrades us as human beings and it encourages mediocrity; the greatest scourge at present in physics! Why does mediocrity unify people as well as it does?
johanfprins
1 / 5 (1) Sep 04, 2012
I hope you are right: The last ten years have defintely dampen my belief that this human race will still be around in 100 years! If Physicists can be as mediocre and dogmatic as I have experienced (and they claim they are open-minded when it come to new ideas) we do not have a snowball's chance in Hell!!
johanfprins
1 / 5 (1) Sep 04, 2012
I know about your story quite well, but some reflections of yours aren't very better, regarding the dogmatism. For example your denial of the role of boson condensates and Cooper pairs in low temperature superconductivity isn't very convincing for me in this matter.
Is this official dogmatism which I am blindly advocating? Obviously not: YOU are not willing to EVEN try and think outside the boundaries of accepted dogma. What is in your mind a Bose-Einstein Condensate? Does it consist of separate Cooper pairs? It cannot: Since separate entities can be distinguished while the derivation of Bose-Einstein statistics DEMANDS that they cannot be distinguished. Thus even if Cooper pairs can exist (which is impossible) they will NOT be able to form a BEC, unless they do not exist as separate entities after they have formed this condensate. Can you not see how inconsistent you are?