"Despite the great knowledge we have gained about the properties of superconductors, there are still large gaps in understanding the reasons why different materials become, under certain conditions, superconductors, or how they do so," says Prof. Zeldov.
Here is a recipe for a levitating magnet: take a lump of ceramic material with a little oxidized copper in it, cool it to 169 degrees Celsius below zero, place the magnet carefully over the material, free your hands and enjoy. This breathtaking operation convinces everyone who visits the laboratory of Prof. Eli Zaldov in the Department of Condensed Matter Physics at the Weizmann Institute of Science, of the magic of superconductivity. However, the importance of the phenomenon stems, of course, not only from its ability to produce "tricks" such as floating magnets. Quite a few devices today are based on the superconductivity feature. From electronic filters in cell phone switchboards and trains moving at high speed as they hover above the tracks, to MRI systems used for research and medical diagnosis.
"Despite the great knowledge we have gained about the properties of superconductors, there are still large gaps in understanding the reasons why different materials become, under certain conditions, superconductors, or how they do so," says Prof. Zeldov.
One of the facts already known to scientists is that magnetic fields can disrupt and destroy the superconductivity of the material. Therefore, superconductors "protect themselves" by rejecting any external magnetic field to which they are exposed - a phenomenon called the "Meissner effect". However, some types of superconductors allow a magnetic field to penetrate them while retaining their superconducting property. They do this by breaking up the penetrating field into small "islands" which take the form of tube-like vortices. In such a situation, the superconductivity is destroyed in the center of the vortex, but preserved outside it. Here a difficulty arises due to the fact that the eddies move in the presence of an electric current - a movement that causes resistance to the current. Thus the eddies damage the superconductivity of the material, making it only slightly more efficient than a normal copper wire (conductor). One way to prevent this unwanted process, and block the motion of the vortices, is to fix them to defects in the superconductor. When well-designed defects are introduced into a superconductor, the current flows more efficiently.
Magnetic fields are a necessary component in most applications of superconductors. Therefore, a complete understanding of the underlying physics of turbulence is of great practical importance. Recently, a group of scientists from Stanford University, including a graduate of the Feinberg seminary, Dr. Ofir Auslander, and Prof. Zaldov, who was there on sabbatical year, succeeded in developing a new and unique method, which allows scientists to examine the eddies closer than ever before. In this way, they managed to reveal new data on the structure and dynamics of the eddies, and on the microscopic defects that fix them.
The unique method developed by the team of scientists, which was recently published in the scientific journal Nature Physics, is based on an atomic force microscope. Using the microscope's tiny magnetic needle, the scientists were able not only to measure the physical properties of a single vortex, but also to manually change its position within the superconductor. Thus they showed that by investigating the changes occurring in a single vortex it is possible to understand the interrelationship between the vortices and the defects in the superconductor.
These insights, concerning the small details, make it possible to create a "broad picture" of the behavior of superconductors - which is necessary for their effective technological application. The research of Prof. Zeldov and his partners has already led to a number of surprising results, concerning one of the most studied superconductors, which is made of a substance called YBCO. Through the study of individual vortices, the researchers showed that the internal structure of matter is much more diverse than previously thought. Other interesting findings are related to the movement of the eddies. Thus, for example, it was discovered that shaking the vortex during its movement allows it to be moved much larger distances. These findings may be important for understanding the behavior of vortices in the presence of an electric current. The important advantage of the new method is its ability to obtain information about what is happening inside the superconductor, in contrast to other methods that only allow studying the surface. However, many of the research findings are not quite clear, and additional tests are needed - on which the scientists are currently working. In addition, despite the advantages of the atomic force microscope, its use is an invasive measurement - because the tiny magnetic needle reacts with the vortices in the material. Prof. Zeldov and the members of the research group he heads at the Weizmann Institute of Science are now looking for non-invasive ways to perform measurements and changes of individual vortices, hoping to advance the understanding of the behavior of superconductors one step further.
19 תגובות
Call the phone number found on the Nell website, you might be the one to fly at the speed of light.
Your explanation is only true for what you think, but Kim has created another theory for you and even you are not close to knowing what a super king is even though you studied at the university. It seems that the one who wrote the title will announce what the answer to the superconductor is, he has the knowledge to build a superconductor that will cause a flying saucer to fly close to the speed of light from the phone number 0523813060 not on Shabbat
Your explanation is only true for what you think, but Kim has created another theory for you and even you are not close to knowing what a super king is even though you studied at the university. It seems that the one who wrote the title will announce what the answer to the superconductor is, he has the knowledge to build a superconductor that will cause a flying saucer to fly close to the speed of light from the phone number 0523813060 not on Shabbat
Your explanation is only true for what you think, but Kim has created another theory for you and even you are not close to knowing what a super king is even though you studied at the university. It seems that the one who wrote the title will announce what the answer to the superconductor is, he has the knowledge to build a superconductor that will cause a flying saucer to fly close to the speed of light from the phone number 0523813060 not on Shabbat
An old man becomes young. It should be noted that the theory of the magnetic field around the plate is offered for construction to anyone who is interested. Here it is instead of flying at the speed of light, the atoms rotate around the plate, therefore there is no need to fly at the speed of light, one must be young. I have a house in Shuvi for a million and a half shekels, make me young and the house will be yours. Reply to this opinion.
A very interesting theory - the one who successfully builds the flying saucer will be the worst overnight, every company will want rights to the invention.
Write on the Google website - a real flying saucer - a theory of how to surround the flying saucer with a magnetic field of tremendous strength, see a construction plan.
Ehud, a classic model of a resistless conducting material is not the same in its properties as a superconductor. The Meissner effect and the whole topic of magnetic vortices presented in this article would not exist in such a model.
To Avi Blizovsky
Thanks.
And if you're already talking to him, maybe you'll ask him that the flash ad of the busy back or whatever it is every time.
Make sure it doesn't jump from the right side of the screen to the left side.
It covers the entire comment column in its left half.
I'm not the only one this happens to him. And this is in Microsoft's patch browser. Including all the updates..
I will ask the technical manager to add a textual link below the image on the right
to the creature
The observed phenomena of superconductivity can be easily explained by classical physics, it is simply necessary to assume
Because there is a conductive material without resistance. The problem begins when looking for the microscopic model underlying the phenomenon. It took 46 years to explain "normal" conductivity. The best minds worked on the problem without success - Einstein, Feynman, Landau and more. The macroscopic model was finally proposed by Bardin Cooper and Schriefer
(BCS) after which the model is named. Regarding superconductivity at high temperatures, the explanation has not yet been found...
To Mr. Avi Blizovsky.
When there is a logo of the Weizmann Institute on the side I would expect to get there and not for you to keep clicking on your website.
So where should you look for the link besides Google?
It's like the children's riddle in the newspaper where the link is hidden.
On any normal website, a writer's credit leads to all his articles on that website. After all, this is what surfers are intuitively looking for. Even in the articles of the science site published in YNET there is no link to the science site in the credit but in separate links. And is the PC.CO.IL portal a cheap site?
Click on my name there and you will see that you will reach the list of my articles on the same site and not, for example, on the science site.
To Mr. Avi Blizovsky.
And if all the links are like that, is that encouraging in your opinion?
Why can't you be like any other normal site and give a normal link to things in the name of Omram.
You're not a site that sells things by force, and you certainly don't want to be compared to cheap sites of this type, or maybe you are.
It's annoying and a shame because I really don't feel like wandering around like this here.
Ami:
To expand on my father's words - the link you see there is a link to The writer and points to all the articles published by the science site from the pen of that writer.
In Dr. Assaf Rosenthal's articles, for example, you will find a link to Assaf Rosenthal's articles on the Hidan website.
It really matters....???- Tesla (Nicola) achieved achievements with conductors and superconductors to levels that we are probably still far from in some ways - the great inventions were sabotaged because of economic considerations.
Scientists often deal so vigorously with such particular problems just to give the great minds something to deal with at a time when mainly what is being spread is the false religion that fills such large parts of the supposedly science at its disposal at times.
The escape from understanding to science is a serious disease in our world, the false religion continues,
Good Day
If you check, you will see that all the links to all the magazines point to their articles on the science website. Not only the Weizmann Institute magazine. There is a separate link to the sites in the "content partners" section
To Mr. Belisovsky
Why is the link to Weizman directed back to your site?
Do you think this way you will catch more surfers?
It's annoying.
To what extent can superconductivity be explained by relying on classical electromagnetism?