What is Superconductivity: Definition and 143 Discussions
Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered even down to near absolute zero, a superconductor has a characteristic critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source.The superconductivity phenomenon was discovered in 1911 by Dutch physicist Heike Kamerlingh Onnes. Like ferromagnetism and atomic spectral lines, superconductivity is a phenomenon which can only be explained by quantum mechanics. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor during its transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of perfect conductivity in classical physics.
In 1986, it was discovered that some cuprate-perovskite ceramic materials have a critical temperature above 90 K (−183 °C). Such a high transition temperature is theoretically impossible for a conventional superconductor, leading the materials to be termed high-temperature superconductors. The cheaply available coolant liquid nitrogen boils at 77 K, and thus the existence of superconductivity at higher temperatures than this facilitates many experiments and applications that are less practical at lower temperatures.
It's from this guy:
http://www.calstatela.edu/faculty/gzhao2/
It seems he published a lot of articles in respectable magazines. I'd like to know what are the opinons of you people.
He hosts a list of preprints for his articles, and you can freely look at them and analyze...
I was wondering: I have the rankings for condensed matter physics schools, but I would like to know what school is best for superconductivity research. Is it University of Maryland?
BJN
How electrons flow forever in a superconducting wire?
From where electrons getting kinetic energy?
Is this perpetual motion? if so, can we extract work and build a perpetual motion machine?
My question deals with experimentation in combining these two technologies. I think it would be a good duo, since PV's are so inefficient, and superconductivity is so efficient. I would like to know if people agree or disagree (and why), where I could find useful information on this topic...
While there seems to be a general agreement that HTSCs are d-wave, I have heard from a few places that there is still a debate as to whether HTSCs are actually a mixture of s-wave and d-wave models. Is this true?
Also, what is meant by s-wave? Is the s-wave model the BCS model (with the s...
Hi!
I was wondering if theoretical or experimental work has been done on superconductivity being created at interface between different phases?
I read a paper where they claim to have found a very thin superconducting layer between insulating oxides, but are the more sources? Especially...
Scientists using diamond anvils have found that boron in contrast to
other metals becomes superconducting at higher temperatures when
compressed:
Superconductivity: boron goes it alone.
Jul 12, 2001
"Boron - one of the lightest elements in the periodic table - becomes
a superconductor...
Today, Oct. 10 2007, marks the start of the conference at UIUC celebrating the http://www.news-gazette.com/news/local/2007/10/08/conferences_to_celebrate_physics. This news report has a good summary of the discovery and also the significance of the theory beyond just condensed matter physics...
why do different probability waves synchronize into one coherent wave at low temperatures? I'd like to research this but I don't know what this effect is called. Also, what is the quantum mechanical explanation for why the resistance in a super-conductive metal drops down to 0? Is it that the...
I apologise if this is in the wrong subforum.
I'm having a lot of trouble determining how superconductivity works in the fulleride K3C60. I've looked at so many articles that explain the debate over the mechanism (ie electron-phonon coupling and electron-electron interactions), but each...
I mentioned neutron scattering (or in particular, inelastic neutron scattering) as being one of the most important experimental technique in studying the magnetic properties of matter. This is true if the material has some ordered magnetism. This technique has been used to show the ordered...
answer me this is urgent..
can you tell me the general properties of superconductivity and applications of superconductivity?
if any websites are there,please tell me the sites i will search,i have gone through google but i couldn't get the answer.if anybody pls send it as a link...please it...
Hi, I've been working at a project on hign Tc superconductivity for a while. However, I found myself really need to gain some idea about the larger scope of this field. :confused:
Could anyone here recommend an article or a book that has a general summary for High Tc superconductivity...
could you have a long chain of c=c carbon double bonded to carbon
each carbon would be sp hybridzed, with two pi orbals bonded to adjacent carbons
c=c=c=c=c=c=c=c=c=c=c=c=c=c=c=c=c=c=c=c
going on for millions or even billions of repeating elements
which would be in resonance
c-c...
This is a chapter of a book on the history, discovery, and mechanism of superconductivity all the way to the present search on the mechanism for High-Tc superconductors.
http://arxiv.org/abs/cond-mat/0608368
Zz.
Can anyone explain or give online references that give some explanation of what d-wave superconductivity is? My (poor) understanding of it is limited to the symmetry of the gap in the first brillouin zone is such that there are 4 nodes. But does that mean there are places where the gap is...
I will admit to first being exposed to the term "room temperature superconductivity" during a pop-sci Michio Kaku interview. However, I was wondering, just what do the scientists who actually work in the field think of the possibility of room temp sc occurring in our lifetime?
Also, do you...
Hy! I made a bet with a friend. He said that at absolute zero, there is no movement so a conductor becomes an insulator (remember, it's about conductors, not semi-conductors). I say the exact opposite: because at temperatures near absolute zero a conductor becomes a super-conductor there is no...
In BCS you make the assumption that the effective electron-electron interaction is constant within a small shell around the fermi surface and zero otherwise. From this you get a constant spherical gap.
In non s-wave SC there is a specific form for the gap ie, \Delta_0 = [ \cos (k_x a) - \cos...
This is a 1922 on the Theoretical Remarks on Superconductivity. The amazing insight eventually led to the BCS theory in 1957. You wouldn't BELIEVE who the author is! I'm not going to tell you who it is. You will have to click the link to find out!
And people think he did only one thing...
Would anyone like to suggest an "easy" explanation of how superconductivity occurs? Firstly, how the Cooper pairs form and secondly why that actually results in zero resistance?
This is what I understand: An electron passes through the lattice and destorts it. This creates a region of...
I'm still reading this paper, so can't comment much on it other than to say that if there's any need to convince people that some of the most obvious quantum phenomena can be most clearly accessed via condensed matter experiments, this would be the poster child. In this particular case, it is...
Dear all:
Now I am trying hard to interpret superconductivity in MgB2, and when reading some paper such as J.Kortus et. al, J.M.An et. al on PRL/PRB, I find that their way to weigh transition temperature is different, for instance, in J.Kortus's paper(PRL86,4656(2001)), they use...
:rolleyes: :confused: How would you explain the V-I curve for High Tc supercondctors? I am reading a section on this topic although we haven ;t studied it and am confused as to how one can explain the curve?
It starts off linear then has a flat region and then is linear again.
What would...
Hello. :rolleyes:
Do some materials have a magnetic field when electricity runs through them and they are in the superconductive state?
Do they lose energy because of that field?
Thank you.
Miro
Some progress has been made in increasing the temperature at which superconductivity occurs. One material called Magnesium Boride has shown good results.
But, actually, wouldn't room temperature superconductivity violate certain physical laws, i.e., the laws of thermodynamics?
Larry
How far apart in space are these electrons?
Are the spins truly up and down or do they have the same spins (parallel)?
If they are up and down paired, then what causes that orientation?
Hey. I have a Superconductive idea. Man.
Point Symmetry.
If Symmetry point A, begins Point symmetry. Like a AB.
And a reaction is the centre of the point symmetry.
The Superconductivity could be the reaction. Either a Superconductive reaction(2A), or a Non-Superconductive reaction(2B)...
The copper-oxygen planes that
are believed to be responsible for superconductivity are separated by
many insulating layers layers. So there might not be much overlap between
atomic orbitals between separated Cu-O planes. However, electrons can
still tunnel through the insulating layers. This...
Can spin fluctuations explain superconductivity?
Hawrylak and colleagues use a magnetic field to tune their quantum dot so that the spins of electrons hopping onto or off it must be aligned up or down. This is just the kind of gate mechanism that a spintronic transistor demands - it turns...
( 1 . ) R 2 / ( I ) R 2 = 1 Dimension.
Or...
( Kinetic ) R 2 / ( Static ) R 2 = 1 Dimension.
The said, is postulate for Superconductivity, and Physics.
Here's a picture to eyeball.
OK, I would really appreciate it if somebody could explain to me as simply as possible why entanglement happens (between electrons), what a Cooper pair is, and what causes superconductivity.
I have read that if two electrons are entangled and something happens to one of them, it will affect...