Superconductors Definition and 147 Threads

Hi all, I was wondering if someone can explain to me whether: 1) Superconductors are attracted to originally unmagnetised ferromagnetic or paramagnetic materials? AIUI superconductors are perfect diamagnets due to the Meisnner Effect, and magnetic attraction is due to the creation of...

What is the speed of free electrons in vacuum, plasma and superconductors? Can we 'slow down' free electrons? Just how slow can we make electrons go?

I am curious to know the Ising model can be applied to high temperature superconducting materials. If so are there any papers significant papers on this subject that I should know about. Thanks to anyone in advance who can answer this question.

The electron pairs, acting as bosons, all fall to the lowest energy state, and can't get enough energy (under normal operating conditions), to make the quantum jump to the next energy level, hence as they move through the conductor they don't lose energy. That is, in a nutshell, my assumptions...

I've search plenty of papers,but I still got no idea about this.Can anyone give me some clues? Thanks in advance.

A classic problem in freshman electrodynamics is as follows: We have a capacitor (capacitance C1) charged up w/ charge Q, which means the energy in the system is: U_1 = \frac{Q^2}{2C_1}. We then disconnect the battery, and connect a second capacitor (capacitance C2) in parallel w/ the...

I'm unsure where this is meant to go precisely, so if needed, move this thread where necessary. Our class just touched up just slightly on BCS theory. We were told that conventional superconductors (SC) with Tc<30K were explainable by this theory, while unconventional SC's with Tc>30K...

Hi all! It's my first post. :cool: How is electrical energy sent into a superconducting loop for storage and taken out for use? Is there power loss during these actions? Peace!

anyone have equations for bitter magnets? or do i use the ones for solenoids? i need an electromagnet capable of 4T. that doesn't use super conductors >_> i have access to liquid nitrogen though.

I have an idea to build a electromagnet out of superconducting wire out of the Tl2Ba4Ca2Cu10Ox superconductor discovered earlier this year that's superconducting at 40 degrees below zero in Fahrenheit and I'm wanting to supply 1 million volts or a little more to it and see what happens. and...

Hi All I'm looking for a table of Tcs and normal state resistivities for a selection of 'typical' superconductors. I'm sure such a thing must exist in literature, but I'm having trouble locating it. Specifically, I've just finished a dissertation project developing a measurement technique...

Berkeley's Raymond Chiao has some interesting conjecture on gravity waves: http://www.technologyreview.com/blog/arxiv/23198/ According to him, it should be possible for a superconductor to reflect gravity waves like a mirror. This then leads to all sorts of interesting possibilities...

1. I have read that external magnetic fields cannot penetrate a superconductor. Why is this? 2. Does the magnetic field produced by the superconducting current extend outside of the superconductor? And if so, what happens when the magnetic field starts to collapse, can it renter the...

Hi there, This is my first post and I am guessing I should post my question here at the astrophysics section so I'm doing so (admin, if you think the topic should belong somewhere else, please move it). My question is with regards to the continued research conducted by Tajmar et al...

Could someone please explain the difference between Perfect Diamagnetism and Superconductors in terms of the Meissner Effect and the magnetic field passing through an element of the sort. Under low temperatures in perfect diamagnetic materials if there is a magnetic field it remains the same...

Hello, frineds I have a question How is it possible to get High Temperature Supercondactor produced by laser radiation? Maybe we can irradiate a target and the producing plasma will serrle down substrate Do you have an idea?

Is it possible to describe spontaneous breaking of the local gauge symmetry in the standard Hamiltonian formalism, without any manual redefinition of the gauge field( A(r) -> A(r)+▽Λ(r) )? Detailed description of my question is given below.(Quite lengthy.. sorry.) 1. By the 'standard...

Does anyone know of any practical uses for a type I superconductor, where it isn't possible to use a type II (which typically have higher critical temperatures so need less cooling etc)?

After following the thread "ideal conductor vs superconductor" a while, I am wondering about something that must have a simple answer. If you change the magnetic flux through a superconducting ring, what happens to induced emf?

Hi, everyone. In a course on superconducting materials, my lecturer has suggested that in a Type I(one) superconductor, any normalconducting region containing trapped magnetic flux will feel a Lorentz force per unit volume F_L = J \times B, where J is the transport current density (vector!)...

What are the permeability and permissivity of type I superconductors?

Hello, which theory or formalism is used to show the superconductors have zero resistance? I'd like to see some derivation from microscopic principles. For resistivity scattering is crucial so a static wavefunction doesn't offer an explanation? I read some basic BCS theory and have...

I'm trying to understand a bit more about high temperature superconductors. I'm familiar with BCS theory and a little bit about high temp superconductors, but I'm still confused about a bunch of stuff Why exactly is copper oxide used in high temperature superconductors? Why is this specific...

I don't really understand why the Fermi-Function is often used to describe superconductors. According to the BCS theory Cooper pairs should be Bosons with Spin 0. Wouldn't it make more sense to use the Bose-Einstein-Function? Thanks Tanja

I read that most type-2 superconductors have one quantum of flux (2*pi*h-bar/e) per flux filament (fluxon), but that a few have a different value (were fullerenes one of them?). I mentioned this to an professor I am doing some research for, and he challenged what I read. Now, I can't find what...

How/why does a superconductor amplify the effects of gravitomagnetism? It must have something to do with a coherent movement of subatomic particles, right?

Hi, I am doing a lab report for superconductors, and yeah, we have to bake them in a furnace and test their properties and all that. I am trying to find a nice book, something like an all in one jumble where it talks about the history, the theoretical properties (such as the Meissner effect)...

I was reading there that if you apply an electromotive force of 1 vole to a wire with a resistance of 1 ohm it will cause a current of 1 ampere to flow. If I was to obtain a wire with no resistance at all and applied 1 volt to it would it still cause a current of 1 amp to flow or would the...

http://arxiv.org/PS_cache/arxiv/pdf/0704/0704.2499v1.pdf This seems interesting, has anyone an idea about this research ?

source:British physics olymp. 1995:cool: a small slab of material is placed on a dish containing liquid nitrogen.The material is a superconductor at the temperature of liquid nitrogen.A small but strong magnet is moved near and placed over the slab.The magnet is seen to wobble but remains...

I am plotting resistance vs. thermocouple voltage (which is to be used to determine the temperature from a conversion chart) for two superconductors. I need to determine where to take the Tc value. This is difficult to determine since the "knee" is not well defined. Also, how should I guess...

This past Sept. marked the 20th anniversary of the discovery of High-Tc superconductors. It was a discovery that turns physics, and especially condensed matter physics, upside down. A subject area that was thought to be 'dead' and fully matured, where we thought we knew everything that we were...

If I were able to get a particle with mass to tunnel through a superconductor (for the sake of having a point, a long, thin, cylindrical one), would that mass's travel through the superconductor have the same equal-but-opposite-reaction effect as the same mass if it were accelerated to such...

How far are we from Room Temp SCs? Have they been invented yet? I hear you can use dynamite and that get's you close to room temperature.

This attachement was my dissertation, my final project for my BSc in physics, just would like a proffessional opinion. Best wishes newo

There is a good review article on inelastic neutron scattering experiments and results on hole-doped cuprate superconductors. One of the authors (Tranquada) was the first person to report experimentally on the possible existence of the stripe phase in such a compound using the same technique...

So we've had 20 years of high temperature superconductors and I cannot help but ask myself why isn't my power cord made out it? In all this time you would expect some kind of applications to be coming through (excepting the odd industrial application). I assume the main prolem is with the...

Hi, I have started Plysics 20 by correspondence and I can't find the answer to this question: The reason that liquid nitrogen temperature superconductors are important is that liquid nitrogen costs less than liquid helium. New technologies to store liquid helium have been developed in the...

o:) utopia: superconductors for transmission lines globally? o:) undefinedundefined i want to develop a model ,entailing all the parameters required to transmitt power using SUPERCONDUCTORS . IF ANYBODY CAN HELP ME PLEEZE POST THE NUMERICAL DATA REGD THE SAME ,this will be highly acknowledged...

Given that HTSC cables have been commercially available for some time now why has the uptake of this technology been so slow. Even allowing for the extra cost I'd have thought the advantages such as 140x the current carrying capacity, far higher efficiency etc. would outway any possible...

Okay - I understand the idea of why superconductors work (i hope i do - it was a while ago I learned it) - namely by two electrons of 1/2 integer spin obeying Fermi-Dirac statistics, forming a pair of electrons than can behave in some circumstances like a single particle with integer spin. This...

Is it possibly to make a superconductor at home ? I mean with limited funds and ... you know. Maybe this idea is a bit crazy but I'd like to know. :biggrin:

I am doing a report on superconductors. One of the ideas to support the idea of bandgaps in the superconductor is the isotope effect. Unfortentualy I have been an able to find any information on how exactly the isotope effect works. Any information would be greatly appreciated, thank you...

Superconductors can allow a current to flow indefinately. Assuming that someday room temperature superconductors are avilable, would it be possible to use them as some sort of RAM hybrid for a computer? Could information be stored indefinately, almost like using a harddrive, but much faster...

Greetings ! I'd like to ask a couple of Qs about superconductors: - Would a superconducting wire be affected by the lorentz force just like a normal current carrying wire or would the Meissner effect somehow prevent this due to the surface currents or something ? - What's the general...

What is the definiton of a high temperature superconductor otherwise known as Type II superconductors?

Hey everyone, got a quickie for u. I'm not sure if there is a proper answer for this question, but could ppl give me brief theories to why superconductors repel magnets no matter what polarity they are. thanks for any input!