Why is there zero resistivity in superconductors when there is non-zero entropy?

In summary, according to the theory of superconductivity, resistivity almost zero. Below critical temperature the entropy decreases markedly with cooling. My doubt is when there is an entropy there is a disorder. then how can move conducting electron freely and zero resistivity occur ? if you know please replay.
  • #1
anuraj.b
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According to theory of superconductivity, resistivity almost zero. Below critical temperature the entropy decreases markedly with cooling .
why resistivity zero when entropy not equal to zero?
my doubt is when there is an entropy there is a disorder. then how can move conducting electron freely and zero resistivity occur ? if you know please replay
 

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  • #2
resistivity almost zero
Exactly, not almost.

why resistivity zero when entropy not equal to zero?
Where is the issue? Note that not all particles in the material contribute to superconductivity.
 
  • #3
you know when resistivity is zero then cooper electrons move freely. but the problem is the entropy not equal to zero , the atoms in the superconductor vibrate its mean position. then how can cooper electron move freely?
 
  • #5
anuraj.b said:
you know when resistivity is zero then cooper electrons move freely. but the problem is the entropy not equal to zero , the atoms in the superconductor vibrate its mean position. then how can cooper electron move freely?

You do know that the "entropy" here is the entropy of the whole material? mfb has indicated that NOT ALL ELECTRONS PARTICIPATE IN SUPERCONDUCTIVITY (sorry, I had to bold it and cap it since you appear to have missed it the first time around). So there are normal-state electrons in the material that are not part of the supercurrent.

Furthermore, superconductivity does NOT occur just at 0 K. In fact, in high-Tc superconductors, the transition temperatures can be as high as 100-130 K! The lattice still has considerable vibrations at those temperatures. So why would entropy be zero when there is a non-zero finite temperature?

You haven't made much attempt to try and connect why "zero resistance" MUST somehow imply "zero entropy". On the other hands, you'll notice that I've had to type quite a bit (more than all of your posts combined so far) in explaining to you why it can't be zero.

Zz.
 

1. What is superconductivity?

Superconductivity is a phenomenon where certain materials, when cooled below a critical temperature, have zero electrical resistance and can conduct electricity with 100% efficiency. This means that electrical currents can flow through them without any energy loss, making them extremely useful for a variety of applications.

2. How does superconductivity occur?

Superconductivity occurs when electrons in a material form pairs and move together in a coordinated way, known as Cooper pairs. This allows them to flow through the material without any resistance. This pairing is facilitated by the interaction between the electrons and the crystal lattice of the material.

3. What is the critical temperature for superconductivity?

The critical temperature for superconductivity is the temperature at which a material transitions from a normal, resistive state to a superconducting state. This temperature varies depending on the material, but for most known superconductors it is extremely low, often below -200 degrees Celsius.

4. What is entropy and its relationship to superconductivity?

Entropy is a measure of the disorder or randomness in a system. In superconductors, the entropy is extremely low due to the highly ordered state of the Cooper pairs. As a result, superconductors have very low or even zero entropy, which allows them to maintain their superconducting state at low temperatures.

5. What are the potential applications of superconductivity?

Superconductivity has many potential applications, including in energy transmission, medical imaging, and quantum computing. It has the potential to greatly increase efficiency and reduce energy loss in a variety of systems, making it a highly sought-after phenomenon in the scientific community.

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