I Is London depth in superconductors analogous to skin depth?

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London penetration depth in superconductors and skin depth in conductors share similar mathematical formulations derived from Maxwell's equations, but they are not equivalent. The skin depth arises from dissipation effects due to finite electrical conductivity, while the London penetration depth is linked to the effective photon mass in superconductors through the Anderson-Higgs mechanism. Practically, they exhibit some similarities, yet one cannot substitute penetration depth for skin depth in electromagnetic property calculations. Superconductors at low frequencies behave like perfect conductors, with the key distinction being the presence of significant kinetic inductance in type II superconductors. Understanding these differences is crucial for accurate electromagnetic analysis in superconducting materials.
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London penetration depth that's defined for superconductors has a similar equation to skin depth in conductors derived from maxwell's equations. Are they equivalent?
 
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Yes, from a practical point of view they are somewhat similar.
However, there are not "the same thing"; you can for example not replace the skin depth by the penetration depth when e.g. calculating EM properties.
The EM properties of superconductors at low frequencies (frequencies much lower than the energy of the gap) behave pretty much like perfect conductors from a EM point of view. The main difference (for type II superconductors) is actually presence of a fairly significant kinetic inductance, rather than the penetration depth.
 
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