Explanation

An important parameter of superconductors, which represents the length of external magnetic field that can penetrate into the superconducting body. London penetration depth is the attenuation constant of the magnetic induction intensity from the superconductor surface to the body as an exponential attenuation according to the London equation; Li.=(It is called a symbol?? is the concentration of superconducting electrons and is related to temperature, so it is also related to temperature. The London equation does not consider the correlation between electrons, so AL is not completely consistent with the experiment. Pippard considered this factor, and the penetration depth à P given is consistent with the experiment.

Classification