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Start with London's 2nd equation in Superconductivity, curl J = 1/(μ*λ²), and Ampere's curl B = μ*j.

Then we curl both side curl curl B = μ* curl J and we do the substitution.

So curl curl B = 0 - del²B which is the laplacian operator.

My question is...how to integrate it?

the equation becomes -del²B = -B/λ²

And I am not sure how to integrate it to solve for B(x). Am I supposed to?

I don't understand how the books jump to B(x) = B*exp(-x / λ)

Please help and thank you very much. Any input is much appreciated too.

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# From London Equations to Penetration Depth(Integrate Laplacian)

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