London theory, Landau theory.... and Lorentz Einstein law I am trying to learn all I can about superconductivity and discovered an interesting document in Internet. Does the Lorentz Einstein law hold true for the supercurrent : 1) of the London approach? js = ... ∂θ/∂r - A where θ is the phase and A is the EM potential vector 2) of the Landau theory? 3)of the BCS theory? One more question : does the London theory include the case of a rotating charge (gyromagnetic effect with A = ω x r)?