However, in contrast to the usual (single-particle) Schrödinger equation, in which \(|\psi |\) is determined by the normalization condition, the Cooper pair condensate density \(n = |\psi |^2\) is det...However, in contrast to the usual (single-particle) Schrödinger equation, in which \(|\psi |\) is determined by the normalization condition, the Cooper pair condensate density \(n = |\psi |^2\) is determined by the thermodynamic balance of the condensate with the ensemble of “normal” (unpaired) electrons, which plays the role of the uncondensed part of the particles in the usual Bose-Einstein condensate – see Sec.