Quantum zero point electromagnetic energy difference between the superconducting and the normal phase in a high- superconducting metal bulk sample

We provide a methodological approach to the estimate of the change of the quantum vacuum electromagnetic energy density in a high critical temperature superconducting metal bulk sample, when it undergoes the transition in temperature, from the superconducting to the normal phase. The various contributions to the Casimir energy in the two phases are highlighted and compared. While the transverse magnetic polarization of the vacuum mode allows for a macroscopic description of the superconducting transition, the changes in the transverse electric vacuum mode induced by the superconductive correlations are introduced within a microscopic model, which does not explicitly take into account the anisotropic structure of the material.