To explain the observations, the theoretical team developed a coupled superconductor–vacuum-field framework based on Ginzburg–Landau theory and cavity quantum electrodynamics, explicitly incorporating the spatially nonuniform modes of the dark cavity. The theory shows that virtual-photon exchange with the cavity can renormalize the superconducting free energy and thereby stabilize the superconducting state. When the characteristic energy of the cavity mode matches the low-energy fluctuation scal