“…The theory agrees with experiment below ∼72 K but obviously disagrees in the range between 72 and 91 K ( T c ). Such discrepancy was commonly observed in measurements of ac magnetic responses of ultrathin SC films. ,, It is generally understood to be a 2D effect due to diffusive motion of thermally excited vortex–antivortex. , Presumably because of reduced pinning or viscosity, the vortex–antivortex excitations are more diffusive for thinner SC films. , The diffusion reduces the supercurrent induced by the applied magnetic field. − Accordingly, the diamagnetic response of the SC thin film is greatly suppressed until the temperature is sufficiently low such that the vortex–antivortex diffusive motion becomes insignificant. ,, Previous theoretical calculation and simulation have confirmed the “delayed” Meissner effect. ,, However, quantitative evaluation on the difference between T c and T * would require the knowledge of pinning energy and temperature-dependent diffusion coefficient of the vortex. , …”