STABILITY LIMIT OF SUPERHEATED MEISSNER STATE DUE TO 3-DIMENSIONAL FLUCTUATIONS OF ORDER PARAMETER AND VECTOR POTENTIAL

We have calculated near the transition temperature Tc the upper experimental magnetic field Hu at which the metastable, superheated Meissner state becomes unstable against infinitesimally small fluctuations of the order parameter and the vector potential. For κ≤1.10, the stability limit is determined by fluctuations of infinite wavelength, and the field Hu coincides with the maximum field Hsh at which solutions of the Ginzburg-Landau equations cease to exist. For κ>1.10, the stability limit is determined by fluctuations of finite wavelength, and the value of Hu is smaller than Hsh. For example, at κ4.25, HuH1, and when κ→, HuHc0.745 (Hc is the thermodynamic critical field). For κ1.10, one finds within 1% accuracy HuHc=(135)[1+(2κ)-12]. © 1969 The American Physical Society.