Magnetic-Field—Induced One-Dimensional Behavior in the Specific-Heat Transition in Dirty Bulk Superconductors

The specific heat is calculated in the transition region for an extreme type-II bulk superconductor [zero-temperature Ginzburg-Landau (GL) coherence length $\xi \mathrm{}\left(0\right)\mathrm{}\approx 48$ Å, dirtiness parameter $\frac{{\xi }_0}{l}\approx 120$, GL parameter $\kappa \approx 67$] for various values of applied magnetic field $H$, and compared with previously published data. Nonlocality is neglected and the quartic term in the GL free-energy functional is treated in a Hartree approximation. The calculated and measured transitions broaden with increasing $H$, the latter in a manner suggestive of an approach to the theoretically predicted one-dimensional form.