Magnitude and anisotropy of the penetration depth in high-temperature superconductors
Pokrovskii V. L
The quasi-2D nature of the superconductivity makes it possible to calculate the penetration depth ì near the transition temperature and to evaluate the anisotropy of this depth. The depth λ turns out to be 3400 A for YBa2Cu307 and 4300 A for La! 85 Sr015 Cu04. The ratio of effective masses lies between 30 and 70. The Ginzburg number is no less than 0.07 for the yttrium superconductor and no less than 0.11 for the lanthanum superconductor.