Anisotropy parameters of superconducting

Data on macroscopic superconducting anisotropy of MgB 2 are reviewed. The data are described within a weak coupling two-gaps anisotropic s-wave model of super-conductivity. The calculated ratio of the upper critical fields γ H = H c2,ab /H c2,c increases with decreasing temperature in agreement with available data, whereas the calculated ratio of London penetration depths γ λ = λ c /λ ab decreases to reach ≈ 1.1 at T = 0. Possible macroscopic consequences of γ λ = γ H are discussed.