Abstract: Penetration-depth in two-band superconductors MgB₂ is calculated by using two-band GL theory. It can be found that the ratio (γ_λ) of penetration-depth in c direction and in ab plane enhances with the increase of temperature. With the proper parameters, the theoretical result is in agreement with the experimental result at high temperature. γ_λ in the dirty limit is also discussed.

Key words: two-band superconductors, GL theory, MgB₂, penetration depth

摘要： 用两带各向异性GL(Ginzburg-Landau)模型计算了两带超导体MgB₂的穿透深度，结果表明MgB₂在c方向的穿透深度与ab平面内的穿透深度的比值（γ_λ）随温度的升高而变大，当选取适当的参数时，在高温区理论结果与实验结果符合的很好。另外还讨论了在脏极限下γ_λ的情况。

关键词: 两带超导体, GL理论, MgB₂, 穿透深度