Anisotropy and Frequency Dependence of ac Magnetic Susceptibility of Two-Dimensional Organic Superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br under Magnetic Field

The responses to a c magnetic field for two-dimensional (2D) organic superconductor κ-(BEDT-TTF) 2 Cu[N(CN) 2 ]Br, under d c magnetic field applied perpendicular to the 2D plane, are different with respect to the frequency and orientation of the a c field. In the case of ac field applied perpendicular to the 2D plane, the frequency dependence is explained by the electromagnetic screening taking account of fluxoid dynamics and normal skin depth effects. For the a c field applied parallel to the 2D plane, the observed anisotropic behaviors are influenced by the effect of the interlayer decoupling of pancake fluxoids.