ANOMALOUS MAGNETIZATION AND TORQUE DUE TO QUASI-2D BEHAVIOR IN LAYERED SUPERCONDUCTORS

Reversible magnetization and torque are calculated in uniaxial layered superconductors in the quasi-2D regime, taking into account the trapping of vortex cores between layers. An anomalous transverse magnetization appears, together with a large torque, when the field is close to the layer direction. Besides the maximum due to anisotropic 3D behaviour, both quantities exhibit a second and sharper maximum, depending on temperature and field, at a field angle corresponding to lock-in of vortices parallel to the layers. The torque should be much higher for thin slabs or films. © 1990.