Vortex-line-lattice torque in anisotropic superconductors

We calculate the magnetic torque τ= M× H that an uniaxial superconductor feels in presence of an external magnetic field of magnitude H, oriented of an angle α with respect to its c-axis. Our simulated annealing numerical method minimize the Gibbs free energy in the London aproximation, and we assume straight vortex lines and a vortex-line lattice with only one vortex per unit cell. Here we report results near the lowest critical field region H c1.