Vortices in d-wave superconductors

We determine the vortex structure in d-wave superconductors with tetragonal (D-4h) and orthorhombic (D-2h) symmetry on the basis of Ginzburg-Landau theory. For the tetragonal symmetry, a d-wave vortex drives an s-wave component with a characteristic fourfold structure, comprising four off-center vortices on each of the half-axes and a counter-rotating central vortex. Decreasing the Ginzburg-Landau parameter below the critical value kappa=2 leads to the collapse of the off-center vortices. An orthorhombic distortion modifies this structure significantly, with 6, 4, 2, or 0 off-center induced s-wave vortices present, depending on the magnitude of the distortion.