Vortex state of nano-scaled superconducting complex structures (d-dot)

Using the finite element method we have solved the Ginzburg-Landau equation for several nano-scaled composite structures with s- and d-wave superconductors, which is called d-dot, and we have obtained the superconducting state and the magnetic field distribution under zero magnetic field. For the right triangle and the square shaped d-dot, the magnetic field is induced broadly along the hypotenuses, which is different from the case of the corner junction and the square d-dot. And we show possibility of the manipulation of the magnetic flux structure by the external field or the electric current.