# Question about boundary condition related to vector potential

Dear all

Hi. I am trying to solve time-dependent ginzburg landau equation of 2D superconductor. When I try to solve this problem, I encounter some problem.

Basically, the boundary condition for the vector potentials is as follows;

I am not sure how can I deal with this type of boundary condition in FreeFEM++.

Thank you!

Sincerely
Daehan

Well, in the Ampère Maxwell equation, you integrate by part vA\cdot\nabla\times\nabla\times A (here vA is the test function), to get the boundary term. There replace the \nabla\times A by the desired value of the magnetic field…This gives something like this in your weak form in freefem

-int1d(Th,boundaryLBL)( (vAxN.y-vAyN.x)*(Bext) )

hope this helps,
julien

1 Like

Thank you so much! It would work!