  A thermodynamically stable vortex-antivortex pattern has been revealed in
mesoscopic type I superconducting triangles, contrary to type II
superconductors where similar patterns are unstable. The stable
vortex-antivortex "molecule" appears due to the interplay between two factors:
a repulsive vortex-antivortex interaction in type I superconductors and the
vortex confinement in the triangle.
