When the B field gets too high it breaks the superconducting state. And then the B field can exist inside the conductor. When the field increases to point where it breaks the state is this because the cooper pairs flowing near the surface experience a force on their spin and then break them apart. The force would break them apart because the spins are opposite on the electrons in the cooper pairs. If it breaks the cooper pairs at the surface does it just do this layer by layer until the state is broken? Im talking about an external B field acting on the superconductor.