A grip/handle and coming out of it is a sword long blade made out of atoms, now of course this would break apart very easily but what if it was indestructible? What would happen if you slice people in half? Would it slice atoms apart even? I really think if you try to cut something it wouldn't fall off.
if it sliced atoms it wouldn't be very useful as it would cause a nuclear reaction killing anything in the vicinity for several thousand years. BTW, we have quantum computers (made of atoms), and they need to be kept near absolute zero, so atom swords, nope.
...The weapon consisted of a blade of pure plasma emitted from the hilt and suspended in a force containment field. The field contained the immense heat of the plasma, protecting the wielder, and allowed the blade to keep its shape.
Actually, that still means I was wrong, because plasma is still a form of matter.