I have been reading about quantum entanglement, and I was wondering what quantum states can be "sent" using entanglement. I know you can measure the spin of one of the particles, and know the spin of the other, but can you also do this with other quantum states, such as polarization, or energy?
Also, could you theoretically entangle molecules, or even larger structures? What is happening in this field of physics?
Finally, if you were able to measure the energy levels of the entangled particles, when you changed the energy state of one of the particles, would the other? Could this violate the first law of thermodynamics, or is the change so small that it does not matter, since this is the quantum world?