Quantum energy teleportation enabled by thermal discord

摘要

Energy teleportation with no energy carrier between two physically separated sites was demonstrated in principle by M. Hotta in 2008. His demonstration used a three-step protocol applied to a Heisenberg spin particle pair initially in its fully entangled ground state. We apply the Hotta protocol to the same Heisenberg pair but now suppose the pair is, more generally, in a thermal state, introducing temperature as an explicit parameter. These thermal states show a degree of quantum correlation (thermal discord) at all temperatures. We find that at any temperature energy teleportation is possible with the Hotta protocol, even at temperatures beyond the threshold where the particles' entanglement vanishes. This shows that entanglement is not fundamentally necessary for energy teleportation; quantum discord generally can suffice. It is also a new instance in which quantum dissonance (discord without entanglement) is seen to act as a quantum resource.