The relation between the quantum discord and quantum teleportation: The physical interpretation of the transition point between different quantum discord decay regimes
1 Department of Theoretical Physics, Wrocław University of Technology - 50-370 Wrocław, Poland
2 Institute of Physics, Polish Academy of Sciences - 02-668 Warsaw, Poland
Received: 21 May 2015
Accepted: 23 September 2015
We study quantum teleportation via Bell-diagonal mixed states of two qubits in the context of the intrinsic properties of the quantum discord. We show that when the quantum-correlated state of the two qubits is used for quantum teleportation, the character of the teleportation efficiency changes substantially depending on the Bell-diagonal-state parameters, which can be seen when the worst-case-scenario or best-case-scenario fidelity is studied. Depending on the parameter range, one of two types of single-qubit states is hardest/easiest to teleport. The transition between these two parameter ranges coincides exactly with the transition between the range of classical correlation decay and quantum correlation decay characteristic for the evolution of the quantum discord. The correspondence provides a physical interpretation for the prominent feature of the decay of the quantum discord.
PACS: 03.65.Ud – Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.) / 03.65.Yz – Decoherence; open systems; quantum statistical methods / 03.67.-a – Quantum information
© EPLA, 2015