Enhancing the entanglement of a teleported state by local collective noises

We show that the entanglement of the two-qubit teleported state via a class of four-qubit entangled channel states can be increased by collective amplitude damping locally acting on one part of the channel state. Specifically, we compare the entanglement contained in the output state of teleportation before and after the action of the collective amplitude damping on the channel state, and show that for a wide range of input entangled two-qubit states, the local decoherence can result in an increase in the output entanglement. In this process, the average fidelity of the teleportation is also increased. Our result reveals that some quantum properties of the four-qubit channel state are definitely improved in the process of enhancing the fidelity by local noise.