The effect of channel decoherence on entangled coherent states: A theoretical analysis

Highlights: → We analyze decoherence properties of ECSs due to channel losses. → Our result gives a new counterexample of entanglement ordering. → ECSs with sufficient small amplitudes are more robust against channel decoherence than Bell states. -- Abstract: We analyze decoherence properties of entangled coherent states due to channel losses. Employing the concept of 'entanglement of formation', degradation of fidelity and degree of entanglement are calculated. We have obtained an explicit expression of concurrence concerning the symmetric noise channel and found our result is just incompatible with that of [K. Park, H. Jeong, Phys. Rev. A 82 (2010) 062325] measured by negativity in the limit of α→0. We demonstrate that entangled coherent states with sufficient small amplitudes are more robust against channel decoherence than Bell states.