Entanglement properties of optical coherent states under amplitude damping

Abstract

Through concurrence, we characterize the entanglement properties of optical coherent-state qubits subject to an amplitude damping channel. We investigate the distillation capabilities of known error-correcting codes and obtain upper bounds on the entanglement depending on the nonorthogonality of the coherent states and the channel damping parameter. This work provides a full quantitative analysis of these photon-loss codes which are naturally reminiscent of the standard qubit codes against Pauli errors.