Manipulation of entanglement sudden death in an all-optical experimental setup

Entanglement sudden death (ESD) is the phenomenon wherein a multipartite entangled state disentangles in finite time even when individual qubits decohere only asymptotically in time due to noise. Prolonging the entanglement is essential for the practical realization of entanglement-based quantum information and computation protocols. For this purpose, local NOT operation in the computational basis on one or both qubits has been proposed to combat the amplitude damping noise. Here, we aim to discuss an all-optical-experimental implementation of the NOT operations that can hasten, delay, or avert ESD, all depending on when it is applied during the process of decoherence for the polarization entangled photonic qubit system[1]. Further, the preparation and characterization of a polarization entangled photon source instrumental in obtaining the exciting experimental results on the manipulation of ESD along with the attendant theory will be presented.
Reference [1]: Ashutosh Singh, Siva Pradyumna, A. R. P. Rau, and Urbasi Sinha, "Manipulation of entanglement sudden death in an all-optical setup," J. Opt. Soc. Am. B 34, 681-690 (2017).