Faithful and efficient hyperentanglement purification for spatial-polarization-time-bin photon system

Abstract

Abstract We present a faithful and efficient hyperentanglement purification protocol (hyper-EPP) for nonlocal two-photon systems in spatial-polarization-time-bin hyperentangled Bell states. As the single-photon detectors can detect and herald the undesirable properties caused by the side leakage and the finite coupling strength, the parity-check gates and SWAP gates of our hyper-EPP in the spatial, the polarization, and the time-bin modes degrees of freedom (DoFs) work faithfully. The qubit-flip errors on photon systems in three DoFs can be corrected effectively with the faithful parity-check gates and the photon pairs can reuse to distill high-fidelity ones by introducing the faithful SWAP gates, which greatly increases the efficiency of our hyper-EPP. Further, the maximal hyperentanglement can be obtained in principle by operating the hyper-EPP multiple rounds.