Photon Interference and Temporal Entanglement: New Insights from Recent Research

Recent research by Zhaohua Tian, Qi Liu, Yu Tian, and Ying Gu, titled "Wavepacket interference of two photons through a beam splitter: from temporal entanglement to wavepacket shaping," explores the interference of two photons with different temporal shapes as they pass through a beam splitter. This study, submitted to arXiv on March 7, 2024, and last revised on August 26, 2024, investigates how the splitting ratio of the beam splitter and the temporal indistinguishability of the input photons affect the temporal entanglement, which is quantified using Von Neumann entropy.

The authors found that maximum mode entanglement can be achieved with a 50/50 beam splitter configuration. This configuration allows for the generation of a Bell state encoded in temporal modes, which is independent of the specific form of the input photons. Furthermore, the detection of one of the entangled photons at a specific time enables the probabilistic shaping of the other photon. This shaping process can transform exponentially decaying wavepackets into sine shapes and subsequently into Gaussian shapes with a fidelity exceeding 99%.

These findings have significant implications for large-scale optical quantum networks, as they may address shape mismatch issues that can arise during photon transmission. The ability to shape photons effectively could enhance the performance of quantum communication systems and improve the reliability of quantum information transfer.

For further details, the full paper can be accessed at arXiv:2403.04432.