# Entangling independent particles by path identity

**Authors:** Kai Wang, Zhaohua Hou, Kaiyi Qian, Leizhen Chen, Mario Krenn, Shining Zhu, Xiao-song Ma  
**arXiv:** [2412.03022](https://arxiv.org/abs/2412.03022)  
**Date:** 2024-12-04  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2412.03022v1/

## Key points

- Quantum entanglement is a phenomenon characterized by correlations between particles that surpass classical analogues.
- Traditionally, entanglement has been achieved through local interactions or entanglement swapping techniques.
- The authors demonstrate that independent particles can be entangled without direct interaction, prior established entanglement, or Bell-state measurements by leveraging the indistinguishability of photon pair origins.
- This research challenges the belief that prior generation and measurement of entanglement are essential prerequisites for creating connections between independent particles with no shared history.
- The innovative technique presented in the paper has practical implications for quantum networks by potentially streamlining resource requirements in quantum communication systems.

## Summary

In their groundbreaking paper titled "Entangling Independent Particles by Path Identity," authors Kai Wang, Zhaohua Hou, Kaiyi Qian, Leizhen Chen, Mario Krenn, Shining Zhu, and Xiao-song Ma delve into the fascinating realm of quantum entanglement. This phenomenon is characterized by correlations between particles that surpass any classical analogues and serves as a cornerstone for both fundamental research in quantum mechanics and practical applications like quantum networks. Traditionally, achieving entanglement has relied on local interactions or entanglement swapping techniques. These methods involve generating entanglement at a distance through pre-established entanglement and Bell-state measurements. However, the specific requirements for generating quantum entanglement without conventional local interactions have remained relatively unexplored until now. The authors present groundbreaking demonstrations showcasing that independent particles can be entangled without the need for direct interaction, prior established entanglement or Bell-state measurements. This achievement is made possible by leveraging the indistinguishability of photon pair origins. By challenging the longstanding belief that prior generation and measurement of entanglement are essential prerequisites for creating connections between independent particles with no shared history, this research opens up new possibilities in the field. Beyond its foundational significance, this innovative technique has practical implications for quantum networks. By eliminating the necessity for complex photon sources and reducing overhead photon numbers, this approach could potentially streamline resource requirements in quantum communication systems. The study published in Phys. Rev. Lett. 133 (2024) sheds light on a novel pathway to harnessing quantum entanglement between independent particles through path identity, offering promising prospects for advancing both theoretical understanding and practical applications in quantum technology.