Quantum interference between light sources separated by 150 million kilometers

Yu-Hao Deng, Hui Wang, Xing Ding, Z.-C. Duan, Jian Qin, M.-C. Chen, Yu He, Yu-Ming He, Jin-Peng Li, Yu-Huai Li, Li-Chao Peng, E. S. Matekole, Tim Byrnes, C. Schneider, M. Kamp, Da-Wei Wang, Jonathan P. Dowling, Sven Höfling, Chao-Yang Lu, Marlan O. ScullyJian-Wei Pan

Research output: Contribution to journalArticlepeer-review

54 Citations (Scopus)


We report an experiment to test quantum interference, entanglement and nonlocality using two dissimilar photon sources, the Sun and a semiconductor quantum dot on the Earth, which are separated by ~150 million kilometers. With quantum erasure techniques applied to all degrees of freedom of the otherwise vastly distinct photons, we observe time-resolved two-photon quantum interference with a raw visibility of 0.796(17), well above the 0.5 classical limit, providing the first evidence of quantum nature of thermal light. Further, using the photons with no common history, we demonstrate post-selected two-photon entanglement with a state fidelity of 0.826(24), and a violation of Bell’s inequality by 2.20(6). The experiment can be further extended to a larger scale using photons from distant stars, and open a new route to quantum optics experiments at an astronomical scale.
Original languageEnglish
Article number080401
Number of pages7
JournalPhysical Review Letters
Issue number8
Early online date21 Aug 2019
Publication statusPublished - 23 Aug 2019


Dive into the research topics of 'Quantum interference between light sources separated by 150 million kilometers'. Together they form a unique fingerprint.

Cite this