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arXiv · 1811.07526

Experimental transmission of quantum information using a superposition of causal orders

Yu Guo·Xiao-Min Hu·Zhi-Bo Hou·Huan Cao·Jin-Ming Cui·Bi-Heng Liu·Yun-Feng Huang·Chuan-Feng Li·Guang-Can Guo·Giulio Chiribella
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Abstract

Communication in a network generally takes place through a sequence of intermediate nodes connected by communication channels. In the standard theory of communication, it is assumed that the communication network is embedded in a classical spacetime, where the relative order of different nodes is well-defined. In principle, a quantum theory of spacetime could allow the order of the intermediate points between sender and receiver to be in a coherent superposition. Here we experimentally realise a table-top simulation of this exotic possibility on a photonic system, demonstrating high-fidelity transmission of quantum information over two noisy channels arranged in a superposition of two alternative causal orders.

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Yu Guo, Xiao-Min Hu, Zhi-Bo Hou, Huan Cao, Jin-Ming Cui, Bi-Heng Liu, Yun-Feng Huang, Chuan-Feng Li, Guang-Can Guo, Giulio Chiribella. 2020-01-19. Experimental transmission of quantum information using a superposition of causal orders. https://doi.org/10.1103/physrevlett.124.030502

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