Experimental demonstration of separating the wave‒particle duality of a single photon with the quantum Cheshire cat

Jia-Kun Li; Kai Sun; Yan Wang; Ze-Yan Hao; Zheng-Hao Liu; Jie Zhou; Xing-Yan Fan; Jing-Ling Chen; Jin-Shi Xu; Chuan-Feng Li; Guang-Can Guo

doi:10.1038/s41377-022-01063-5

Experimental demonstration of separating the wave‒particle duality of a single photon with the quantum Cheshire cat

Light Sci Appl. 2023 Jan 5;12(1):18. doi: 10.1038/s41377-022-01063-5.

Authors

Jia-Kun Li^{1

2

3}, Kai Sun^{4

5

6}, Yan Wang^{1

2

3}, Ze-Yan Hao^{1

2

3}, Zheng-Hao Liu^{1

2

3}, Jie Zhou⁷, Xing-Yan Fan⁷, Jing-Ling Chen⁸, Jin-Shi Xu^{9

10

11}, Chuan-Feng Li^{12

13

14}, Guang-Can Guo^{1

2

3}

Affiliations

¹ CAS Key Laboratory of Quantum Information, University of Science and Technology of China, 230026, Hefei, China.
² CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 230026, Hefei, China.
³ Hefei National Laboratory, University of Science and Technology of China, 230088, Hefei, China.
⁴ CAS Key Laboratory of Quantum Information, University of Science and Technology of China, 230026, Hefei, China. ksun678@ustc.edu.cn.
⁵ CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 230026, Hefei, China. ksun678@ustc.edu.cn.
⁶ Hefei National Laboratory, University of Science and Technology of China, 230088, Hefei, China. ksun678@ustc.edu.cn.
⁷ Theoretical Physics Division, Chern Institute of Mathematics, Nankai University, 300071, Tianjin, China.
⁸ Theoretical Physics Division, Chern Institute of Mathematics, Nankai University, 300071, Tianjin, China. chenjl@nankai.edu.cn.
⁹ CAS Key Laboratory of Quantum Information, University of Science and Technology of China, 230026, Hefei, China. jsxu@ustc.edu.cn.
¹⁰ CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 230026, Hefei, China. jsxu@ustc.edu.cn.
¹¹ Hefei National Laboratory, University of Science and Technology of China, 230088, Hefei, China. jsxu@ustc.edu.cn.
¹² CAS Key Laboratory of Quantum Information, University of Science and Technology of China, 230026, Hefei, China. cfli@ustc.edu.cn.
¹³ CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 230026, Hefei, China. cfli@ustc.edu.cn.
¹⁴ Hefei National Laboratory, University of Science and Technology of China, 230088, Hefei, China. cfli@ustc.edu.cn.

Abstract

As a fundamental characteristic of physical entities, wave‒particle duality describes whether a microscopic entity exhibits wave or particle attributes depending on the specific experimental setup. This assumption is premised on the notion that physical properties are inseparable from the objective carrier. However, after the concept of the quantum Cheshire cats was proposed, which makes the separation of physical attributes from the entity possible, the premise no longer holds. Furthermore, an experimental demonstration of the separation of the wave and particle attributes inspired by this scenario remains scarce. In this work, we experimentally separated the wave and particle attributes of a single photon by exploiting the quantum Cheshire cat concept for the first time. By applying a weak disturbance to the evolution of the system, we achieve an effect similar to the quantum Cheshire cat and demonstrated the separation of the wave and particle attributes via the extraction of weak values. Our work provides a new perspective for the in-depth understanding of wave‒particle duality and promotes the application of weak measurements in fundamentals of quantum mechanics.