A two-fold quantum delayed-choice experiment in a superconducting circuit

ORAL

Abstract

Wave-particle duality is among the most fundamental properties of quantum mechanics. We propose and experimentally demonstrate a two-fold quantum delayed-choice experiment where wave or particle nature of a superconducting interfering device can be post-selected twice after the interferometer. The wave-particle complementarity is controlled by a quantum which-path detector (WPD) in a superposition of its on and off states implemented through a superconducting cavity. The WPD projected to its on state records which-path information, which manifests the particle nature and destroys the interference associated with wave nature of the system. In our experiment, we can recover the interference signal through a quantum eraser even if the WPD has selected out the particle nature in the first round of delayed-choice detection, showing that a quantum WPD adds further unprecedented controllability to test of wave-particle complementarity through the peculiar quantum delayed-choice measurements.

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Authors

  • Yuan Xu

    • Tsinghua University

  • Ke Liu

    • Tsinghua University

  • Wang Weiting

    • Tsinghua Univ

  • Shi-Biao Zheng

    • Fuzhou University

  • Tanay Roy

    • Tata Institute of Fundamental Rsearch

  • Suman Kundu

    • Tata Institute of Fundamental Rsearch

  • Madhavi Chand

    • Tata Institute of Fundamental Rsearch

  • A. Ranadive

    • Tata Institute of Fundamental Rsearch

  • R. Vijay

    • Tata Institute of Fundamental Rsearch

  • Y. P. Song

    • Tsinghua University

  • L.-M. Duan

    • Tsinghua Univ and University of Michigan, Ann Arbor
    • Tsinghua University

  • L. Sun

    • Tsinghua University