Violations of a Leggett-Garg inequality without signaling for a photonic qutrit probed with ambiguous measurements

Wang, Kunkun; Emary, Clive; Xu, Mengyan; Zhan, Xiang; Bian, Zhihao; Xiao, Lei; Xue, Peng

Abstract

We realize a quantum three-level system with photons distributed among three different spatial and polarization modes. Ambiguous measurements of the state of the qutrit are realized by blocking one out for the three modes at any one time. Using these measurements we construct a test of a Leggett-Garg inequality as well as tests of no-signaling-in-time for the measurements. We observe violations of the Leggett-Garg inequality that cannot be accounted for in terms of signaling. Moreover, we tailor the qutrit dynamics such that both ambiguous and unambiguous measurements are simultaneously nonsignaling, which is an essential step for the justification of the use of ambiguous measurements in Leggett-Garg tests.

Citation

Wang, K., Emary, C., Xu, M., Zhan, X., Bian, Z., Xiao, L., & Xue, P. (2018). Violations of a Leggett-Garg inequality without signaling for a photonic qutrit probed with ambiguous measurements. Physical Review A, 97(2), Article 020101(R). https://doi.org/10.1103/PhysRevA.97.020101

• Journal Article Type: Article
• Acceptance Date: Nov 14, 2017
• Online Publication Date: Feb 5, 2018
• Publication Date: Feb 5, 2018
• Deposit Date: Jun 27, 2018
• Publicly Available Date: Jul 2, 2018
• Journal: Physical Review A
• Print ISSN: 2469-9926
• Electronic ISSN: 2469-9934
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 97
• Issue: 2
• Article Number: 020101(R)
• DOI: https://doi.org/10.1103/PhysRevA.97.020101
• Keywords: Quantum benchmarking; Quantum information processing; Quantum information
• Public URL: https://hull-repository.worktribe.com/output/897368
• Publisher URL: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.97.020101