English

Experimental demonstration of input-output indefiniteness in a single quantum device

Quantum Physics 2024-05-06 v2

Abstract

Quantum theory allows information to flow through a single device in a coherent superposition of two opposite directions, resulting into situations where the input-output direction is indefinite. Here we introduce a theoretical method to witness input-output indefiniteness in a single quantum device, and we experimentally demonstrate it by constructing a photonic setup that exhibits input-output indefiniteness with a statistical significance exceeding 69 standard deviations. Our results provide a way to characterize input-output indefiniteness as a resource for quantum information and photonic quantum technologies and enable table-top simulations of hypothetical scenarios exhibiting quantum indefiniteness in the direction of time.

Keywords

Cite

@article{arxiv.2210.17046,
  title  = {Experimental demonstration of input-output indefiniteness in a single quantum device},
  author = {Yu Guo and Zixuan Liu and Hao Tang and Xiao-Min Hu and Bi-Heng Liu and Yun-Feng Huang and Chuan-Feng Li and Guang-Can Guo and Giulio Chiribella},
  journal= {arXiv preprint arXiv:2210.17046},
  year   = {2024}
}

Comments

5 + 18 pages, 11 figures

R2 v1 2026-06-28T04:49:02.046Z