Generating optical cat states via quantum interference of multi-path free-electron-photons interactions

Feng-Xiao Sun; Yiqi Fang; Qiongyi He; Yunquan Liu

doi:10.1016/j.scib.2023.06.006

Generating optical cat states via quantum interference of multi-path free-electron-photons interactions

Sci Bull (Beijing). 2023 Jul 15;68(13):1366-1371. doi: 10.1016/j.scib.2023.06.006. Epub 2023 Jun 12.

Authors

Feng-Xiao Sun¹, Yiqi Fang², Qiongyi He³, Yunquan Liu⁴

Affiliations

¹ State Key Laboratory for Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics, & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China; Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China.
² State Key Laboratory for Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics, & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China.
³ State Key Laboratory for Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics, & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China; Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China; Peking University Yangtze Delta Institute of Optoelectronics, Nantong 226010, China; Hefei National Laboratory, Hefei 230088, China. Electronic address: qiongyihe@pku.edu.cn.
⁴ State Key Laboratory for Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics, & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China; Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China; Peking University Yangtze Delta Institute of Optoelectronics, Nantong 226010, China; Beijing Academy of Quantum Information Sciences, Beijing 100193, China. Electronic address: Yunquan.liu@pku.edu.cn.

PMID: 37353435
DOI: 10.1016/j.scib.2023.06.006

Abstract

The novel quantum effects induced by the free-electron-photons interaction have attracted increasing interest due to their potential applications in ultrafast quantum information processing. Here, we propose a scheme to generate optical cat states based on the quantum interference of multi-path free-electron-photons interactions that take place simultaneously with strong coupling strength. By performing a projection measurement on the electron, the state of light changes significantly from a coherent state into a non-Gaussian state with either Wigner negativity or squeezing property, both possess metrological power to achieve quantum advantage. More importantly, we show that the Wigner negativity oscillates with the coupling strength, and the optical cat states are successfully generated with high fidelity at all the oscillation peaks. This oscillation reveals the quantum interference effect of the multiple quantum pathways in the interaction of the electron with photons, by that various nonclassical states of light are promising to be fast prepared and manipulated. These findings inspire further exploration of emergent quantum phenomena and advanced quantum technologies with free electrons.

Keywords: Cat states; Free-electron–photons interactions; Quantum interference; Ultrafast.