基于自由电子-光子相互作用的干涉效应产生光学猫态

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

由自由电子-光子相互作用引起的新型量子效应因其在超快量子信息处理中的潜在应用而引起了越来越多的关注.薛定谔猫态是量子信息处理中极其重要的量子资源,本文基于光子诱导近场电子显微镜提出了制备与调控含有大量光子的光学猫态的理论新方案.基于自由电子与光子间多通道相互作用的量子干涉效应,可观测到输出光场量子态的Wigncr负性随相互作用强度的振簕现象,且在Wigner负性的振荡峰值处可以实现保真度高于0.99的光学猫态.通过改变自由电子-光子间相互作用强度,以及对电子进行不同的投影测量,可以对猫态尺度等性质进行调控.本研究刻画了输出光场的精密测量能力,揭示了猫态在量子精密测量任务中的优势,加深了人们对于自由电子-光子相互作用的量子效应的认识与理解,为非经典量子态的超快制备与调控提供了全新的思路.

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.