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

TL;DR

This paper proposes a scheme to generate optical cat states through quantum interference in multi-path free-electron-photon interactions, enabling high-fidelity non-Gaussian states with potential quantum advantages.

Contribution

It introduces a novel method for creating optical cat states via quantum interference in free-electron-photon interactions with strong coupling, highlighting high fidelity and controllable nonclassical states.

Findings

Wigner negativity oscillates with coupling strength

High-fidelity optical cat states are generated at oscillation peaks

Quantum interference of multiple pathways enables fast state preparation

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.