Integrated Generation and Purification of Entangled Coherent States for Non-Gaussian Teleportation

TL;DR

This paper introduces an integrated photonic approach to generate and purify entangled coherent states, enabling high-fidelity non-Gaussian quantum teleportation suitable for scalable quantum networks.

Contribution

It presents a novel integrated scheme combining photon subtraction and catalysis to produce and purify entangled coherent states for improved quantum teleportation.

Findings

Teleportation fidelity for cat states exceeds classical threshold over realistic parameters.

Integrated photon subtraction and catalysis enable practical non-Gaussian entanglement generation.

The scheme is compatible with chip-scale quantum photonic architectures.

Abstract

Entangled coherent states (ECS) provide a powerful non-Gaussian resource for continuous-variable quantum communication, but their generation in scalable architectures remains challenging. We propose an integrated photonic scheme that creates high-fidelity ECS from a two-mode squeezed vacuum via photon subtraction in a symmetric waveguide trimer. The resulting non-Gaussian entanglement is further enhanced by single-photon catalysis, which purifies the distributed state after transmission through lossy channels. Using these purified ECS resources, we analyze a photon-number-based teleportation protocol and demonstrate high-fidelity transfer of both coherent states and Schrodinger cat states. In particular, the teleportation fidelity for cat states exceeds the classical threshold of 2/3 over a broad range of realistic channel and squeezing parameters, whereas Gaussian resources fail to do so. Our results show that integrated photon subtraction and catalysis enable practical, chip-compatible generation of non-Gaussian entanglement suitable for advanced quantum teleportation and continuous-variable quantum networks.