Gaussian resource based heralded entangled state generation enhanced by photon addition and subtraction

We propose a heralded entanglement generation scheme based on Gaussian sources augmented with photon addition and subtraction operations. By combining single-mode squeezing, linear interferometers, and conditional photon-number measurements on ancillary modes, our model probabilistically generates dual-rail encoded Bell, GHZ, and W states. We systematically optimize the squeezing parameters and interferometer settings to maximize both the heralding success probability and the fidelity with the target states. Our results show that the inclusion of photon addition and subtraction significantly enhances the non-classicality of the output states, leading to improved generation performance, while maintaining computational efficiency comparable to single-photon source models. We further analyze the robustness of the scheme under parameter perturbations, demonstrating stable performance against realistic experimental imperfections. This work provides a versatile and experimentally feasible framework for scalable heralded entanglement generation using Gaussian resources with non-Gaussian operations.