Creating highly symmetric qudit heralded entanglement through highly symmetric graphs (2404.05273v1)

Abstract: Recent attention has turned to exploring quantum information within larger Hilbert spaces by utilizing qudits, which offer increased information capacity and potential for robust quantum communications. While the efficient generation of multipartite qudit entanglement is crucial for studying quantum correlations in high-dimensional Hilbert spaces, the increased dimension makes the circuit design challanging, especially when the entanglement is generated by heralding detections. In this work, we demonstrate that the graph picture of linear quantum networks (LQG picture) can provide a simplified method to generate qudit multipartite heralded entanglement of high symmetries. The LQG picture enables the reduction of circuit complexity by directly imposing the state symmetry onto the circuit structure. Leveraging this insight, we propose heralded schemes for generating $N$-partite $N$-level anti-symmetric (singlet) and symmetric (Dicke) states. Our study shed light on the optimal circuit design of high-dimensional entanglement with a systematic graphical strategy.