Entanglement polygon inequality in qudit systems
Xue Yang, Yan‐Han Yang, Ming‐Xing Luo · Physical Review A · 2022
Entanglement is an important resource for quantum communication tasks. Most results are focused on qubit entanglement. Our goal in this work is to characterize the multipartite high-dimensional entanglement. We first derive an entanglement polygon inequality for the $q$ concurrence, which manifests the relationship among all the ``one-to-group'' marginal entanglements in any multipartite qudit system. This implies lower and upper bounds for the marginal entanglement of any three-qudit system. We further extend our study to general entanglement distribution inequalities for high-dimensional entanglement in terms of the unified-$(r,s)$ entropy entanglement, including Tsallis entropy, R\'enyi entropy, and von Neumann entropy entanglement as special cases. These results provide insights into characterizing bipartite high-dimensional entanglement in quantum information processing.