Generalized Concentratable Entanglement via Parallelized Permutation Tests

Abstract: Multipartite entanglement is an essential resource for quantum information theory and technologies, but its quantification has been a persistent challenge. Recently, Concentratable Entanglement (CE) has been introduced as a promising candidate for a multipartite entanglement measure, which can be efficiently estimated across two state copies. In this work, we introduce Generalized Concentratable Entanglement (GCE) measures, highlight a natural correspondence to quantum Tsallis entropies, and conjecture a new entropic inequality that may be of independent interest. We show how to efficiently measure the GCE in a quantum computer, using parallelized permutation tests across a prime number of state copies. We exemplify the practicality of such computation for probabilistic entanglement concentration into W states with three state copies. Moreover, we show that an increased number of state copies provides an improved error bound on this family of multipartite entanglement measures in the presence of imperfections. Finally, we prove that GCE is still a well-defined entanglement monotone as its value, on average, does not increase under local operations and classical communication (LOCC).