Magic states of top quarks

Recent years have seen an increasing body of work examining how quantum entanglement can be measured at high energy particle physics experiments, thereby complementing traditional table-top experiments. This raises the question of whether more concepts from quantum computation can be examined at colliders, and we here consider the property of , which distinguishes those quantum states which lead to a genuine computational advantage over classical states when used in algorithms. We examine top-antitop pair production at the LHC, showing that nature chooses to produce magic tops, where the amount of magic varies with the kinematics of the final state. We compare results for individual partonic channels and at proton level, showing that averaging over final states typically increases magic. This is in contrast to entanglement measures, such as the concurrence, which typically decrease. Also, while some entanglement measures (e.g., the concurrence) have a nonzero threshold for entanglement, there is no such nonzero threshold for magic. Our results create new links between the quantum information and particle physics literatures, providing practical insights for further study. Published by the American Physical Society 2024