Data for Entanglement of Orbital Angular Momentum in Non-Sequential Double Ionization

Data for publication “Entanglement of Orbital Angular Momentum in Non-Sequential Double Ionization”, available at https://arxiv.org/abs/2111.10148. A readme.txt file is included with the data. Authors Andrew S. Maxwell, Lars Bojer Madsen, Maciej Lewenstein Abstract We address orbital angular momentum (OAM) entanglement in ultrafast processes. In the strongly correlated process of non-sequential double ionization (NSDI) we demonstrate robust photoelectron entanglement. In contrast to commonly considered continuous variable  entanglement measures, the discrete OAM allows for a simpler interpretation, computation, and measurement of entanglement. The logarithmic negativity reveals that the entanglement is robust to incoherent effects and an entanglement witness is used to minimize the number of measurements to detect the entanglement, while both quantities can be directly related to coherence terms between OAM channels. We quantify the entanglement for a large range of targets and field parameters to find the most entangled photoelectron pairs. This methodology provides a general way to use OAM to quantify and measure entanglement that is well-suited to attosecond processes, and we show can be exploited to enhance imaging capabilities through correlated measurements, or could be used for generation of OAM-entangled electrons.