Entanglement has a capacity to enhance imaging procedures, but this remains unexplored for attosecond imaging. Here, we elucidate that possibility, addressing orbital angular momentum (OAM) entanglement in ultrafast processes. In the correlated process non-sequential double ionization (NSDI) we demonstrate robust photoelectron entanglement. In contrast to commonly considered continuous variables, the discrete OAM allows for a simpler interpretation, computation, and measurement of entanglement. The logarithmic negativity reveals that the entanglement is robust to incoherence and an entanglement witness minimizes the number of measurements to detect the entanglement, both quantities are related to OAM coherence terms. We quantify the entanglement for a 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, well-suited to attosecond processes, and can be exploited to enhance imaging capabilities through correlated measurements, or for generation of OAM-entangled electrons.

纠缠具有增强成像过程的能力，但这对于阿秒成像来说仍未得到探索。在这里，我们阐明了这种可能性，解决了超快过程中的轨道角动量（OAM）纠缠问题。在相关过程非顺序双电离（NSDI）中，我们展示了强大的光电子纠缠。与通常考虑的连续变量相比，离散 OAM 可以更简单地解释、计算和测量纠缠。对数负性表明纠缠对于不相干性具有鲁棒性，并且纠缠见证者最大限度地减少了检测纠缠的测量次数，这两个量都与 OAM 相干项相关。我们量化一系列目标和场参数的纠缠，以找到最纠缠的光电子对。该方法提供了一种使用 OAM 量化和测量纠缠的通用方法，非常适合阿秒过程，并且可用于通过相关测量来增强成像能力，或用于生成 OAM 纠缠电子。