Maxwell Andrew S, Madsen Lars Bojer, Lewenstein Maciej
ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860, Castelldefels, Barcelona, Spain.
Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark.
Nat Commun. 2022 Aug 10;13(1):4706. doi: 10.1038/s41467-022-32128-z.
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，但这在阿秒成像中仍未得到探索。在此，我们阐明了这种可能性，探讨了超快过程中的轨道角动量（OAM）纠缠。在关联过程非顺序双电离（NSDI）中，我们展示了稳健的光电子纠缠。与通常考虑的连续变量不同，离散的OAM允许对纠缠进行更简单的解释、计算和测量。对数负性表明该纠缠对非相干性具有稳健性，并且一个纠缠见证者可将检测纠缠所需的测量次数减至最少，这两个量都与OAM相干项相关。我们对一系列目标和场参数的纠缠进行了量化，以找到纠缠度最高的光电子对。这种方法提供了一种利用OAM来量化和测量纠缠的通用方法，非常适合阿秒过程，并且可通过关联测量来增强成像能力，或用于生成OAM纠缠电子。
