Differential phase-contrast (DPC) scanning transmission electron microscopy (STEM) has recently attracted significant interest for allowing mapping of electrostatic and magnetic fields at a high spatial resolution. Nevertheless, due to its simultaneous sensitivity to both electrostatic and magnetic fields, the interpretation of DPC measurements on magnetic specimens is not straightforward. In this work, we demonstrate that the two contributions to the Lorentz force can be separated by means of the time-reversal operation of the electron beam. In practice, such a condition is easily achieved by repeating the DPC-STEM measurement after flipping the specimen by 180°. The separation of the two contributions allows discriminating the effects of the electrostatic potential, like, e.g., the thickness variation in a specimen with a uniform composition, from the actual magnetic signal. This methodology is particularly relevant for the study of the magnetic nanostructure by DPC-STEM or, more generally, by 4D-STEM.

中文翻译：

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在差分相衬STEM中通过时间反转操作解开纳米级电场和磁场

差分相差（DPC）扫描透射电子显微镜（STEM）最近引起了人们极大的兴趣，他们希望以高空间分辨率绘制静电场和磁场。然而，由于其同时对静电和磁场敏感，因此对磁性样品上DPC测量的解释并不简单。在这项工作中，我们证明可以通过电子束的时间反转操作来分离对洛伦兹力的两个贡献。实际上，通过将样本翻转180°后重复进行DPC-STEM测量，可以轻松实现这种条件。两种贡献的分离允许区分静电势的影响，例如，具有均匀成分的样品的厚度变化，从实际的磁信号。该方法学与通过DPC-STEM或更普遍地通过4D-STEM进行的磁性纳米结构的研究特别相关。