Technical advances paired with developments in methodology have enabled electron microscopy to reach atomic resolution. Further improving the information limit in microscopic imaging requires further improvements in methodology. Here we report a ptychographic method that describes the object as the sum of discrete atomic-orbital-like functions (for example, Gaussian functions) and the probe in terms of aberration functions. Using this method, we realize an improved information limit of microscopic imaging, reaching down to 14 pm. High-quality probes and objects contribute to superior signal-to-noise ratios at low electron doses, allowing for relaxation of the sample thickness restriction to 50 nm for dense materials. Additionally, our method has the capability to decompose the total phase into element components, revealing that the information limit is element dependent. With enhanced spatial resolution, signal-to-noise ratio and thickness threshold compared with conventional ptychography methods, our local-orbital ptychography may find applications in atomic-resolution imaging of metals, ceramics, electronic devices or beam-sensitive material.

技术进步与方法论的发展相结合，使电子显微镜能够达到原子分辨率。进一步提高显微成像的信息限制需要进一步改进方法。在这里，我们报告了一种叠层记录方法，该方法将物体描述为离散原子轨道类函数（例如高斯函数）和像差函数方面的探测器的总和。使用这种方法，我们实现了显微成像的信息限制的改进，可以达到下午 14 点。高质量的探针和物体有助于在低电子剂量下实现卓越的信噪比，从而将致密材料的样品厚度限制放宽至 50 nm。此外，我们的方法能够将总相分解为元素分量，揭示信息限制是元素相关的。与传统的叠层成像方法相比，我们的局域轨道叠层成像技术具有更高的空间分辨率、信噪比和厚度阈值，因此可以在金属、陶瓷、电子设备或光束敏感材料的原子分辨率成像中找到应用。