Electron ptychography method and apparatus for automatically correcting mistilt of zone axis of sample

An electron ptychography apparatus for automatically correcting a mistilt of a zone axis of a sample, comprising:

• an acquisition module, configured to acquire a diffraction pattern of each scan point of the sample by scanning the sample through using the electron beam;
• a calculation module, configured to initialize an object function and an electron beam function, and construct a forward propagation model according to a propagation function between sample slices, a variable parameter of the propagation function between the sample slices comprising a tilt angle of a zone axis of the sample relative to an electron beam direction, and configured to calculate a loss function to be a difference between a calculated diffraction pattern and the acquired diffraction pattern, the calculated diffraction pattern being obtained from the forward propagation model and parameters to be optimized;
• an optimization module, configured to calculate gradients of the loss function with respect to the parameters to be optimized, respectively, and optimize the parameters to be optimized according to the gradients;
• and
• an imaging module, configured to execute the calculating the loss function of the forward propagation model, the calculating the gradients of the loss function with respect to the parameters to be optimized respectively, and the optimizing the parameters to be optimized according to the gradients, iteratively, till a termination condition for iterations is satisfied, and configured to output the optimized parameter.