Computationally Efficient Handling of Partially Coherent Electron Sources in (S)TEM Image Simulations via Matrix...

Area of Science:

• Materials Science
• Physics
• Computational Science

Background:

• Simulating images in scanning/transmission electron microscopy (S/TEM) is computationally intensive.
• The mixed envelope function (MEF) is crucial for modeling partially coherent electron waves but is computationally demanding due to its 4D array structure.

Purpose of the Study:

• To develop a computationally efficient method for S/TEM image simulation.
• To reduce the time required for calculating partially coherent images by optimizing the use of the MEF.

Main Methods:

• Introduced matrix diagonalization of the mixed envelope function (MEF).
• Incorporated the electron source's finite size and energy spread into the MEF.
• Utilized eigenvectors and eigenvalues of the MEF for faster image calculations.
• Integrated the aperture function within the matrix diagonalization process.

Main Results:

• Achieved significant reduction in computation time for S/TEM image simulations.
• High accuracy was maintained by using a small number of eigenvectors.
• Enabled efficient calculation of partially coherent images by summing weighted coherent images.

Conclusions:

• Matrix diagonalization of the MEF offers a substantial improvement in computational efficiency for S/TEM image simulation.
• The method accurately models partially coherent electron beams, leading to faster and reliable image generation.
• This technique is valuable for advancing computational microscopy and materials characterization.