Bloch wave simulations in the frozen lattice approximation

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Materials Science

Background:

• Simulating thermal diffuse scattering (TDS) is crucial for understanding electron diffraction patterns.
• The frozen lattice (FL) approximation simplifies TDS simulations but requires accurate methods.
• Conventional Bloch wave methods can be computationally intensive for TDS simulations.

Purpose of the Study:

• To develop an efficient simulation method for TDS within the FL approximation.
• To reduce the computational cost of dynamical simulations in electron diffraction.
• To validate the accuracy of the proposed method against established techniques.

Main Methods:

• Modification of the conventional Bloch wave method by incorporating the classical scattering matrix method.
• Performing eigenvalue operations only once per partial incident wave using equilibrium atomic positions.
• Comparison of simulated convergent beam electron diffraction (CBED) patterns with multislice method results.

Main Results:

• Drastic reduction in calculation time due to a single eigenvalue operation per wave.
• The modified Bloch wave method accurately simulates the FL approximation.
• Simulated CBED patterns closely match those obtained via the multislice method.

Conclusions:

• The developed method provides a computationally efficient approach for simulating TDS in the FL approximation.
• Dynamical simulations based on the Bloch wave method can effectively represent the FL approximation.
• This advancement offers a faster route for analyzing electron diffraction data in materials science.