A quantitative comparison between iterative and non-iterative phase retrieval for non-collinear spin textures visualized with Lorentz microscopy

Phase contrast imaging with electron holography takes advantage of the wave properties of coherent electrons and their interaction with electromagnetic fields, e.g., matter. In comparison to conventional microscopy, it provides an enhanced sensitivity and resolution and enables the visualization of spin degrees of freedom in the form of the in-plane magnetic induction. These experiments are based on the detection of the electron phase using off-axis or in-line holography. The former requires a biprism, the latter works in Fresnel mode/Lorentz mode with post processing involving a phase retrieval algorithm, such as transport-of-intensity or Gerchberg-Saxton. In this talk, I will discuss the strength of both iterative and non-iterative algorithms through application to modeled and real materials systems hosting non-collinear spin textures. One focus will be on chiral spin textures in amorphous materials where exit wave reconstruction allows to disentangle electrostatic, magnetization, and magnetic field contributions to the phase shift.