the data processing package for (tr)ARPES data
In a photoemission process, an extreme UV or X-ray photon liberates an electron from the confines of the electronic potential within the material. ARPES directly measures the electronic energy and momentum parallel to the surface of the sample under study to infer the electronic states of the material. For a tutorial review on ARPES and its applications in physics and material science, see here. The data structure of ARPES is a stack of 2D images measured at different sample geometries, which are used to reconstruct the full static 3D band structure of the material.
TrARPES is an emerging technique that combines state-of-the-art ultrafast laser systems (~ fs resolution) with an existing ARPES experimental setup. TrARPES studies light-induced electronic dynamics such as phase transition, exciton dynamics, reaction kinetics, etc. It adds a time dimension, usually on the order of femtoseconds to nanoseconds, to the scope of ARPES measurements. Due to complex electronic dynamics, various coupling effects between the energy and momentum dimensions come into play in time. A complete understanding of the multidimensional time series from trARPES measurements can reveal dynamic constants crucial to the understanding of material properties and aid in simulation, design and further device applications.
General data processing pipeline:¶
- Load file (Igor binary or txt files)
- Use image processing to find initial guess for fitting
- Define the fitting model (model function and regularizer)
- Carry out fitting