Batch fitting benchmark -- photoemission spectroscopy
======================================================


Outline
########


The aim of the benchmark is to reconstruct the energy dispersion of tungsten diselenide (:math:`\mathrm{WSe}_2`) in the solid state from 3D photoemission band mapping (PBM) experiments or from synthetic data of similar nature. Experimental PBM data for :math:`\mathrm{WSe}_2` are obtained from either experiment [1] or model-based synthesis [2]. The three dimensions in the dataset include the two momentum components (:math:`k_x, k_y`) and the energy (:math:`E`) of the photoemitted electrons (**photoelectrons**). The spectra used in the batch fitting are the intensity profiles (:math:`I(E)`) of the photoelectron as a function of momentum (or **energy distribution curve**), :math:`I(E, k_x, k_y)`. Example scripts are included under the `/benchmarks <https://github.com/mpes-kit/pesfit/tree/master/benchmarks>`_ folder of the package.

1. ``01_WSe2_Kpoint.py`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/01_WSe2_Kpoint.py>`_)

Contains a full script with the option to run on the command line for batch fitting the photoemission data around the :math:`K` point of :math:`\mathrm{WSe}_2`. The following bash scripts contain numerical experiments for tuning the energy shift hyperparameters associated with each energy band.

* ``WSe2_Kpoint_recon_02.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/WSe2_Kpoint_recon_02.sh>`_) -- energy shift hyperparameter tuning for reconstructing energy band 1-2 of :math:`\mathrm{WSe}_2` within the corresponding energy range (used in [2])

* ``WSe2_Kpoint_recon_04.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/WSe2_Kpoint_recon_04.sh>`_) -- energy shift hyperparameter tuning for reconstructing energy band 3-4 of :math:`\mathrm{WSe}_2` within the corresponding energy range (used in [2])

* ``WSe2_Kpoint_recon_08.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/WSe2_Kpoint_recon_08.sh>`_) -- energy shift hyperparameter tuning for reconstructing energy band 5-8 of :math:`\mathrm{WSe}_2` within the corresponding energy range (used in [2])

* ``WSe2_Kpoint_recon_14.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/WSe2_Kpoint_recon_14.sh>`_) -- energy shift hyperparameter tuning for reconstructing energy band 9-14 of :math:`\mathrm{WSe}_2` within the corresponding energy range (used in [2])

* ``PES_scaling_benchmark.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/PES_scaling_benchmark.sh>`_) -- Computational scaling benchmark for an increasing number of spectral components or energy bands (used in [3])

* ``WSe2_computing_params_tuning.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/WSe2_computing_params_tuning.sh>`_) -- Tuning the task distribution parameters in parallelization (used in [3])


2. ``02_WSe2_Mpoint.py`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/02_WSe2_Mpoint.py>`_)

Contains a full script with the option to run on the command line for batch fitting the photoemission data around the :math:`M` point of :math:`\mathrm{WSe}_2`.


3. ``03_WSe2_hsymline.py`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/03_WSe2_hsymline.py>`_)

Contains a full script with the option to run on the command line for batch fitting the photoemission data around the high-symmetry line (HSL) of :math:`\mathrm{WSe}_2`. The following bash scripts contain numerical experiments for tuning the energy shift hyperparameters associated with each energy band.

* ``WSe2_hsymline_recon_02.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/WSe2_hsymline_recon_02.sh>`_) -- hyperparameter tuning for reconstructing energy band 1-2 of :math:`\mathrm{WSe}_2` within the corresponding energy range (used in [2])

* ``WSe2_hsymline_recon_04.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/WSe2_hsymline_recon_04.sh>`_) -- hyperparameter tuning for reconstructing energy band 3-4 of :math:`\mathrm{WSe}_2` within the corresponding energy range (used in [2])

* ``WSe2_hsymline_recon_08.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/WSe2_hsymline_recon_08.sh>`_) -- hyperparameter tuning for reconstructing energy band 5-8 of :math:`\mathrm{WSe}_2` within the corresponding energy range (used in [2])

* ``WSe2_hsymline_recon_14.sh`` (`link <https://github.com/mpes-kit/pesfit/blob/master/benchmarks/WSe2_hsymline_recon_14.sh>`_) -- hyperparameter tuning for reconstructing energy band 9-14 of :math:`\mathrm{WSe}_2` within the corresponding energy range (used in [2])


Usage
######

To execute the script on a local computer, one needs to download the data from the repository `pesarxiv <https://github.com/mpes-kit/pesarxiv>`_. After updating the file address within the Python scripts, they can be executed directly on the command line. For the bash scripts, one needs to change the ``PYTHONPATH`` global parameter to the corresponding address on the local computer before execution.


References
##########

| [1] J. Maklar et al., A quantitative comparison of time-of-flight momentum microscopes and hemispherical analyzers for time-resolved ARPES experiments, Revivew of Scientific Instruments `91, 123112 (2020) <https://aip.scitation.org/doi/10.1063/5.0024493>`_.
| [2] R. P. Xian, V. Stimper, M. Zacharias, et al., A machine learning route between band mapping and band structure, arXiv:`2005.10210 <https://arxiv.org/abs/2005.10210>`_.
| [3] R. P. Xian, R. Ernstorfer, P. M. Pelz, Scalable multicomponent spectral analysis for high-throughput data annotation, arXiv:`2102.05604 <https://arxiv.org/abs/2102.05604>`_.
|