Speaker
Description
Angle-resolved photoemission spectroscopy (ARPES) is the most direct probe of a material’s electronic structure. ARPES has been primarily used for mapping the dis-persion and interactions of electronic states, i.e. to quantify the real and imaginary parts of the electron self-energy. A full characterization of the electronic structure, however, requires access to more subtle properties of the Bloch wave function, i.e. the orbital texture, Berry curvature, and topological invariants. This information is encoded in the matrix elements of the photoemission process and can be exposed by probing the photoemission signal while changing the photon parameters as well as the geometry of the experiment. Conceptually, this approach treats ARPES as a high-dimensional spectroscopic and interferometric technique with the signal being recorded in a high-dimensional parameter space. We demonstrate that the dependence of ARPES intensity on symmetry operations of the sample and/or the light reveals the orientation of electronic orbitals, specifically the state-dependent orbital pseudospin [1].
To harvest the information content of large-volume, multi-dimensional photoemission data, we introduce a new data format based on NeXus [2], a hierarchically organized hdf5 data structure. The aim is to immediately enable preprocessed data and metadata shareability according to FAIR data principles, employing existing public storage and archiving research data infrastructures such as Zenodo, OpenAIRE, and Nomad/ FAIRmat. Ultimately, the multidimensional photoemission spectroscopy (MPES) format is designed to allow high-performance automated access, providing experimental data¬bases for high-throughput material search. Our approach involves reaching out to the community using a web-based infrastructure with a wiki-structured documentation [3]. As a demonstrator of the potential of our approach, we present the workflow we developed for our data pipeline, originating from time-resolved ARPES [4].
References
[1] M. Schüler et al., Phys. Rev. X 12, 11019 (2022); S. Beaulieu et al., npj Quantum Materials 6, 93 (2021).
[2] M. Könnecke et al., J. Appl. Cryst. 48, 301-305 (2015) & https://www.nexusformat.org/
[3] https://mpes.science/ & https://fairmat-experimental.github.io/nexus-fairmat-proposal/
[4] R.P. Xian et al., Scientific Data 7, 442 (2020) & R.P. Xian et al., arXiv:2005.10210.
| Abstract Number (department-wise) | PC 04 |
|---|---|
| Department | PC (Wolf) |
