Connection to quantum-geometric tensor

Quantum geometic tensor (QGT) determines numerous critical properties of quantum materials, with its imaginary part being the Berry curvature. Obtaining a connection beteween QTG and ARPES is a hard problem that requires deep understanding of the physics of photoemission that is based on the multiple scattering theory. Our work focuses on establishing ways to extract intial state spin-polarization and orbital angular momentum from spin-polarized and circular-dichroic ARPES spectra.

Experimental derivation of the quantum geometric tensor required the knowledge of the electronic wave functions of the system. In the tight-binding picture this means the knowledge of band energies together with their orbital and spin characters.

In the case of WTe₂ and PtTe₂ we demonstrated a non-trivial connection between the photoemission inital state and the spin-polarized ARPES (spin-ARPES) maps. In the case of graphene we disentangled the physics of circular-dichroic ARPES (CD-ARPES), combining the tight-binding toy-model with the real-space photoeletron diffraction computations. We applied conclusions from this model to explain rapid momentum-space variations of CD-ARPES from WSe₂.

We discuss the tactics to extract orbtal and spin characters from spin- and CD-ARPES, which will allow experimental access to the quantum geometric tensor.

Publications

M. Qahosh, M. Masilamani, H. Boban, Xiao Hou, G. Bihlmayer, Y. Mokrousov, W. Karain, J. Minar, F. Reinert, J. Schusser, C. M. Schneider, L. Plucinski, Spin-orbital mixing in the topological ladder of the two-dimensional metal PtTe2, arXiv:2502.10865 (2025)

Honey Boban, Mohammed Qahosh, Xiao Hou, Tomasz Sobol, Edyta Beyer, Magdalena Szczepanik, Daniel Baranowski, Simone Mearini, Vitaliy Feyer, Yuriy Mokrousov, Keda Jin, Tobias Wichmann, Jose Martinez-Castro, Markus Ternes, F Stefan Tautz, Felix Lüpke, Claus M Schneider, Jürgen Henk, Lukasz Plucinski, “Scattering makes a difference in circular dichroic angle-resolved photoemission”, Phys. Rev. B 11, 115127 (2025) https://doi.org/10.1103/PhysRevB.111.115127

Tristan Heider, Gustav Bihlmayer, Jakub Schusser, Friedrich Reinert, Jan Minár, Stefan Blügel, Claus M. Schneider, and Lukasz Plucinski, “Geometry-Induced Spin Filtering in Photoemission Maps from WTe₂ Surface States”, Phys. Rev. Lett. 130, 146401 (2023), https://doi.org/10.1103/PhysRevLett.130.146401