Würzburg ToCoTronics Colloquium

The layered intermetallic PtBi₂ is attracting interest as a candidate for unconventional superconductivity, originating from Fermi-arc surface states and a bulk Weyl-semimetal state [1,2]. In this talk, I will present results from angle-resolved photoemission spectroscopy (ARPES) on the surface and bulk electronic structure of PtBi₂. I will show how the bulk Weyl physics arises from reduced translational symmetry in the Peierls-distorted crystal structure of PtBi₂. This induces pronounced redistributions of spectral weight and orbital character across the Weyl nodes. Surface-sensitive ARPES demonstrates the spin polarization and the detailed momentum distribution of the Fermi arcs for different surface terminations. We further find indications of renormalization of the Fermi-arc dispersion by electron-phonon coupling. These results underpin PtBi₂ as an interesting model system for exploring the interplay between topology and many-body interactions in quantum materials.

[1] Kuibarov et al., Nature 626, 294–299 (2024)
[2] Huang et al., arXiv:2507.13843