English

Fermiology and spin polarization of topological surface states in PtBi$_2$

Superconductivity 2026-07-02 v1 Strongly Correlated Electrons
Authors: Anders Christian Mathisen , Xin Liang Tan , Stefanie Suzanne Brinkman , Kristian Mæland , Fabian Göhler , Øyvind Finnseth , Grigory Shipunov , Falk Pabst , Manuel Alonso Lemos , Balasubramanian Thiagarajan , Craig Polley , Björn Trauzettel , Anna Isaeva , Jorge I. Facio , Hendrik Bentmann
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Abstract

Layered PtBi2_2 is a candidate for topological superconductivity arising in Fermi-arc surface states. Using spin- and angle-resolved photoemission spectroscopy, we demonstrate that the Fermi arcs in PtBi2_2 are singly degenerate and spin-polarized, which establishes their nontrivial topology and constitutes a necessary condition for topological superconductivity. We further uncover a pronounced surface-termination dependence of the Fermi-arc dispersion, yielding either nearly flat or approximately linear bands in agreement with first-principles calculations. Together, the observed spin polarization and termination-dependent bandwidth of the Fermi-arc surface states identify key ingredients underlying the potential emergence of topological superconductivity in PtBi2_2.

Keywords

topological superconductivity Fermi arcs spin polarization angle-resolved photoemission spectroscopy PtBi2 surface states

Cite

@article{arxiv.2607.01947,
  title  = {Fermiology and spin polarization of topological surface states in PtBi$_2$},
  author = {Anders Christian Mathisen and Xin Liang Tan and Stefanie Suzanne Brinkman and Kristian Mæland and Fabian Göhler and Øyvind Finnseth and Grigory Shipunov and Falk Pabst and Manuel Alonso Lemos and Balasubramanian Thiagarajan and Craig Polley and Björn Trauzettel and Anna Isaeva and Jorge I. Facio and Hendrik Bentmann},
  journal= {arXiv preprint arXiv:2607.01947},
  year   = {2026}
}