Spin-orbital mixing in the topological ladder of the two-dimensional metal PtTe$_2$

TL;DR

This study visualizes and analyzes the topological surface states and spin polarization in PtTe₂ using advanced spin-polarized photoemission spectroscopy, revealing complex hybridization and symmetry-breaking effects.

Contribution

It introduces a comprehensive experimental approach combining spin-polarized photoemission with three-dimensional momentum imaging to probe topological properties beyond conventional methods.

Findings

Detection of multiple topological surface states including a Dirac cone at 2.3 eV

Strong hybridization between Pt and Te orbitals confirms nontrivial topology

Identification of symmetry-breaking effects influencing spin textures during photoemission

Abstract

We visualize the topological ladder and band inversions in PtTe$_2$ using spin-polarized photoemission spectroscopy augmented by three-dimensional momentum imaging. This approach enables the detection of spin polarization in dispersive bands and provides access to topological properties beyond the reach of conventional methods. Extensive mapping of spin-momentum space reveals distinct topological surface states, including a surface Dirac cone at the binding energy $E_B \sim 2.3$ eV and additional states at $E_B \sim 1.6$ eV, $E_B \sim 1.0$ eV, and near the Fermi level. The electronic structure analysis demonstrates strong hybridization between Pt and Te atomic orbitals, confirming the nontrivial topology of these surface states. Furthermore, by comparison to one-step model photoemission calculations, we identify a robust correlation between the initial-state and measured spin polarizations while revealing asymmetries in specific experimental spin textures. These asymmetries, absent in the initial states due to symmetry constraints, arise from the breaking of time-reversal symmetry during the photoemission process, emphasizing the crucial influence of symmetries on experimental signatures of topology.