Fig. 1

Existence of triply degenerate fermion points in the high-temperature phase of YbPtBi from DFT and ARPES. a Bulk band structure of YbPtBi from DFT calculations along the [111] direction. Blue curves are doubly degenerate Λ₆ states, while the red and cyan curves represent the non-degenerate hole states. A comparison is shown between (b) ARPES measurements and (c) projected bulk band structure calculations, which are in good agreement. The comparison was made for the Yb-terminated (111) surface along the in-plane \({\bar{\mathrm \Gamma }} - \bar M\) direction (\([11\bar 2]\)). The flat f bands at energies of −0.9 and −2.1 eV are the surface f bands from the topmost Yb layer (Supplementary Fig. 12), which are not taken into account by the bulk DFT calculations