Topological properties and self-energy effects in elemental Yb

Recent theoretical calculations predict the presence of Dirac nodal lines with pi Berry phase and related topological surface states in elemental alkaline-earth metals. Here we provide experimental and theoretical evidence for the existence of similar nodal lines also in hexagonal close-packed Yb, an element of the lanthanide series, in the limit of zero spin-orbit coupling. These topological properties emerge after taking into account self-energy corrections, which permit one to correctly describe the experimental low-energy electronic structure of Yb. By angle-resolved photoemission spectroscopy we demonstrate the occurrence of topological surface states in Yb which are robust in the presence of the large spin-orbit coupling.

Automated summary

The study reveals the existence of Dirac nodal lines with pi Berry phase and related topological surface states in hexagonal close-packed Yb, an element of the lanthanide series, in the absence of spin-orbit coupling. These topological properties emerge after taking into account self-energy corrections, allowing for the correct description of the experimental low-energy electronic structure of Yb. The research also demonstrates the presence of robust topological surface states in Yb even in the presence of large spin-orbit coupling.