The Dirac nodal line network in non-symmorphic rutile semimetal RuO$_2$
arXiv:1908.02621
The authors use angle-resolved photoemission spectroscopy to map the Fermi surface of RuO₂, revealing a network of two Dirac nodal lines and a third robust nodal line near the Fermi level that generates a tunable flat‑band surface state on the (110) surface.
Abstract
We employ angle resolved photoemission spectroscopy (ARPES) to investigate the Fermi surface of RuO$_2$. We find a network of two Dirac nodal lines (DNL) as previously predicted in theory, where the valence- and conduction bands touch along continuous lines in momentum space. In addition, we find evidence for a third DNL close to the Fermi level which appears robust despite the presence of significant spin orbit coupling. We demonstrate that the third DNL gives rise to a topologically trivial flat-band surface state (FBSS) at the (110) surface. This FBSS can be tuned by surface doping and presents an interesting playground for the study of surface chemistry and exotic correlation phenomena.
12 pages, 9 figures