Experimental observation and spin texture of Dirac node arcs in tetradymite topological metals

TL;DR

This paper reports the discovery of Dirac node arcs with unique spin textures in tetradymite topological metals, revealing their fundamental topological properties and spin characteristics in these materials.

Contribution

It provides the first experimental observation of spin textures in Dirac node arcs across all compounds in the tetradymite M$_2$Te$_2$X family, highlighting their simplicity and topological significance.

Findings

Presence of non-trivial spin textures in Dirac node arcs.

Dirac node arcs are found in all studied tetradymite compounds.

These states are the simplest example of a type-I Dirac system with a single spin-polarized node arc.

Abstract

We report the observation of a non-trivial spin texture in Dirac node arcs, novel topological objects formed when Dirac cones of massless particles extend along an open one-dimensional line in momentum space. We find that such states are present in all the compounds of the tetradymite M$_2$Te$_2$X family (M$=$Ti, Zr or Hf and X$=$P or As), regardless of the weak or strong character of the topological invariant. The Dirac node arcs in tetradymites are thus the simplest possible, textbook example, of a type-I Dirac system with a single spin-polarized node arc.