Evidence for a Dirac nodal-line semimetal in SrAs$_{3}$

TL;DR

This paper provides experimental and theoretical evidence that SrAs3 is a Dirac nodal-line semimetal, exhibiting topological quantum phenomena such as a nontrivial Berry phase and chiral anomaly.

Contribution

The study demonstrates the realization of a Dirac nodal-line semimetal in SrAs3 through combined magnetotransport measurements and first-principle calculations, confirming its topological nature.

Findings

Nontrivial pi Berry phase from quantum oscillations

Negative longitudinal magnetoresistance indicating chiral anomaly

Identification of a hole pocket enclosing loop nodes

Abstract

Dirac nodal-line semimetals with the linear bands crossing along a line or loop, represent a new topological state of matter. Here, by carrying out magnetotransport measurements and performing first-principle calculations, we demonstrate that such a state has been realized in high-quality single crystals of SrAs3. We obtain the nontrivial pi Berry phase by analysing the Shubnikov-de Haas quantum oscillations. We also observe a robust negative longitudinal magnetoresistance induced by the chiral anomaly. Accompanying first-principles calculations identify that a single hole pocket enclosing the loop nodes is responsible for these observations.