Experimental evidence of crystal symmetry protection for the topological nodal line semimetal state in ZrSiS

TL;DR

This study provides experimental evidence that crystal symmetry protection is crucial for the stability of the topological nodal line semimetal state in ZrSiS, demonstrated through pressure-induced phase transition experiments.

Contribution

The paper presents combined experimental and theoretical evidence showing how symmetry breaking affects the topological phase in ZrSiS, highlighting the role of crystal symmetry protection.

Findings

Pressure induces a topological phase transition in ZrSiS.

Symmetry breaking via lattice distortions affects the topological state.

Experimental evidence supports the role of crystal symmetry in topological protection.

Abstract

Tunable symmetry breaking plays a crucial role for the manipulation of topological phases of quantum matter. Here, through combined high-pressure magneto-transport measurements, Raman spectroscopy, and X-ray diffraction, we demonstrate a pressure-induced topological phase transition in nodal-line semimetal ZrSiS. Symmetry analysis and first-principles calculations suggest that this pressure-induced topological phase transition may be attributed to weak lattice distortions by non-hydrostatic compression, which breaks some crystal symmetries, such as the mirror and inversion symmetries. This finding provides some experimental evidence for crystal symmetry protection for the topological semimetal state, which is at the heart of topological relativistic fermion physics.