Comment on "Fully gapped superconductivity and topological aspects of the noncentrosymmetric superconductor TaReSi"

TL;DR

This paper challenges previous claims by showing that the stable low-temperature structure of TaReSi is Cm, not Ima2, and that the topological properties may originate from this stable noncentrosymmetric structure.

Contribution

It corrects the structural understanding of TaReSi at low temperature, identifying the stable Cm phase as the true structure responsible for topological features.

Findings

Ima2 structure is unstable at low temperature for TaReSi.

The stable structure is Cm, which is noncentrosymmetric.

Topological properties likely originate from the Cm structure.

Abstract

In a recent paper [T. Shang et al., Phys. Rev. B 107, 224504 (2023)], the authors study the physical properties of TaReSi compounds having Ima2 structure. This noncentrosymmetric structure is proposed to be the source of topological properties for mentioned compound. However, for a correct description of topological features, it is important to recognize the correct structure of the compound at low temperature. In this Comment, we show that Ima2 cannot be realized by TaReSi and is unstable at low temperature. The Ima2 structure contains the soft modes at S (1/2,0,0) point, which leads to the stable structure with Cm symmetry. Notably, the stable Cm system also has a noncentrosymmetric structure, which can be the actual source of topological properties.