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Role of Sb in the superconducting kagome metal CsV$_3$Sb$_5$ revealed by its anisotropic compression
by Alexander A. Tsirlin, Pierre Fertey, Brenden R. Ortiz, Berina Klis, Valentino Merkl, Martin Dressel, Stephen D. Wilson, Ece Uykur
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Submission summary
| Authors (as registered SciPost users): | Alexander Tsirlin |
| Submission information | |
|---|---|
| Preprint Link: | https://arxiv.org/abs/2105.01397v2 (pdf) |
| Date submitted: | 2021-08-03 10:30 |
| Submitted by: | Tsirlin, Alexander |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Experimental, Computational |
Abstract
Pressure evolution of the superconducting kagome metal CsV$_3$Sb$_5$ is studied with single-crystal x-ray diffraction and density-functional band-structure calculations. A highly anisotropic compression observed up to 5 GPa is ascribed to the fast shrinkage of the Cs-Sb distances and suppression of Cs rattling motion. This prevents Sb displacements required to stabilize the three-dimensional charge-density-wave (CDW) state and elucidates the disappearance of the CDW already at 2 GPa despite only minor changes in the electronic structure. At higher pressures, vanadium bands still change only marginally, whereas antimony bands undergo a major reconstruction caused by the gradual formation of the interlayer Sb-Sb bonds. Our results highlight the central role of Sb atoms in the stabilization of a three-dimensional CDW and re-entrant superconductivity of a kagome metal.
Current status:
Reports on this Submission
Report #2 by Anonymous (Referee 1) on 2021-12-9 (Invited Report)
- Cite as: Anonymous, Report on arXiv:2105.01397v2, delivered 2021-12-09, doi: 10.21468/SciPost.Report.4017
Strengths
1. A potentially useful contribution to the growing field of Kagome materials.
2. Detailed discussion of DFT results
Weaknesses
A rather technical work, which in present form is difficult to read for a non-specialist.
Report
Please note that I am a condensed matter theorist, and not an expert in DFT, so it is hard for me to judge the validity or importance of the paper for the DFT community.
In terms of the relevance to condensed matter theory and experiment, the results presented in the paper may be useful, given that there is a general interest in Kagome materials.
However, the main outcome of the paper regarding the importance of the contribution of Sb atoms to the band structure, etc. seems to be rather limited, and this point alone may not be sufficient to pass the threshold in terms of acceptance criteria of this journal.
general remarks:
The authors say: "Therefore, chemical pressure has only a minor effect on the low-temperature behavior. In contrast, changes induced by hydrostatic pressure are drastic." Would it be possible to add a discussion on why there is such a difference in the effect of chemical pressure vs hydrostatic pressure, and perhaps give other examples of materials which show similar behaviour.
Requested changes
In my opinion the paper would benefit from including an introduction on the physics of Kagome metals, more detailed discussion of the results in terms of their comparison with other materials, e.g. Fe-based superconductors (mentioned in the paper), and in general putting the results into broader perspective.
Report #1 by Anonymous (Referee 2) on 2021-11-29 (Invited Report)
- Cite as: Anonymous, Report on arXiv:2105.01397v2, delivered 2021-11-29, doi: 10.21468/SciPost.Report.3957
Strengths
1- Comparatively compact paper on comparison between high pressure structure experiment and bandstructure calculation
2- Well written, clear message
Weaknesses
1- Findings of limited relevance
Report
Authors report their findings regarding the structural response of CsV3Sb5 on high hydrostatic pressure. The results are discussed in terms of the bandstructure calculated as function of pressure. The authors find good agreement between anomalies in their structural study and the disappearance of a charge densitiy/reappearance of superconductivity. Very straightforward message, although in the end the conclusion that standard bandstructure calculations work, and that you need to consider all atoms in a material if you to really understand its properties. Still, paper meets criteria regarding scientific validity and relevance and should essentially be published as is.
Requested changes
1- The authors should note the temperature, at which the high pressure experiments have been performed.
2- The authors should note and possibly discuss if the supposedly high (room) temperature affects material properties. Are there low temperature structural data?