2018年10月4日
Evidence of a structural quantum critical point in (CaxSr1-x)(3)Rh4Sn13 from a lattice dynamics study
PHYSICAL REVIEW B
- 巻
- 98
- 号
- 16
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1103/PhysRevB.98.161103
- 出版者・発行元
- AMER PHYSICAL SOC
Approaching a quantum critical point (QCP) has been an effective route to stabilize superconductivity. While the role of magnetic QCPs has been extensively discussed, similar exploration of a structural QCP is scarce due to the lack of suitable systems with a continuous structural transition that can be conveniently tuned to 0 K. Using inelastic x-ray scattering, we examine the phonon spectrum of the nonmagnetic quasiskutterudite (CaxSr1-x)(3)Rh4Sn13, which represents a precious system to explore the interplay between structural instabilities and superconductivity by tuning the Ca concentration x. We unambiguously detect the softening of phonon modes around the M point on cooling towards the structural transition. Intriguingly, at x = 0.85, the soft mode energy squared at the M point extrapolates to zero at (-5.7 +/- 7.7) K, providing the first compelling microscopic evidence of a structural QCP in (CaxSr1-x)(3)Rh4Sn13. The enhanced phonon density of states at low energy provides the essential ingredient for realizing strong-coupling superconductivity near the structural QCP.
- リンク情報
-
- DOI
- https://doi.org/10.1103/PhysRevB.98.161103
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000446400600001&DestApp=WOS_CPL
- URL
- https://link.aps.org/article/10.1103/PhysRevB.98.161103
- URL
- http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevB.98.161103/fulltext
- ID情報
-
- DOI : 10.1103/PhysRevB.98.161103
- ISSN : 2469-9950
- eISSN : 2469-9969
- Web of Science ID : WOS:000446400600001