[Seminar] Electron-phonon coupling and symmetry-breaking processes in the charge-density-wave phase of metallic Kagome superconductors (2024.02.29)
- 극한양자기능물질연구센터
- Hit197
- 2024-02-22
February 29, 2024, 11:00 ~ 12:00, General Studies 51205, SKKU
Electron-phonon coupling and symmetry-breaking processes in the charge-density-wave phase of metallic Kagome superconductors
Dirk Wulferding 1 , Seungyeol Lee 2 , Youngsu Choi 3 , Soohyun Cho 4 , Qiangwei Yin 5 , Zhijun Tu 5 , Chuncheng Gong 5 , Hechang Lei 5 , Saqlain Yousuf 3 , Jaegu Song 3 , Hanoh Lee 3 , Tuson Park 3 , and Kwang-Yong Choi 3
1 IBS-Center for Correlated Electron Systems, Seoul National University, Korea
2 Department of Physics, Chung-Ang University Seoul, Korea
3 Department of Physics, SKKU Suwon, Korea
4 Shanghai Institute of Microsystem and Information Technology, Shanghai, China
5 Department of Physics, Renmin University Beijing, China
Metallic systems with flat electronic bands and Dirac points have recently gathered immense attention, as they are prone to numerous exotic and topological electronic phases and related instabilities. Particularly, the discovery of superconductivity in the layered metallic kagome compounds AV 3Sb 5 (A=Cs,K,Rb) has ignited a massive research effort to elucidate the nature and the pairing mechanism of this potential topological superconductor [1,2]. Of special relevance may be a neighboring charge-density-wave (CDW) phase – yet, its true role in establishing superconductivity in AV 3Sb 5 remains unresolved until now.
We present a comprehensive temperature and polarization resolved Raman scattering study on CsV 3Sb 5 single crystals [3]. Our highly angular-resolved Raman data sheds a light on the symmetry of CDW-related excitations and on selected phonons, which allude to an emergent C 2 symmetry within the CDW phase. This symmetry-breaking together with phonon anomalies at T CDW signify the formation of a nematic phase through a concerted interplay of electronic correlations and electron-phonon coupling within the exotic CDW phase.
[1] Ortiz, et al., Phys. Rev. Mater. 3, 094407 (2019).
[2] Ortiz, et al., Phys. Rev. Lett. 125, 247002 (2020).
[3] Wulferding, et al., Phys. Rev. Res. 4, 023215 (2022).