Pressure effects on the lattice vibrations and ultrafast photocarrier dynamics in 2H-TaS2

doi:10.1063/5.0018615

	Pressure effects on the lattice vibrations and ultrafast photocarrier dynamics in 2H-TaS2
	Zhang, Kai 1; Jiang, Huachao 1; Yang, Jin 1; Zhang, Jie 1; Zeng, Zhi 1; Chen, Xiaojia 1,2; Su, Fuhai 1
刊名	APPLIED PHYSICS LETTERS
	2020-09-08
卷号	117
ISSN号	0003-6951
DOI	10.1063/5.0018615
通讯作者	Su, Fuhai(fhsu@issp.ac.cn)
英文摘要	Vibrational properties and ultrafast photocarrier dynamics of 2H-TaS2 under pressures are studied by the experiments of Raman scattering and femtosecond time resolved spectroscopy. With increasing pressure, the linewidth of two-phonon Raman mode broadens, especially features with a sudden rapid increase above 10GPa. Meanwhile, the ultrafast dynamics show that the fast decay through optical phonon scattering is significantly suppressed in amplitude and prolonged in lifetime; however, the weight of the slow decay component originating from acoustic phonon scattering is enhanced at high pressures. Furthermore, the electron-phonon (e-ph) coupling constant, lambda (q), and the density of states (DOS) near the Fermi level, N(0), are evaluated qualitatively, which reveals a drastic decrease in e-ph coupling strength and a sudden increase in the DOS beyond 10GPa. This turning pressure is consistent with the critical point where T c of superconductivity peaks while the charge density wave (CDW) vanishes, indicating the direct correlations between lambda (q), N(0), superconductivity, and the CDW under pressure. The anomaly of the DOS may imply the occurrence of a topological transition of the electronic structure. Our work not only provides valuable information for the understanding of competition between the CDW and superconductivity in 2H-TaS2 but also may open up a routine to unveil the pressure-induced electronic topological transition.
资助项目	National Natural Science Foundation of China[11774354] ; National Natural Science Foundation of China[51672279] ; National Natural Science Foundation of China[51727806] ; National Natural Science Foundation of China[11874361] ; Science Challenge Project[TZ2016001] ; CAS Innovation Grant[CXJJ-19-B08] ; CASHIPS Director's Fund[YZJJ201705]
WOS关键词	RAMAN-SCATTERING ; PHONON DYNAMICS ; TRANSITION ; ELECTRON ; TEMPERATURE ; RELAXATION ; METAL
WOS研究方向	Physics
语种	英语
出版者	AMER INST PHYSICS
WOS记录号	WOS:000571938500002
资助机构	National Natural Science Foundation of China ; Science Challenge Project ; CAS Innovation Grant ; CASHIPS Director's Fund
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/104238]
专题	中国科学院合肥物质科学研究院
通讯作者	Su, Fuhai
作者单位	1.Chinese Acad Sci, HFIPS, Inst Solid State Phys, Key Lab Mat Phys, Hefei 230031, Peoples R China 2.Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Kai,Jiang, Huachao,Yang, Jin,et al. Pressure effects on the lattice vibrations and ultrafast photocarrier dynamics in 2H-TaS2[J]. APPLIED PHYSICS LETTERS,2020,117.
APA	Zhang, Kai.,Jiang, Huachao.,Yang, Jin.,Zhang, Jie.,Zeng, Zhi.,...&Su, Fuhai.(2020).Pressure effects on the lattice vibrations and ultrafast photocarrier dynamics in 2H-TaS2.APPLIED PHYSICS LETTERS,117.
MLA	Zhang, Kai,et al."Pressure effects on the lattice vibrations and ultrafast photocarrier dynamics in 2H-TaS2".APPLIED PHYSICS LETTERS 117(2020).