Evidence for Band Renormalizations in Strong-Coupling Superconducting Alkali-Fulleride Films

doi:10.1103/PhysRevLett.130.216004

	Evidence for Band Renormalizations in Strong-Coupling Superconducting Alkali-Fulleride Films
	Zhou, J. S.1,2; Xu, R. Z.1,2; Yu, X. Q.1,2; Cheng, F. J.1,2; Zhao, W. X.1,2; Du, X.1,2; Wang, S. Z.1,2; Zhang, Q. Q.1,2; Gu, X.1,2; He, S. M.3; Li, Y. D.1,2; Ren, M. Q.1,2; Ma, X. C.1,2; Xue, Q. K.1,2; Chen, Y. L.3,4,5,6 ; Song, C. L.1,2,7; Yang, L. X.1,2,7
	2023-05-26
发表期刊	PHYSICAL REVIEW LETTERS
ISSN	0031-9007
EISSN	1079-7114
卷号	130 期号:21
发表状态	已发表
DOI	10.1103/PhysRevLett.130.216004
摘要	There has been a long-standing debate about the mechanism of the unusual superconductivity in alkali -intercalated fullerides. In this Letter, using high-resolution angle-resolved photoemission spectroscopy, we systematically investigate the electronic structures of superconducting K3C60 thin films. We observe a dispersive energy band crossing the Fermi level with the occupied bandwidth of about 130 meV. The measured band structure shows prominent quasiparticle kinks and a replica band involving the Jahn-Teller active phonon modes, which reflects strong electron-phonon coupling in the system. The electron-phonon coupling constant is estimated to be about 1.2, which dominates the quasiparticle mass renormalization. Moreover, we observe an isotropic nodeless superconducting gap beyond the mean-field estimation (2 Delta/kBTc approximate to 5). Both the large electron-phonon coupling constant and large reduced superconducting gap suggest a strong-coupling superconductivity in K3C60, while the electronic correlation effect is suggested by the observation of a waterfall-like band dispersion and the small bandwidth compared with the effective Coulomb interaction. Our results not only directly visualize the crucial band structure but also provide important insights into the mechanism of the unusual superconductivity of fulleride compounds.
关键词	Band structure Electron correlations Electron-phonon interactions Electronic structure Photoelectron spectroscopy Semiconductor doping Alkali fullerides Electron-phonon coupling constant Electronic.structure Fullerides High-resolution angle-resolved photoemission spectroscopies Quasiparticles Renormalization Strong-coupling Superconducting gaps Thin-films
URL	查看原文
收录类别	SCI ; EI
语种	英语
资助项目	National Key R&D program of China["2017YFA0304600","2022YFA1403100","2022YFA1403200"] ; National Natural Science Foundation of China["12275148","11774190"] ; Fund of Science and Technology on Surface Physics and Chemistry Laboratory[XKFZ202102]
WOS研究方向	Physics
WOS类目	Physics, Multidisciplinary
WOS记录号	WOS:001005481900008
出版者	AMER PHYSICAL SOC
EI入藏号	20232414209774
EI主题词	Bandwidth
EI分类号	712.1 Semiconducting Materials ; 716.1 Information Theory and Signal Processing ; 931.3 Atomic and Molecular Physics ; 931.4 Quantum Theory ; Quantum Mechanics ; 933 Solid State Physics
原始文献类型	Journal article (JA)
文献类型	期刊论文
条目标识符	https://kms.shanghaitech.edu.cn/handle/2MSLDSTB/316435
专题	物质科学与技术学院物质科学与技术学院_特聘教授组_陈宇林
通讯作者	Chen, Y. L.
作者单位	1.Tsinghua Univ, Dept Phys, State Key Lab Low Dimens Quantum Phys, Beijing 100084, Peoples R China 2.Frontier Sci Ctr Quantum Informat, Beijing 100084, Peoples R China 3.Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England 4.ShanghaiTech Univ, Sch Phys Sci & Technol, Shanghai 201210, Peoples R China 5.Chinese Acad Sci, Shanghai Sci Res Ctr, Shanghai 201210, Peoples R China 6.ShanghaiTech Lab Topol Phys, Shanghai 200031, Peoples R China 7.Collaborat Innovat Ctr Quantum Matter, Beijing 100084, Peoples R China
通讯作者单位	物质科学与技术学院; 上海科技大学
推荐引用方式 GB/T 7714	Zhou, J. S.,Xu, R. Z.,Yu, X. Q.,et al. Evidence for Band Renormalizations in Strong-Coupling Superconducting Alkali-Fulleride Films[J]. PHYSICAL REVIEW LETTERS,2023,130(21).
APA	Zhou, J. S..,Xu, R. Z..,Yu, X. Q..,Cheng, F. J..,Zhao, W. X..,...&Yang, L. X..(2023).Evidence for Band Renormalizations in Strong-Coupling Superconducting Alkali-Fulleride Films.PHYSICAL REVIEW LETTERS,130(21).
MLA	Zhou, J. S.,et al."Evidence for Band Renormalizations in Strong-Coupling Superconducting Alkali-Fulleride Films".PHYSICAL REVIEW LETTERS 130.21(2023).