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Journal article
Roton pair density wave in a strong-coupling kagome superconductor
Nature (London), Vol.599(7884), pp.222-228
29/Sep/2021
PMID: 34587621
Abstract
The transition metal kagome lattice materials host frustrated, correlated and topological quantum states of matter1,2,3,4,5,6,7,8,9. Recently, a new family of vanadium-based kagome metals, AV3Sb5 (A = K, Rb or Cs), with topological band structures has been discovered10,11. These layered compounds are nonmagnetic and undergo charge density wave transitions before developing superconductivity at low temperatures11,12,13,14,15,16,17,18,19. Here we report the observation of unconventional superconductivity and a pair density wave (PDW) in CsV3Sb5 using scanning tunnelling microscope/spectroscopy and Josephson scanning tunnelling spectroscopy. We find that CsV3Sb5 exhibits a V-shaped pairing gap Δ ~ 0.5 meV and is a strong-coupling superconductor (2Δ/kBTc ~ 5) that coexists with 4a0 unidirectional and 2a0 × 2a0 charge order. Remarkably, we discover a 3Q PDW accompanied by bidirectional 4a0/3 spatial modulations of the superconducting gap, coherence peak and gap depth in the tunnelling conductance. We term this novel quantum state a roton PDW associated with an underlying vortex–antivortex lattice that can account for the observed conductance modulations. Probing the electronic states in the vortex halo in an applied magnetic field, in strong field that suppresses superconductivity and in zero field above Tc, reveals that the PDW is a primary state responsible for an emergent pseudogap and intertwined electronic order. Our findings show striking analogies and distinctions to the phenomenology of high-Tc cuprate superconductors, and provide groundwork for understanding the microscopic origin of correlated electronic states and superconductivity in vanadium-based kagome metals.
Details
- Title
- Roton pair density wave in a strong-coupling kagome superconductor
- Creators
- Hui Chen - Chinese Academy of SciencesHaitao Yang - Chinese Academy of SciencesBin Hu - Chinese Academy of SciencesZhen Zhao - Chinese Academy of SciencesJie Yuan - Chinese Academy of SciencesYuqing Xing - Chinese Academy of SciencesGuojian Qian - Chinese Academy of SciencesZihao Huang - Chinese Academy of SciencesGeng Li - Chinese Academy of SciencesYuhan Ye - Chinese Academy of SciencesSheng Ma - Chinese Academy of SciencesShunli Ni - Chinese Academy of SciencesHua Zhang - Chinese Academy of SciencesQiangwei Yin - Renmin University of ChinaChunsheng Gong - Renmin University of ChinaZhijun Tu - Renmin University of ChinaHechang Lei - Renmin University of ChinaHengxin Tan - 972WIS_INST___90Sen Zhou - University of Chinese Academy of SciencesXiaoli Dong - Chinese Academy of SciencesChengmin Shen - Chinese Academy of SciencesBinghai Yan - 972WIS_INST___90Ziqiang Wang (Corresponding Author) - Boston CollegeHong-Jun Gao (Corresponding Author) - Chinese Academy of Sciences
- Resource Type
- Journal article
- Publication Details
- Nature (London), Vol.599(7884), pp.222-228; 29/Sep/2021
- Number of pages
- 16
- Language
- English
- DOI
- https://doi.org/10.1038/s41586-021-03983-5
- PMID
- 34587621
- Grant note
- These authors contributed equally: Hui Chen, Haitao Yang, Bin Hu. We thank I. Zeljkovic, S. Wilson, J. Yin and Z.-X. Zhao for helpful discussions. The work is supported by grants from the National Natural Science Foundation of China (61888102, 52022105, 11974422, 51771224 and 11974394), the National Key Research and Development Projects of China (2016YFA0202300, 2017YFA0206303, 2018YFA0305800 and 2019YFA0308500) and the Chinese Academy of Sciences (XDB28000000, XDB30000000, XDB33030100 and 112111KYSB20160061). Z.W. is supported by the US DOE, Basic Energy Sciences grant no. DE-FG02-99ER45747.
- Record Identifier
- 993320871603596
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