Evidence chain for time-reversal symmetry-breaking kagome superconductivity

Hanbin Deng; Guowei Liu; Z. Guguchia; Tianyu Yang; Jinjin Liu; Zhiwei Wang; Yaofeng Xie; Sen Shao; Haiyang Ma; William Liège; Frédéric Bourdarot; Xiao-Yu Yan; Hailang Qin; C. Mielke III; R. Khasanov; H. Luetkens; Xianxin Wu; Guoqing Chang; Jianpeng Liu; Morten Holm Christensen; Andreas Kreisel; Brian Møller Andersen; Wen Huang; Yue Zhao; Philippe Bourges; Yugui Yao; Pengcheng Dai; Jia-Xin Yin

doi:10.1038/s41563-024-01995-w

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arXiv · 2408.02898

Evidence chain for time-reversal symmetry-breaking kagome superconductivity

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Abstract

Superconductivity and magnetism are antagonistic quantum matter, while their intertwining has long been considered in frustrated-lattice systems1-3. In this work, we utilize scanning tunneling microscopy and muon spin resonance to discover time-reversal symmetry-breaking superconductivity in kagome metal Cs(V,Ta)3Sb5, where the Cooper pairing exhibits magnetism and is modulated by it. In the magnetic channel, we observe spontaneous internal magnetism in a full-gap superconducting state. Under perturbations of inverse magnetic fields, we detect a time-reversal asymmetrical interference of Bogoliubov quasi-particles at a circular vector. At this vector, the pairing gap spontaneously modulates, which is distinct from pair density waves occurring at a point vector and consistent with the theoretical proposal of unusual interference effect under time-reversal symmetry-breaking. The correlation between internal magnetism, Bogoliubov quasi-particles, and pairing modulation provides a chain of experimental clues for time-reversal symmetry-breaking kagome superconductivity.

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Hanbin Deng, Guowei Liu, Z. Guguchia, Tianyu Yang, Jinjin Liu, Zhiwei Wang, Yaofeng Xie, Sen Shao, Haiyang Ma, William Liège, Frédéric Bourdarot, Xiao-Yu Yan, Hailang Qin, C. Mielke III, R. Khasanov, H. Luetkens, Xianxin Wu, Guoqing Chang, Jianpeng Liu, Morten Holm Christensen, Andreas Kreisel, Brian Møller Andersen, Wen Huang, Yue Zhao, Philippe Bourges, Yugui Yao, Pengcheng Dai, Jia-Xin Yin. 2024-08-06. Evidence chain for time-reversal symmetry-breaking kagome superconductivity. https://doi.org/10.1038/s41563-024-01995-w

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