Abstract:
The newly discovered kagome superconductors AV3Sb5 (A=K, Rb, Cs) represent a promising platform for investigating the interplay between band topology, electronic order, and lattice geometry [1, 2]. Despite extensive research efforts on this system, the nature of the superconducting ground state remains elusive and a consensus on the electron pairing symmetry has not been achieved so far. In this talk, I will report our ultrahigh resolution and low-temperature angle-resolved photoemission spectroscopy (ARPES) studies on two exemplary CsV3Sb5-derived kagome superconductors — Cs(V0.93Nb0.07)3Sb5 with the appearance of charge order and Cs(V0.86Ta0.14)3Sb5 without charge order in the normal state [3]. Additionally, I will present our studies of electronic kinks in the band structure [4] and temperature-dependent muon spin relaxation rate, and discuss the possible pairing mechanisms for these kagome superconductors. Overall, our findings contribute to a better understanding of the nature of superconductivity and its intertwined orders in kagome quantum materials.

References:
[1] Neupert, T. et al., Nature Physics 18, 137 (2021).
[2] Yin et al., Nature 612, 647-657 (2022).
[3] Zhong, Y. et al., Nature, in press, arXiv:2303.00875.
[4] Zhong. Y. et al., Nat. Commun., in press, arXiv:2207.02407.

Zoom URL is available after registration at https://forms.gle/WmdX8BrFA7xhjkK2A