Abstract

The V-based kagome metal CsV3Sb5 hosts a cascade of symmetry-broken electronic phases, among which the most exotic ones are the potential loop-current phase and unconventional superconductivity. In this talk, I will show our recent studies using scanning tunneling microscopy to reveal the spectroscopic feature of these exotic states at the atomic scale. We found a coherent, C2-symmetric electron state that is stabilized by unidirectional electron-phonon coupling below 35K, suggesting a nematic state deep inside the charge density wave state [1-3]. We then focus on dopants of magnetic impurity Cr, to look for any signature of the interplay between the local moment and putative loop-current phase [4]. Finally, I will show evidence of a sign-change superconducting order parameter in Sn-doped system where a short-range charge-stripe order emerges [5].

References

[1] Liang, Z. et al., Phys. Rev. X 11, 031006 (2021).

[2] Nie, L. et al., Nature 604, 59-64 (2022).

[3] Wu, P. et al., Nature Physics 19, 1143–1149 (2023).

[4] Tu, Y. et al., arXiv: 2502. 20733.

[5] Huai, L. et al. arXiv:2509.17467; Li, H. et al., submitted.