The kagome superconductor family AV3Sb5 (A=Cs, K, Rb) emerged as an exciting platform to study exotic Fermi surface instabilities. Here we use spectroscopic-imaging scanning tunneling microscopy (SI-STM) and angle-resolved photoemission spectroscopy (ARPES) to reveal how the surprising cascade of higher and lower-dimensional density waves in CsV3Sb5 is intimately tied to a set of small reconstructed Fermi pockets. ARPES measurements visualize the formation of these pockets generated by a 3D charge density wave transition. The pockets are connected by dispersive q* wave vectors observed in Fourier transforms of STM differential conductance maps. As the additional 1D charge order emerges at a lower temperature, q* wave vectors become substantially renormalized, signaling further reconstruction of the Fermi pockets. Remarkably, in the superconducting state, the superconducting gap modulations give rise to an in-plane Cooper pair-density-wave at the same q* wave vectors. Our work demonstrates the intrinsic origin of the charge-stripes and the pair-density-wave in CsV3Sb5 and their relationship to the Fermi pockets. These experiments uncover a unique scenario of how Fermi pockets generated by a parent charge density wave state can provide a favorable platform for the emergence of additional density waves.
@article{arxiv.2303.07254,
title = {Small Fermi pockets intertwined with charge stripes and pair density wave order in a kagome superconductor},
author = {Hong Li and Dongjin Oh and Mingu Kang and He Zhao and Brenden R Ortiz and Yuzki Oey and Shiang Fang and Zheng Ren and Chris Jozwiak and Aaron Bostwick and Eli Rotenberg and Joseph G. Checkelsky and Ziqiang Wang and Stephen D. Wilson and Riccardo Comin and Ilija Zeljkovic},
journal= {arXiv preprint arXiv:2303.07254},
year = {2023}
}