The kagome superconductor CsV3Sb5 hosts a variety of charge density wave (CDW) phases, which play a fundamental role in the formation of other exotic electronic instabilities. However, identifying the precise structure of these CDW phases and their intricate relationships remain the subject of intense debate, due to the lack of static probes that can distinguish the CDW phases with identical spatial periodicity. Here, we unveil the competition between two coexisting 2×2×2 CDWs in CsV3Sb5 harnessing time-resolved X-ray diffraction. By analyzing the light-induced changes in the intensity of CDW superlattice peaks, we demonstrate the presence of both phases, each displaying a significantly different amount of melting upon excitation. The anomalous light-induced sharpening of peak width further shows that the phase that is more resistant to photo-excitation exhibits an increase in domain size at the expense of the other, thereby showcasing a hallmark of phase competition. Our results not only shed light on the interplay between the multiple CDW phases in CsV3Sb5, but also establish a non-equilibrium framework for comprehending complex phase relationships that are challenging to disentangle using static techniques.
@article{arxiv.2403.03169,
title = {Dynamical decoding of the competition between charge density waves in a kagome superconductor},
author = {Honglie Ning and Kyoung Hun Oh and Yifan Su and Alexander von Hoegen and Zach Porter and Andrea Capa Salinas and Quynh L Nguyen and Matthieu Chollet and Takahiro Sato and Vincent Esposito and Matthias C Hoffmann and Adam White and Cynthia Melendrez and Diling Zhu and Stephen D Wilson and Nuh Gedik},
journal= {arXiv preprint arXiv:2403.03169},
year = {2025}
}