Novel states of matter arise in quantum materials due to strong interactions among electrons. A nematic phase breaks the point group symmetry of the crystal lattice and is known to emerge in correlated materials. Here we report the observation of an intra-unit-cell nematic order and signatures of Pomeranchuk instability in the Kagome metal ScV6Sn6. Using scanning tunneling microscopy and spectroscopy, we reveal a stripe-like nematic order breaking the crystal rotational symmetry within the Kagome lattice itself. Moreover, we identify a set of van Hove singularities adhering to the Kagome layer electrons, which appear along one direction of the Brillouin zone while being annihilated along other high-symmetry directions, revealing a rotational symmetry breaking. Via detailed spectroscopic maps, we further observe an elliptical deformation of Fermi surface, which provides direct evidence for an electronically mediated nematic order. Our work not only bridges the gap between electronic nematicity and Kagome physics, but also sheds light on the potential mechanism for realizing symmetry-broken phases in correlated electron systems.
@article{arxiv.2406.13702,
title = {Van-Hove annihilation and nematic instability on a Kagome lattice},
author = {Yu-Xiao Jiang and Sen Shao and Wei Xia and M. Michael Denner and Julian Ingham and Md Shafayat Hossain and Qingzheng Qiu and Xiquan Zheng and Hongyu Chen and Zi-Jia Cheng and Xian P. Yang and Byunghoon Kim and Jia-Xin Yin and Songbo Zhang and Maksim Litskevich and Qi Zhang and Tyler A. Cochran and Yingying Peng and Guoqing Chang and Yanfeng Guo and Ronny Thomale and Titus Neupert and M. Zahid Hasan},
journal= {arXiv preprint arXiv:2406.13702},
year = {2024}
}