English

Visualizing higher-fold topology in chiral crystals

Materials Science 2025-07-02 v2 Mesoscale and Nanoscale Physics

Abstract

Novel topological phases of matter are fruitful platforms for the discovery of unconventional electromagnetic phenomena. Higher-fold topology is one example, where the low-energy description goes beyond Standard Model analogs. Despite intensive experimental studies, conclusive evidence remains elusive for the \textit{multi-gap topological nature of higher-fold chiral fermions}. In this Letter, we leverage a combination of fine-tuned chemical engineering and photoemission spectroscopy with photon energy contrast to discover the higher-fold topology of a chiral crystal. We identify all bulk branches of a higher-fold chiral fermion for the first time, critically important for allowing us to explore unique Fermi arc surface states in multiple inter-band gaps, which exhibit an emergent ladder structure. Through designer chemical gating of the samples in combination with our measurements, we uncover an unprecedented multi-gap bulk boundary correspondence. Our demonstration of multi-gap electronic topology will propel future research on unconventional topological responses.

Keywords

Cite

@article{arxiv.2004.11365,
  title  = {Visualizing higher-fold topology in chiral crystals},
  author = {Tyler A Cochran and Ilya Belopolski and Kaustuv Manna and Mohammad Yahyavi and Yiyuan Liu and Daniel S. Sanchez and Zi-Jia Cheng and Xian P. Yang and Daniel Multer and Jia-Xin Yin and Horst Borrmann and Alla Chikina and Jonas A. Krieger and Jaime Sánchez-Barriga and Patrick Le Fèvre and François Bertran and Vladimir N. Strocov and Jonathan D. Denlinger and Tay-Rong Chang and Shuang Jia and Claudia Felser and Hsin Lin and Guoqing Chang and M. Zahid Hasan},
  journal= {arXiv preprint arXiv:2004.11365},
  year   = {2025}
}

Comments

Updated to accepted version of main article and supplemental information

R2 v1 2026-06-23T15:03:40.912Z