Large Bandgap Observed on the Surfaces Of EuZn₂As₂ Single Crystals

Author(s)

• Dejia Kong
• Siavash Karbasizadeh
• Ganesh Narasimha
• Paras Regmi
• Chenggang Tao
• Chenggang Tao
• Sai Mu, University of South CarolinaFollow
• Rama Vasudevan
• Ian Harrison
• Rongying Jin
• Zheng Gai

Document Type

Article

Abstract

EuZn₂As₂ (M = Zn, Cd, In, Sn etc.) is an excellent material system for studying magnetism-tuned topological properties. However, discrepancies exist between experimental data and theoretical calculations regarding the bulk and surface bandgaps. In this work, cleaved EuZn₂As₂ crystals are studied using scanning tunneling microscopy/spectroscopy and density functional theory calculations. Triangular-shaped defect-induced modifications in the local density of states help distinguish between Eu-terminated and AsZn-terminated surfaces. While large bandgaps ( ~1.5 eV at 77 K) are observed on both pristine surfaces, the bandgap size is found to be highly sensitive to local heterogeneity, tending to decrease. By combining experimental observations with theoretical simulations, we conclude that the reduced bandgap in heterogeneous regions arises from Zn vacancies and/or substitution by As atoms, both impacting greater in the Eu surface electronic properties than those in the AsZn surface. This demonstrates the intimate relationship between the electronic structure and magnetism in EuZn₂As₂.

Digital Object Identifier (DOI)

https://doi.org/10.1038/s42005-025-02190-2

Publication Info

Published in Communications Physics, Volume 8, 2025.

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APA Citation

Kong, D., Karbasizadeh, S., Narasimha, G., Regmi, P., Tao, C., Mu, S., Vasudevan, R., Harrison, I., Jin, R., & Gai, Z. (2025). Large bandgap observed on the surfaces of EuZn2As2 single crystals. Communications Physics, 8.https://doi.org/10.1038/s42005-025-02190-2