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arXiv · 2401.10424

Nanoscale Conducting and Insulating Domains on YbB$_6$

Aaron Coe·Zhi-Huai Zhu·Yang He·Dae-Jeong Kim·Zachary Fisk·Jason Hoffman·Jennifer Hoffman
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Abstract

YbB$_6$ is a predicted topological insulator, with experimental evidence for conducting surface states of yet-unproven origin. However, its lack of a natural cleavage plane, and resultant surface-dependent polarity, has obscured its study. We use scanning tunneling microscopy to image the cleaved surface of YbB$_6$, exhibiting several coexisting terminations with distinct atomic structures. Our spectroscopic measurements show band-bending between the terminations, resulting in both conducting and fully-gapped regions. In the conductive regions, we observe spectral peaks that are suggestive of van Hove singularities arising from Rashba spin-split quantum well states. The insulating regions rule out the possibility that YbB$_6$ is a strong topological insulator, while the spin-polarized conducting regions suggest possible utility for spintronic devices.

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Aaron Coe, Zhi-Huai Zhu, Yang He, Dae-Jeong Kim, Zachary Fisk, Jason Hoffman, Jennifer Hoffman. 2024-01-18. Nanoscale Conducting and Insulating Domains on YbB$_6$. https://doi.org/10.1103/1cft-d9np

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