Nanoscale Conducting and Insulating Domains on YbB${}_6$

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.

arXiv commentSubmitted to Physical Review Letters

References in corpus (34)

• Topological Insulators in Three Dimensions
• Topological Insulators with Inversion Symmetry
• Topological Kondo Insulators
• Surface electronic structure of the topological Kondo insulator candidate correlated electron system SmB6
• Low-temperature surface conduction in the Kondo insulator SmB${}_6$
• Topological surface state in the Kondo Insulator Samarium Hexaboride
• Quantum oscillations in Kondo Insulator SmB${}_6$
• Robust Surface Hall Effect and Nonlocal Transport in SmB6: Indication for an Ideal Topological Insulator
• Observation of in-gap surface states in the Kondo insulator SmB6 by photoemission
• A theory of Topological Kondo Insulators
• Direct observation of the spin texture in strongly correlated SmB6 as evidence of the topological Kondo insulator
• Surface and Bulk Electronic Structure of the Strongly Correlated System SmB${}_6$ and Implications for a Topological Kondo Insulator
• Topological Crystalline Kondo Insulator in Mixed Valence Ytterbium Borides
• Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6
• Polarity-driven surface metallicity in SmB${}_6$
• Tuning bulk and surface conduction in topological Kondo insulator SmB6
• Hybridization gap and Fano resonance in SmB${}_6$
• Quantum Oscillations of Electrical Resistivity in an Insulator
• Emergence of a coherent in-gap state in SmB6 Kondo insulator revealed by scanning tunneling spectroscopy
• One-dimensional edge state transport in a topological Kondo insulator
• Correlation between bulk thermodynamic measurements and the low temperature resistance plateau in SmB6
• Kondo hybridisation and the origin of metallic states at the (001) surface of SmB6
• The importance of Charge Fluctuations for the Topological Phase in SmB${}_6$
• Imaging emergent heavy Dirac fermions of a topological Kondo insulator
• Electronic Liquid Crystalline Phases in a Spin-Orbit Coupled Two-Dimensional Electron Gas
• Non-Kondo-like Electronic Structure in the Correlated Rare-Earth Hexaboride YbB${}_6$
• Electronic structure of YbB${}_6$: Is it a Topological Insulator or not?
• Angle-resolved Photoemission Spectroscopy Study on the Surface States of the Correlated Topological Insulator YbB6
• Poor electronic screening in lightly doped Mott insulators observed with scanning tunneling microscopy
• Consistency between ARPES and STM measurements on SmB${}_6$
• Two distinct topological phases in the mixed valence compound YbB6 and its differences from SmB6
• Atomic and Electronic Structure of a Rashba $p$-$n$ Junction at the BiTeI Surface
• Comparative study of rare earth hexaborides using high resolution angle-resolved photoemission
• ARPES insights on the metallic states of YbB6(001): E(k) dispersion, temporal changes and spatial variation