Angle-resolved Photoemission Spectroscopy Study on the Surface States of the Correlated Topological Insulator YbB6

Abstract

We report the electronic structure of YbB6, a recently predicted moderately correlated topological insulator, measured by angle-resolved photoemission spectroscopy. We directly observed linearly dispersive bands around the time-reversal invariant momenta Γ and X with negligible kz dependence, consistent with odd number of surface states crossing the Fermi level in a Z2 topological insulator. Circular dichroism photoemission spectra suggest that these in-gap states possess chirality of orbital angular momentum, which is related to the chiral spin texture, further indicative of their topological nature. The observed insulating gap of YbB6 is about 100 meV, larger than that reported by theoretical calculations. Our results present strong evidence that YbB6 is a correlated topological insulator and provide a foundation for further studies of this promising material.

5 pages, 4 figures

References in corpus (7)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Correlated Topological Insulators with Mixed Valence
• Emergent quantum confinement at topological insulator surfaces
• Spin Polarization of Photoelectrons from Topological Insulators
• Circular dichroism in angle-resolved photoemission spectroscopy of topological insulators
• Surface vs bulk electronic structures of a moderately correlated topological insulator YbB6 revealed by ARPES

Cited by in corpus (6)

• Surface Theory of a Family of Topological Kondo Insulators
• Two distinct topological phases in the mixed valence compound YbB6 and its differences from SmB6
• ARPES insights on the metallic states of YbB6(001): E(k) dispersion, temporal changes and spatial variation
• Pressure-Driven Topological Phase Transition in the Yb Chalcogenides YbO and YbS
• Interacting topological phases in thin films of topological mirror Kondo insulators
• Nanoscale Conducting and Insulating Domains on YbB${}_6$