Área de investigación | Física |
Título | Consistency between ARPES and STM measurements on SmB6 |
Tipo de publicación | Artículo de revista |
Año de publicación | 2020 |
Autores | Matt, CE, Pirie, H, Soumyanarayanan, A, He, Y, Yee, MM, Chen, P, Liu, Y, Larson, DT, Paz, WS, Palacios, JJ, Hamidian, MH, Hoffman, JE |
Revista | PHYSICAL REVIEW B |
Volumen | 101 |
Número | 8 |
Type of Article | Article |
Abstract | The Kondo insulator SmB6 has emerged as a primary candidate for exotic quantum phases, due to the predicted formation of strongly correlated, low-velocity topological surface states and corresponding high Fermi-level density of states. However, measurements of the surface-state velocity in SmB6 differ by orders of magnitude, depending on the experimental technique used. Here we reconcile two techniques, scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES), by accounting for surface band bending on polar terminations. Using spatially resolved scanning tunneling spectroscopy, we measure a band shift of similar to 20 meV between full-Sm and half-Sm terminations, in qualitative agreement with our density-functional theory calculations of the surface charge density. Furthermore, we reproduce the apparent high-velocity surface states reported by ARPES by simulating their observed spectral function as an equal-weight average over the two band-shifted domains that we image by STM. Our results highlight the necessity of local measurements to address inhomogeneously terminated surfaces or fabrication techniques to achieve uniform termination for meaningful large-area surface measurements of polar crystals such as SmB6. |
DOI | 10.1103/PhysRevB.101.085142 |