Resonantly enhanced photoemission from topological surface states in MnBi$_6$Te$_{10}$

Abstract

The dispersion of topological surface bands in MnBi$_2$Te$_4$-based magnetic topological insulator heterostructures is strongly affected by band hybridization and is spatially inhomogeneous due to varying surface layer terminations on microscopic length scales. Here, we apply micro-focused angle-resolved photoemission spectroscopy with tunable photon energy from 18 to 30 eV to distinguish bulk valence and conduction bands from surface bands on the three surface terminations of MnBi$_6$Te$_10$. We observe a strong enhancement of photoemission intensity from the topological surface bands at the Bi O4 absorption edge, which is exploited to visualize a gapless Dirac cone on the MnBi$_2$Te$_4$-terminated surface and varying degrees of hybridization effects in the surface bands on the two distinct Bi$_2$Te$_3$-terminated surfaces.