Spectromicroscopic measurement of surface and bulk band structure interplay in a disordered topological insulator

Abstract

Topological insulators are bulk semiconductors that manifest in-gap massless Dirac surface states due to the topological bulk-boundary correspondence principle [1-3]. These surface states have been a subject of tremendous ongoing interest, due both to their intrinsic properties and to higher order emergence phenomena that can be achieved by manipulating the interface environment [4-11]. Here, angle resolved photoemission (ARPES) spectromicroscopy and supplementary scanning tunneling microscopy (STM) are performed on the model topological insulator Bi2Se3 to investigate the interplay of crystallographic inhomogeneity with the topologically ordered bulk and surface band structure. Quantitative analysis methods are developed to obtain key spectroscopic information in spite of a limited dwell time on each measured point. Band energies are found to vary on the scale of 50 meV across the sample surface, enabling single-sample measurements that are analogous to a multi-sample doping series (termed a "binning series"). Focusing separately on the surface and bulk electrons reveals a nontrivial hybridization-like interplay between fluctuations in the surface and bulk state energetics.

4 figures and 6 supplementary figures

References in corpus (6)

• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Ultrafast Optical Excitation of a Persistent Surface-State Population in the Topological Insulator Bi2Se3
• Ultrafast surface carrier dynamics in the topological insulator Bi2Te3
• Disorder enabled band structure engineering of a topological insulator surface
• Spontaneous gap generation on the surface of weakly interacting topological insulators using nonmagnetic impurities

Cited by in corpus (3)

• Origins of electronic bands in antiferromagnetic topological insulator MnBi${}_2$Te${}_4$
• Emergent vortex Majorana zero mode in iron-based superconductors
• Extracting unconventional spin texture in two dimensional topological crystalline insulator bismuthene via tuning bulk-edge interactions