  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.
