The Interplay of Topological Surface and Bulk Electronic States in Bi2Se3

TL;DR

This study combines STM measurements and electronic structure calculations to explore the coexistence of topological surface states and bulk-like states in Bi2Se3, revealing their interaction and implications for quantum interference.

Contribution

It provides new insights into the coexistence and interaction of surface and bulk states in Bi2Se3 through combined experimental and theoretical analysis.

Findings

Presence of background states alongside Dirac cone

Bulk-like states with surface amplitude identified

Evidence of quantum interference between states

Abstract

In this Letter we present scanning tunneling microscopy density-of-states measurements and electronic structure calculations of the topological insulator Bi2Se3. The measurements show significant background states in addition to the expected Dirac cone. Density functional calculations using a slab model and analysis of the partial density-of-states show that the background is consistent with bulk-like states with small amplitudes at the surface. The topological surface states coexist with bulk-like states in the valence band, appearing as a shoulder in the projected band structure. These results strongly support the picture suggested by recent scattering experiments of the quantum interference of topological and bulk-like surface states.