Electron behavior in topological insulator based P-N overlayer interfaces

TL;DR

This study investigates electron behavior at P-N overlayer interfaces on topological insulators, revealing unique electron interactions and spectral features crucial for understanding topological material interfaces.

Contribution

It provides new experimental insights into electron dynamics and spectral properties at P-N doped topological insulator interfaces, expanding knowledge beyond previous N-N surface studies.

Findings

Unconventional Rashba-like electron interactions observed.

Larger interface potentials than previous studies.

Distinct spectral weight distribution near Dirac point.

Abstract

Topological insulators (TIs) are novel materials that manifest spin-polarized Dirac states on their surfaces or at interfaces made with conventional matter. We have measured the electron kinetics of bulk doped TI Bi$_2$Se$_3$ with angle resolved photoemission spectroscopy while depositing cathodic and anodic adatoms on the TI surfaces to add charge carriers of the opposite sign from bulk dopants. These P-N overlayer interfaces create Dirac point transport regimes and larger interface potentials than previous N-N type surface deposition studies, revealing unconventional Rashba-like and surface-bulk electron interactions, and an unusual characteristic distribution of spectral weight near the Dirac point in TI Dirac point interfaces. The electronic structures of P-N doped topological interfaces observed in these experiments are an important step towards the understanding of solid interfaces with topological materials.