Electron behavior in topological insulator based P-N overlayer   interfaces
  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. 
L. A. Wray, M. Neupane, S.-Y. Xu, Y.-Q. Xia, A. V. Fedorov, H. Lin, S.   Basak, A. Bansil, Y. S. Hor, R. J. Cava, and M. Z. ...
cond-mat.mtrl-sci