Here, we demonstrate zero-angle grain boundaries (GBs) in molecular beam epitaxy (MBE)-grown Bi2Se3 (0001) films which provide electrostatic fields on the order of 108 V/m that locally charge the Dirac states, modulate the carrier density, and shift the Dirac point. This intrinsic electric field effect is similar to the surface-charge regions in conventional semiconductors. These results provide the first direct experimental evidence at the atomic scale that the Dirac states are indeed robust against extended structural defects and are tunable by electric fields.
Published in Physical Review Letters:
“Charging Dirac States at Antiphase Domain Boundaries in the Three-Dimensional Topological Insulator Bi2Se3“, Y. Liu, Y. Y. Li, D. Gilks, V. K. Lazarov, M. Weinert, and L. Li, Phys. Rev. Lett. 110, 186804 (2013).
- Work featured as the cover image of Physical Review Letters (see attached image)