Nontrivial surface state transport in Bi_2Se_3 topological insulator nanoribbons

摘要

Topological insulator nanostructures have the larger surface-to-volume ratios than the bulk materials, which enhances the surface state contribution to the electrical transport. Here, we report on the single-crystalline Bi_2Se_3 narrow nanoribbons synthesized by the chemical vapor deposition method. The surface state induced Aharonov-Bohm effect was observed in the parallel magnetic field. The weak antilocalization (WAL) at various temperatures can be well fitted by the ID localization theory, and the fitting coherence length is larger than the cross section size of the nanoribbon. The amplitude of WAL after subtracting the bulk background is only dependent on the vertical component of the magnetic field at various angles, revealing the surface nature of WAL. All these signatures indicate the nontrivial surface state transport in our Bi_2Se_3 narrow nanoribbons.