Catalyst-free growth of millimeter-long topological insulator Bi₂Se₃ nanoribbons and the observation of the π-Berry phase.

Fang, L; Jia, Y; Miller, D J; Latimer, M L; Xiao, Z L; Welp, U; Crabtree, G W; Kwok, W-K · Nano Lett · 2012

basic_science · Level V

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Abstract

We report the growth of single-crystalline Bi(2)Se(3) nanoribbons with lengths up to several millimeters via a catalyst-free physical vapor deposition method. Scanning transmission electron microscopy analysis reveals that the nanoribbons grow along the (112̅0) direction. We obtain a detailed characterization of the electronic structure of the Bi(2)Se(3) nanoribbons from measurements of Shubnikov-de Haas (SdH) quantum oscillations. Angular dependent magneto-transport measurements reveal a dominant two-dimensional contribution originating from surface states. The catalyst-free synthesis yields high-purity nanocrystals enabling the observation of a large number of SdH oscillation periods and allowing for an accurate determination of the π-Berry phase, one of the key features of Dirac fermions in topological insulators. The long-length nanoribbons open the possibility for fabricating multiple nanoelectronic devices on a single nanoribbon.