Quantum electrical transport properties of topological insulator Bi2Te3 nanowires

• We investigated the quantum phase-coherent transport properties of topological insulator nanowires of Bi2Te3.
• Applied with an axial magnetic field, Aharonov–Bohm oscillations were observed, which is consistent with the quasi-ballistic limit.
• In a perpendicular magnetic field, negative magnetoconductance due to the weak antilocalization is observed.
• Bi2Te3 nanowires are capable of highly coherent electrical conduction through the topological surface states.

We investigate the quantum transport properties of surface electrons on a topological insulator Bi2Te3 nanowire in a magnetotransport study. Although the nanowires are synthesized by using a relatively coarse method of electrochemical deposition, clear Aharonov–Bohm oscillations of phases 0 and π are observed, owing to the highly coherent surface electron channel. The oscillation amplitude exhibits exponential temperature dependence, suggesting that the phase coherence length Lφ is inversely proportional to the temperature, as in quasi-ballistic systems. In addition, a weak antilocalization analysis on the surface channel by using a one-dimensional localization theory, enabled by successful extraction of the surface contribution from the magnetoconductance data, is provided in support of the temperature dependence of Lφ.