Surface States Transport in Nanowires of Topological Insulator Bi0.83Sb0.17

Abstract

We have investigated the transport properties of topological insulator based on single-crystal Bi0.83Sb0.17 nanowires. The single-crystal nanowire samples in the diameter range 75 nm – 1.1 μm were prepared by the high frequency liquid phase casting in a glass capillary using an improved Ulitovsky technique; they were cylindrical single-crystals with (1011) orientation along the wire axis. The samples resistance increases with decreasing temperature, but at low temperatures decrease in the resistance is observed. This effect is a clear manifestation of the presence on the surface of topological insulators highly conductive zone. The Arrhenius plot of resistance R in samples with diameter d=1.1 µm and d=75 nm indicates a thermal activation behavior with an activation gap ΔE= 21 and 45 meV, respectively, which proves the presence of the quantum size effect in these samples. We found that in the range of diameter 1100 nm - 75 nm when the diameter decreases the energy gap is growing as 1/d. We have investigated magnetoresistance of Bi0.83Sb0.17 nanowires at various magnetic field orientations. From the temperature dependences of Shubnikov de Haas oscillation amplitude for different orientation of magnetic field we have calculated the cyclotron mass mc and Dingle temperature TD. For the first time the Aharonov-Bohm oscillations in Bi0.83Sb0.17 100 nm nanowire were observed.