Electrical Transport Properties of Bi$_{2}$Te$_{3}$ Nanotubes and Nanowires

Electrical transport properties of promising topological insulator, Bi$_{2}$Te$_{3}$ nanowires and nanotubes are measured at different temperatures and magnetic field and the results are compared with the Bi$_{2}$Se$_{3}$ thin films. The nanotube and nanowire samples are synthesized by galvanostatic electrodepositon and solution phase methods, with diameters of 70nm (ex) and 50nm (in) for nanotubes and 80$\sim $100nm for nanowires, respectively. The contact leads (Pt) are fabricated by using Focusing Ion Beam (FIB). The magnetoresistance of Bi$_{2}$Te$_{3}$ nanotubes shows linear dependence as a function of magnetic field, with a notable peak around zero field. This is different from Bi$_{2}$Se$_{3}$ thin films which show quadratic behavior, with a significant dip near zero field. The results will be discussed based on the possible weak localization effect in the nanotubes in comparison with the weak anti-localization effect in the films.