Magneto-transport Effects in Topological Insulator Bi2Se3 Nanoribbons
Abstract
Magneto-resistance (MR) of Bi2Se3 nanoribbons is studied over a broad range of temperature (T=300K-2K) and under various magnetic field (B) orientations. The MR is strongly anisotropic with the perpendicular MR much larger than the longitudinal and transverse MRs. The perpendicular MR exhibits quadratic B-dependence in low fields and becomes linear at high B. However, when T increases, the perpendicular MR becomes linear over the whole magnetic field range (0-9T) up to room temperature. This unusual linear MR is discussed in the context of the linear quantum MR of the topological surface-states. We also observe the boundary-scattering effect in MR at low temperatures, which indicates that the out-of-plane Fermi momentum is much smaller the in-plane Fermi momentum, excluding the simple three-dimensional Fermi surface picture.