Angular-dependences of giant in-plane and interlayer magnetoresistances in Bi2Te3 bulk single crystals

Abstract

Angular-dependences of in-plane and interlayer magnetotransport properties in n-type Bi2Te3 bulk single crystals have been investigated over a broad range of temperatures and magnetic fields. Giant in-plane magnetoresistances (MR) of up to 500% and interlayer MR of up to 200% were observed, respectively. The observed MR exhibits quadratic field dependences in low fields and linear field dependences in high fields. The angular dependences of the MR represent strong anisotropy and twofold oscillations. The observed angle-dependent, giant MR might result from the strong coulomb scattering of electrons as well as impurity scattering in the bulk conduction bands of n-type Bi2Te3. The strong anisotropy of the MR may be attributable to the anisotropy of electron mobility, effective mass, and relaxation time in the Fermi surface. The observed giant anisotropic MR in n-type Bi2Te3 bulk single crystals paves the way for Bi2Te3 single crystals to be useful for practical applications in magnetoelectronic devices such as disk reading heads, anisotropic magnetic sensors, and other multifunctional electromagnetic applications.

High field (up to 140 kOe) angle dependent magneto transport of Bi2Te3 single crystals

“…Thus, the MR (%) value reduces from 440% to 150% as the temperature is increased from 5 K to 100 K. Moreover, as the field is changed from perpendicular to parallel the MR value reduces to 82% at 5 K under an applied magnetic field of 140 kOe. Further, the same reduces from 82% to 43% as the temperature is increased from 5 K to 100 K. Thus, we get a negligible value of MR in parallel component in comparison to the perpendicular component.Consequently, we can say that the MR is angular dependent [10,11,15]. Figure 5 represents the field derivative MR as a function of magnetic field.…”

Separation of electron and hole dynamics in the semimetal LaSb

“…Indeed, ARPES experiments [42] Furthermore, the isotropic two-band mode cannot account for the four-fold angle dependence of the resistivity ρ(θ), as delineated in Fig.4(b). Although the surface states of a topological material such as SmB 6 could induce a similar four-fold angular magnetoresistance [61,62], the anisotropy in Fig.4(b) shows that nearly perfect four-fold symmetry should not arise from the crystal surfaces, since the crystal's width (223.33 μm) is much larger than its thickness (138.78 μm). ARPES experiments [42] have revealed that LaSb is topologically trivial.…”

Evidence for topological surface states in metallic single crystals of Bi2Te3

“…It is also observed that the magnetoresistance in addition to being large is also linear and non-saturating. [17][18][19][20][21][22] Such large and linear magnetoresistance, which does not saturate even at high fields, was first observed in polycrystalline Bismuth and other metals by Kapitza 23,24 and this was explained by Lifshits 25 et al as due to open Fermi surfaces of the metals. However Bismuth has a small and closed Fermi surface.…”