Low-carrier-concentration crystals of the topological insulator Bi2Te2Se

Comparison of Sn-doped and nonstoichiometric vertical-Bridgman-grown crystals of the topological insulator Bi2Te2Se

Quantum oscillations of the topological surface states in low carrier concentration crystals of Bi2−xSbxTe3−ySey

We report a high-field magnetotransport study on selected low-carrier crystals of the topological insulator Bi2−xSbxTe3−ySey. Monochromatic Shubnikov de Haas (SdH) oscillations are observed at 4.2 K and their twodimensional nature is confirmed by tilting the magnetic field with respect to the sample surface. With help of Lifshitz-Kosevich theory, important transport parameters of the surface st...

Ultra-low carrier concentration and surface-dominant transport in antimony-doped Bi₂Se₃ topological insulator nanoribbons.

A topological insulator is the state of quantum matter possessing gapless spin-locking surface states across the bulk band gap, which has created new opportunities from novel electronics to energy conversion. However, the large concentration of bulk residual carriers has been a major challenge for revealing the property of the topological surface state by electron transport measurements. Here w...

Intrinsic Topological Insulator Bi1.5Sb0.5Te3-xSex Thin Crystals

The quaternary topological insulator (Bi,Sb)2(Te,Se)3 has demonstrated topological surface states with an insulating bulk. Scientists have identified an optimized composition of Bi(1.5)Sb(0.5)Te(1.7)Se(1.3) with the highest resistivity reported. But the physics that drive to this composition remains unclear. Here we report the crystal structure and the magneto-transport properties of Bi(1.5)Sb(...

Large bulk resistivity and surface quantum oscillations in the topological insulator Bi2Te2Se

Topological insulators are predicted to present interesting surface transport phenomena but their experimental studies have been hindered by a metallic bulk conduction that overwhelms the surface transport. We show that the topological insulator Bi2Te2Se presents a high resistivity exceeding 1 cm and a variable-range hopping behavior, and yet presents Shubnikov-de Haas oscillations coming from ...