Related papers: Ambipolar surface state transport in non-metallic …
While evidence of a topologically nontrivial surface state has been identified in surface-sensitive measurements of Bi2Se3, a significant experimental concern is that no signatures have been observed in bulk transport. In a search for such…
With a large band gap and a single Dirac cone responsible for the topological surface states, Bi2Se3 is widely regarded as a prototypical 3D topological insulator. Further applications of the bulk material has, however, been hindered by…
Electronic transport experiments involving the topologically protected states found at the surface of Bi2Se3 and other topological insulators require fine control over carrier density, which is challenging with existing bulk-doped material.…
We present a study of the structural and electronic properties of highly doped topological insulator Bi2Se3 single crystals synthesized by the Bridgman method. Lattice structural characterizations by X-ray diffraction, scanning tunneling…
Pure Topological Insulating materials preserve a unique electronic state comprising of bulk insulating gap and conducting surface states. Here we use bulk Bi2Se3 single crystals possessing Se vacancy defects as a prototype topological…
Topological insulators are known to their metallic surface states, a result of strong-spin-orbital coupling, that show unique surface transport phenomenon. But these surface transports are buried in presence of metallic bulk conduction. We…
We report that the ionic-liquid gating of bulk single crystals of a topological insulator can control the type of the surface carriers and even results in ambipolar transport. This was made possible by the use of a highly bulk-insulating…
We report a transport study of exfoliated few monolayer crystals of topological insulator Bi$_2$Se$_3$ in an electric field effect (EFE) geometry. By doping the bulk crystals with Ca, we are able to fabricate devices with sufficiently low…
Topological insulators possess a non-conductive bulk and present surface states, henceforth, they are electrically conductive along their boundaries. Bismuth selenide ($Bi_2Se_3$) is one of the most promising topological insulators.…
Topological insulators (TIs) constitute a new class of materials with unique properties resulting from the relativistic-like character and topological protection of their surface states. Theory predicts these to exhibit a rich variety of…
The bulk of topological insulators is relatively unexplored due to excess contribution of conduction from native defects. Here we investigate the bulk conduction in a Bi2Te3 crystal having reduced defect induced conduction. Our results…
Bi2Se3 is an important semiconductor thermoelectric material and a prototype topological insulator. Here we report observation of Shubnikov-de Hass (SdH) oscillations accompanied by quantized Hall resistances (Rxy) in highly-doped n-type…
Low-field magnetotransport measurements of topological insulators such as Bi$_2$Se$_3$ are important for revealing the nature of topological surface states by quantum corrections to the conductivity, such as weak-antilocalization. Recently,…
The newly-discovered three-dimensional strong topological insulators (STIs) exhibit topologically-protected Dirac surface states. While the STI surface state has been studied spectroscopically by e.g. photoemission and scanned probes,…
We report the effect of Sn doping on the transport properties of the topological insulator Bi_{2}Te_{2}Se studied in a series of Bi_{2-x}Sn_{x}Te_{2}Se crystals with 0 \leq x \leq 0.02. The undoped stoichiometric compound (x = 0) shows an…
Bi2Te3 is a member of a new class of materials known as topological insulators which are supposed to be insulating in the bulk and conducting on the surface. However experimental verification of the surface states has been difficult in…
In 3D topological insulators achieving a genuine bulk-insulating state is an important research topic. Recently, the material system (Bi,Sb)$_{2}$(Te,Se)$_{3}$ (BSTS) has been proposed as a topological insulator with high resistivity and a…
We present a defect-engineering strategy to optimize the transport properties of the topological insulator Bi2Se3 to show a high bulk resistivity and clear quantum oscillations. Starting with a p-type Bi2Se3 obtained by combining Cd doping…
Topological insulators (TIs) are emergent materials with unique band structure, which allow the study of quantum effect in solids, as well as contribute to high performance quantum devices. To achieve the better performance of TI, here we…
Topological insulators represent a new state of quantum matter attractive to both fundamental physics and technological applications such as spintronics and quantum information processing. In a topological insulator, the bulk energy gap is…