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Related papers: Ambipolar Electric Field Effect in Metallic Bi2Se3

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Topological insulators are insulating in the bulk but possess metallic surface states protected by time-reversal symmetry. Here, we report a detailed electronic transport study in high quality Bi2Se3 topological insulator thin films…

A Bi2Se3 topological insulator field effect transistor is investigated by using ionic liquid as an electric double layer gating material, leading to a conductance modulation of 365% at room temperature. We discuss the role of charged…

We demonstrate the ability to reduce the carrier concentration of thin films of the topological insulator (TI) Bi2Se3 by utilizing a novel approach, namely non-volatile electrostatic gating via corona charging of electret polymers.…

Mesoscale and Nanoscale Physics · Physics 2018-04-11 R. M. Ireland , Liang Wu , M. Salehi , S. Oh , N. P. Armitage , H. E. Katz

(Bi$_{1-x}$Sb$_x$)$_2$Te$_3$ alloys are non-degenerate topological insulators (TIs) whose Dirac point (DP) can be tuned within the bulk bandgap by varying the composition, effectively reducing bulk conduction while allowing surface carrier…

An important challenge in the field of topological materials is to carefully disentangle the electronic transport contribution of the topological surface states from that of the bulk. For Bi$_2$Te$_3$ topological insulator samples, bulk…

Materials Science · Physics 2018-05-02 Prosper Ngabonziza , Yi Wang , Alexander Brinkman

The Dirac-like surface states of the topological insulators (TIs) are protected by time reversal symmetry (TRS) and exhibit a host of novel properties. Introducing magnetism into TI, which breaks the TRS, is expected to create exotic…

We report x-ray diffraction, electrical resistivity, and magnetoresistance measurements on Bi2Se3 under high pressure and low temperature conditions. Pressure induces profound changes in both the room temperature value of the electrical…

Materials Science · Physics 2015-06-03 J. J. Hamlin , J. R. Jeffries , N. P. Butch , P. Syers , D. A. Zocco , S. T. Weir , Y. K. Vohra , J. Paglione , M. B. Maple

Electrical field control of the carrier density of topological insulators (TI) has greatly expanded the possible practical use of these materials. However, the combination of low temperature local probe studies and a gate tunable TI device…

Mesoscale and Nanoscale Physics · Physics 2013-04-15 Tong Zhang , Niv Levy , Jeonghoon Ha , Young Kuk , Joseph A. Stroscio

Topological insulators (TI) are a phase of matter that host unusual metallic states on their surfaces. Unlike the states that exist on the surface of conventional materials, these so-called topological surfaces states (TSS) are protected…

Achieving true bulk insulating behavior in Bi$_2$Se$_3$, the archetypal topological insulator with a simplistic one-band electronic structure and sizable band gap, has been prohibited by a well-known self-doping effect caused by selenium…

Materials Science · Physics 2017-01-19 Paul Syers , Johnpierre Paglione

We report on electronic transport measurements of dual-gated nano-devices of the low-carrier density topological insulator Bi1.5Sb0.5Te1.7Se1.3. In all devices the upper and lower surface states are independently tunable to the Dirac point…

The surface states of a 3D topological insulator (TI) exhibit topological protection against backscattering. However, the contribution of bulk electrons to the transport data is an impediment to the topological protection of surface. We…

Strongly Correlated Electrons · Physics 2016-12-02 R. K. Gopal , Sourabh Singh , Arpita Mandal , Jit Sarkar , Chiranjib Mitra

We consider the transport properties of topological insulators surface states in the presence of uncorrelated point-like disorder, both in the classical and quantum regimes. The transport properties of those two-dimensional surface states…

Mesoscale and Nanoscale Physics · Physics 2012-05-24 Pierre Adroguer , David Carpentier , Jérôme Cayssol , Edmond Orignac

Surface states of topological insulators (TIs) have been playing the central role in the majority of outstanding investigations in low-dimensional electron systems for more than 10 years. TIs based on high-quality strained HgTe films…

Mesoscale and Nanoscale Physics · Physics 2019-05-15 M. L. Savchenko , D. A. Kozlov , N. N. Vasilev , Z. D. Kvon , N. N. Mikhailov , S. A. Dvoretsky , A. V. Kolesnikov

Three-dimensional (3D) topological insulators (TI) are novel quantum materials with insulating bulk and topologically protected metallic surfaces with Dirac-like band structure. The spin-helical Dirac surface states are expected to host…

Three-dimensional (3-D) topological insulators (TI) are characterized by the presence of metallic surface states and a bulk band gap. Recently theoretical and experimental studies have shown an induced gap in the surface state bands of TI…

Mesoscale and Nanoscale Physics · Physics 2012-12-21 Jiwon Chang , Leonard F. Register , Sanjay K. Banerjee

Spin-based electronics in topological insulators (TIs) is favored by the long spin coherence1,2 and consequently fault-tolerant information storage. Magnetically doped TIs are ferromagnetic up to 13 K,3 well below any practical operating…

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…

Materials Science · Physics 2019-08-13 Amit Jash , Kamalika Nath , T. R. Devidas , A. Bharathi , S. S. Banerjee

In ideal topological insulator (TI) films the bulk state, which is supposed to be insulating, should not provide any electric coupling between the two metallic surfaces. However, transport studies on existing TI films show that the…

Materials Science · Physics 2014-10-21 Matthew Brahlek , Nikesh Koirala , Maryam Salehi , Namrata Bansal , Seongshik Oh

By eliminating normal fabrication processes, we preserve the bulk insulating state of calcium-doped Bi2Se3 single crystals in suspended nanodevices, as indicated by the activated temperature dependence of the resistivity at low…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Peng Wei , Zhiyong Wang , Xinfei Liu , Vivek Aji , Jing Shi