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Related papers: Large Gap Topological Insulator Bi2Te3 with a Sing…

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Topological insulators are bulk semiconductors that manifest in-gap massless Dirac surface states due to the topological bulk-boundary correspondence principle [1-3]. These surface states have been a subject of tremendous ongoing interest,…

We have performed angle-resolved photoemission spectroscopy on Pb(Bi1-xSbx)2Te4, which is a member of lead-based ternary tellurides and has been theoretically proposed as a candidate for a new class of three-dimensional topological…

Mesoscale and Nanoscale Physics · Physics 2012-03-14 S. Souma , K. Eto , M. Nomura , K. Nakayama , T. Sato , T. Takahashi , Kouji Segawa , Yoichi Ando

We calculate the local density of states of two prototypical topological insulators (Bi$_2$Se$_3$ and Bi$_2$Te$_2$Se) as a function of distance from the surface within density functional theory. We find that, in the absence of disorder or…

Mesoscale and Nanoscale Physics · Physics 2015-10-08 Benjamin M. Fregoso , Sinisa Coh

Topological insulators (TIs) are a new quantum state of matter. Their surfaces and interfaces act as a topological boundary to generate massless Dirac fermions with spin-helical textures. Investigation of fermion dynamics near the Dirac…

We report thermoelectric (TE) properties of topological surface Dirac states (TSDS) in three-dimensional topological insulators (3D-TIs) purely isolated from the bulk by employing single crystal Bi$_{2-x}$Sb$_x$Te$_{3-y}$Se$_y$ films…

Topological insulators are a recently discovered class of materials with fascinating properties: While the inside of the solid is insulating, fundamental symmetry considerations require the surfaces to be metallic. The metallic surface…

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…

A two-step doping process, magnetic followed by charge or vice versa, is required to produce insulating massive surface states in topological insulators for many physics and device applications. Using first-principles calculations, we…

Materials Science · Physics 2013-12-19 Lei Shen , Minggang Zeng , Yunhao Lu , Ming Yang , Yuan Ping Feng

Aiming at the future spintronics device applications of the spin-polarized surface states in three-dimensional topological insulator, a highly insulating bulk state and a tunable Dirac cone surface state are required. Here we employ a slab…

Materials Science · Physics 2020-01-01 Takao Kosaka , Kunihiko Yamauchi , Tamio Oguchi

The topological surface states of mercury telluride (HgTe) are studied by ab initio calculations assuming different strains and surface terminations. For the Te-terminated surface, a single Dirac cone exists at the $\Gamma$ point. The Dirac…

Materials Science · Physics 2014-10-31 Shu-Chun Wu , Binghai Yan , Claudia Felser

Topological insulators (TIs) are bulk insulators with exotic 'topologically protected' surface conducting modes. It has recently been pointed out that when stacked together, interactions between surface modes can induce diverse phases…

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,…

Mesoscale and Nanoscale Physics · Physics 2012-06-05 Dohun Kim , Sungjae Cho , Nicholas P. Butch , Paul Syers , Kevin Kirshenbaum , Shaffique Adam , Johnpierre Paglione , Michael S. Fuhrer

Detailed study of the LDOS associated with the surface-state-band near a step-edge of the strong topological-insulator Bi2Te3, reveal a one-dimensional bound state that runs parallel to the stepedge and is bound to it at some characteristic…

Strongly Correlated Electrons · Physics 2013-05-29 Zhanybek Alpichshev , J. G. Analytis , J. -H. Chu , I. R. Fisher , A. Kapitulnik

Using angle-resolved photoemission spectroscopy, we report electronic structure for representative members of ternary topological insulators. We show that several members of this family, such as Bi2Se2Te, Bi2Te2Se, and GeBi2Te4, exhibit a…

A combined experimental and theoretical study of doping individual Fe atoms into Bi2Se3 is presented. It is shown through a scanning tunneling microscopy study that single Fe atoms initially located at hollow sites on top of the surface…

Topological insulators in the Bi2Se3 family have an energy gap in the bulk and a gapless surface state consisting of a single Dirac cone. Low frequency optical absorption due to the surface state is universally determined by the fine…

Materials Science · Physics 2015-03-17 Xiao Zhang , Jing Wang , Shou-Cheng Zhang

The recent theoretical prediction and experimental realization of topological insulators (TI) has generated intense interest in this new state of quantum matter. The surface states of a three-dimensional (3D) TI such as Bi_2Te_3, Bi_2Se_3…

In this Letter we present scanning tunneling microscopy density-of-states measurements and electronic structure calculations of the topological insulator Bi2Se3. The measurements show significant background states in addition to the…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 Megan Romanowich , Mal-Soon Lee , Duck-Young Chung , Jung-Hwan Song , S. D. Mahanti , Mercouri G. Kanatzidis , Stuart H. Tessmer

The observation of helical surface states in Bi-based three-dimensional topological insulators has been a challenge since their theoretical prediction. The main issue raises when the Fermi level shifts deep into the bulk conduction band due…

Mesoscale and Nanoscale Physics · Physics 2021-02-18 Shaham Jafarpisheh , An Ju , Kevin Janßen , Takashi Taniguchi , Kenji Watanabe , Christoph Stampfer , Bernd Beschoten

We have extended the search for topological insulators to the ternary tetradymite-like compounds M2X2Y (M = Bi or Sb; X and Y = S, Se or Te), which are variations of the well-known binary compounds Bi2Se3 and Bi2Te3. Our first-principles…

Materials Science · Physics 2012-05-16 H. Lin , Tanmoy Das , L. A. Wray , S. -Y. Xu , M. Z. Hasan , A. Bansil