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Related papers: Diffusion at the Surface of Topological Insulators

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We investigate the spin conductivity of topological insulators taking into account both the surface and quasi-two-dimensional bulk states. We apply a low-energy expansion of the Hamiltonian up to the third order in momentum and take into…

Mesoscale and Nanoscale Physics · Physics 2019-01-30 R. S. Akzyanov , A. L. Rakhmanov

The topological properties of materials are, until now, associated with the features of their crystalline structure, although translational symmetry is not an explicit requirement of the topological phases. Recent studies of hopping models…

In an ideal bulk topological-insulator (TI) conducting surface states protected by time reversal symmetry enfold an insulating crystal. However, the archetypical TI, Bi2Se3, is actually never insulating; it is in fact a relatively good…

Mesoscale and Nanoscale Physics · Physics 2014-03-07 E. Lahoud , E. Maniv , M. Petrushevsky , M. Naamneh , A. Ribak , S. Wiedmann , L. Petaccia , K. B. Chashka , Y. Dagan , A. Kanigel

Hexagonal warping provides an anisotropy to the dispersion curves of the helical Dirac fermions that exist at the surface of a topological insulator. A sub-dominant quadratic in momentum term leads to an asymmetry between conduction and…

Mesoscale and Nanoscale Physics · Physics 2014-01-21 J. P. F. LeBlanc , J. P. Carbotte

Topological insulating phases are usually found in periodic lattices stemming from collective resonant effects, and it may thus be expected that similar features may be prohibited in thermal diffusion, given its purely dissipative and…

Applied Physics · Physics 2021-07-16 Guoqiang Xu , Yihao Yang , Xue Zhou , Hongsheng Chen , Andrea Alu , Cheng-Wei Qiu

We present a theoretical approach to describe the 2D transport properties of the surfaces of three dimensional topological insulators (3DTIs) including disorder and phonon scattering effects. The method that we present is able to take into…

Mesoscale and Nanoscale Physics · Physics 2013-01-01 Qiuzi Li , E. Rossi , S. Das Sarma

We construct a theory of charge transport by the surface states of topological insulators in three dimensions. The focus is on the experimentally relevant case when the electron doping is such that the Fermi energy $\epsilon_F$ and…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Dimitrie Culcer , E. H. Hwang , Tudor D. Stanescu , S. Das Sarma

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

Topological insulators (TIs) are predicted to be composed of an insulating bulk state along with conducting channels on the boundary of the material. In Bi2Se3, however, the Fermi level naturally resides in the conduction band due to…

Materials Science · Physics 2011-08-03 Matthew Brahlek , Yong Seung Kim , Namrata Bansal , Eliav Edrey , Seongshik Oh

It is well established that topological insulators sustain Dirac fermion surface states as a consequence of band inversion in the bulk. These states have a helical spin polarization and a linear dispersion with large Fermi velocity. In this…

Topological insulators are solid state systems of independent electrons for which the Fermi level lies in a mobility gap, but the Fermi projection is nevertheless topologically non-trivial, namely it cannot be deformed into that of a normal…

Mathematical Physics · Physics 2016-10-27 Hermann Schulz-Baldes

Surfaces of topological insulators host a new class of states with Dirac dispersion and helical spin texture. Potential quantum computing and spintronic applications using these states require manipulation of their electronic properties at…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 Haim Beidenkopf , Pedram Roushan , Jungpil Seo , Lindsay Gorman , Ilya Drozdov , Yew San Hor , R. J. Cava , Ali Yazdani

Transport due to spin-helical massless Dirac fermion surface state is of paramount importance to realize various new physical phenomena in topological insulators, ranging from quantum anomalous Hall effect to Majorana fermions. However, one…

Mesoscale and Nanoscale Physics · Physics 2014-02-13 Luis A. Jauregui , Michael T. Pettes , Leonid P. Rokhinson , Li Shi , Yong P. Chen

The energy-momentum relationship of electrons on the surface of an ideal "Hydrogen-Atom" Topological Insulator forms a cone - a Dirac cone, which, when warped and distorted (no longer described by the Dirac equation), can lead to unusual…

Mesoscale and Nanoscale Physics · Physics 2009-12-31 M. Z. Hasan , H. Lin , A. Bansil

Magnetotransport measurements are a popular way of characterizing the electronic structure of topological materials and often the resulting datasets cannot be described by the well-known Drude model due to large, non-parabolic…

Mesoscale and Nanoscale Physics · Physics 2019-10-23 J. C. de Boer , D. P. Leusink , A. Brinkman

The nature of Fermi surface defines the physical properties of conductors and many physical phenomena can be traced to its shape. Although the recent discovery of a current-dependent nonlinear magnetoresistance in spin-polarized…

We investigate the effects of magnetic and nonmagnetic impurities on the two-dimensional surface states of three-dimensional topological insulators (TIs). Modeling weak and strong TIs using a generic four-band Hamiltonian, which allows for…

Mesoscale and Nanoscale Physics · Physics 2016-02-26 Andreas Pieper , Holger Fehske

Three dimensional (3D) topological insulators are quantum materials with a spin-orbit induced bulk insulating gap that exhibit quantum-Hall-like phenomena in the absence of applied magnetic fields. The proposed applications of topological…

Mesoscale and Nanoscale Physics · Physics 2009-07-20 Y. Xia , D. Qian , D. Hsieh , R. Shankar , H. Lin , A. Bansil , A. V. Fedorov , D. Grauer , Y. S. Hor , R. J. Cava , M. Z. Hasan

Despite the broadband response, limited optical absorption at a particular wavelength hinders the development of optoelectronics based on Dirac fermions. Heterostructures of graphene and various semiconductors have been explored for this…

Combining the ability to prepare high-quality, intrinsic Bi$_2$Te$_3$ topological insulator thin films of low carrier density with in-situ protective capping, we demonstrate a pronounced, gate-tunable change in transport properties of…

Mesoscale and Nanoscale Physics · Physics 2016-07-04 Prosper Ngabonziza , Martin P. Stehno , Hiroaki Myoren , Viola A. Neumann , Gertjan Koster , Alexander Brinkman