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Related papers: Model Hamiltonian for Topological Insulators

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A two-dimensional topological insulator may arise in a centrosymmetric commensurate N\'{e}el antiferromagnet (AF), where staggered magnetization breaks both the elementary translation and time reversal, but retains their product as a…

Strongly Correlated Electrons · Physics 2017-04-05 Frédéric Bègue , Pierre Pujol , Revaz Ramazashvili

Periodic Hamiltonians on a three-dimensional (3-D) lattice with a spectral gap not only on the bulk but also on two edges at the common Fermi level are considered. By using K-theory applied for the quarter-plane Toeplitz extension, two…

Mathematical Physics · Physics 2018-10-18 Shin Hayashi

A topological insulator is classically modeled as an isotropic dielectric-magnetic with a magnetoelectric pseudoscalar $\Psi$ existing in its bulk while its surface is charge-free and current-free. An alternative model is obtained by…

Optics · Physics 2017-07-06 Akhlesh Lakhtakia , Tom G. Mackay

Topological insulators represent a novel state of matter with surface charge carriers having a massless Dirac dispersion and locked helical spin polarization. Many exciting experiments have been proposed by theory, yet, their execution have…

Materials Science · Physics 2014-10-27 Katharina Höfer , Christoph Becker , Diana Rata , Jesse Swanson , Peter Thalmeier , Liu Hao Tjeng

Spin-momentum locking, a key property of the surface states of three-dimensional topological insulators (3DTIs), provides a new avenue for spintronics applications. One consequence of spin-momentum locking is the induction of surface spin…

Mesoscale and Nanoscale Physics · Physics 2020-07-08 Ali Asgharpour , Cosimo Gorini , Sven Essert , Klaus Richter , İnanç Adagideli

The development of nanoscale solid-state devices exploiting the promising topological surface states of topological insulator materials requires careful device engineering and improved materials quality. For instance, the introduction of a…

Mesoscale and Nanoscale Physics · Physics 2021-12-21 C. Lupo , J. Andzane , D. Montemurro , T. Bauch , F. Lombardi , C. Weber , I. Rungger , S. E. de Graaf

We consider topological insulators and superconductors with discrete symmetries and clarify the relevant index theory behind the periodic table proposed by Kitaev. An effective Hamiltonian determines the analytical index, which can be…

Mathematical Physics · Physics 2017-10-05 Dan Li

In an ideal 3D topological insulator (TI), the bulk is insulating and the surface conducting due to the existence of metallic states that are localized on the surface; these are the topological surface states. Quaternary Bi-based compounds…

Notion of square-root topological insulators have been recently generalized to higher-order topological insulators. In two-dimensional square-root higher-order topological insulators, emergence of in-gap corner states are inherited from the…

Mesoscale and Nanoscale Physics · Physics 2023-02-23 Daiki Matsumoto , Tomonari Mizoguchi , Yasuhiro Hatsugai

In this paper we construct a simple, controllable, two dimensional model based on a topological band insulator. It has many attractive properties. (1) We obtain spin-charge separated solitons that are associated with $\pi$ fluxes. (2) It…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Ying Ran , Ashvin Vishwanath , Dung-Hai Lee

In this work, we use charge extraction via organic overlayer deposition to lower the chemical potential of topological insulator Bi2Se3 thin films into the intrinsic (bulk-insulating) regime. We demonstrate the tuning and stabilization of…

Mesoscale and Nanoscale Physics · Physics 2016-06-01 Liang Wu , R. M. Ireland , M. Salehi , B. Cheng , N. Koirala , S. Oh , H. E. Katz , N. P. Armitage

The electrodynamics of topological insulators (TIs) is described by modified Maxwell's equations, which contain additional terms that couple an electric field to a magnetization and a magnetic field to a polarization of the medium, such…

Strongly Correlated Electrons · Physics 2017-05-16 V. Dziom , A. Shuvaev , A. Pimenov , G. V. Astakhov , C. Ames , K. Bendias , J. Böttcher , G. Tkachov , E. M. Hankiewicz , C. Brüne , H Buhmann , L. W. Molenkamp

Three dimensional topological insulators are bulk insulators with $\mathbf{Z}_2$ topological electronic order that gives rise to conducting light-like surface states. These surface electrons are exceptionally resistant to localization by…

Mesoscale and Nanoscale Physics · Physics 2017-03-07 Yishuai Xu , Janet Chiu , Lin Miao , Haowei He , Zhanybek Alpichshev , A. Kapitulnik , Rudro R. Biswas , L. Andrew Wray

We study second-order topological insulators and semimetals characterized by chiral symmetry. We investigate topological phase transitions of a model for construction of the two-dimensional second-order topological insulators protected only…

Mesoscale and Nanoscale Physics · Physics 2019-12-06 Ryo Okugawa , Shin Hayashi , Takeshi Nakanishi

We introduce new three-dimensional topological phases of two-band models using the Pontryagin-Thom construction. In symmetry class A these are the infinitely many Hopf-Chern topological insulators, which are hybrids of layered Chern…

Mesoscale and Nanoscale Physics · Physics 2016-07-27 Ricardo Kennedy

The possibility of realizing topological insulators by spontaneous formation of electronic superstructure is theoretically investigated in a minimal two-orbital model including both the spin-orbit coupling and electron correlations on a…

Strongly Correlated Electrons · Physics 2016-06-21 Yusuke Sugita , Yukitoshi Motome

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…

Materials Science · Physics 2015-05-28 Zhi Ren , A. A. Taskin , Satoshi Sasaki , Kouji Segawa , Yoichi Ando

In this manuscript, we study the interplay between symmetry and topology with a focus on the $Z_2$ topological index of 2D/3D topological insulators and high-order topological insulators. We show that in the presence of either a…

Mesoscale and Nanoscale Physics · Physics 2020-08-06 Heqiu Li , Kai Sun

We present a systematic derivation of effective lattice spin Hamiltonians derived from a rotationally invariant multi-orbital Hubbard model including a term ensuring Hund's rule coupling. The Hamiltonians are derived down-folding the…

Mesoscale and Nanoscale Physics · Physics 2020-01-29 Markus Hoffmann , Stefan Blügel

The system of spinless fermions on a hexagonal lattice is studied . We have considered tight-binding model with the hopping integrals between the nearest-neighbor and next-nearest-neighbor lattice sites, that depend on the direction of the…

Strongly Correlated Electrons · Physics 2017-04-27 Igor N. Karnaukhov