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Related papers: Fundamental bound on topological gap

200 papers

Photonic topological insulators exhibit bulk-boundary correspondence, which requires that boundary-localized states appear at the interface formed between topologically distinct insulating materials. However, many topological photonic…

Optics · Physics 2023-11-30 Kahlil Y. Dixon , Terry A. Loring , Alexander Cerjan

The non-trivialness of a topological insulator (TI) is characterized either by a bulk topological invariant or by the existence of a protected metallic surface state. Yet, in realistic samples of finite size this non-trivialness does not…

Mesoscale and Nanoscale Physics · Physics 2013-01-08 Ken-Ichiro Imura , Mayuko Okamoto , Yukinori Yoshimura , Yositake Takane , Tomi Ohtsuki

Microwave impedance microscopy (MIM) has been utilized to directly visualize topological edge states in many quantum materials, from quantum Hall systems to topological insulators, across the GHz regime. While the microwave response for…

Mesoscale and Nanoscale Physics · Physics 2024-01-02 Taige Wang , Chen Wu , Masataka Mogi , Minoru Kawamura , Yoshinori Tokura , Zhi-Xun Shen , Yi-Zhuang You , Monica T. Allen

Considerable efforts have recently been devoted to the experimental realization of a two-dimensional Chern insulator, i.e., a system displaying a quantum anomalous Hall effect. However, existing approaches such as those based on magnetic…

Materials Science · Physics 2014-09-12 Kevin F. Garrity , David Vanderbilt

In magnetic topological insulators, the surface states can exhibit a gap due to the breaking of time-reversal symmetry. Various experiments, while suggesting the existence of the surface gap, have raised questions about its underlying…

Mesoscale and Nanoscale Physics · Physics 2024-11-20 Habib Rostami , Ali G. Moghaddam

The main result of the article is validity of the limiting absorption principle and thus absence of the singular continuous spectrum for compact quantum graphs with several infinite leads attached. The technique used involves…

Mathematical Physics · Physics 2007-05-23 Beng-Seong Ong

The possible realization of dissipationless chiral edge current in a topological insulator / magnetic insulator heterostructure is based on the condition that the magnetic proximity exchange coupling at the interface is dominated by the…

Mesoscale and Nanoscale Physics · Physics 2017-11-08 Mingda Li , Qichen Song , Weiwei Zhao , Joseph A Garlow , Te-Huan Liu , Lijun Wu , Yimei Zhu , Jagadeesh Moodera , Moses H W Chan , Gang Chen , Cui-Zu Chang

We study the influence of the antiferromagnetic order on the surface states of topological insulators. We derive an effective Hamiltonian for these states, taking into account the spatial structure of the antiferromagnetic order. We obtain…

Mesoscale and Nanoscale Physics · Physics 2024-05-14 R. S. Akzyanov , A. L. Rakhmanov

The embedding theorem of Roelcke and Dierolf for the completions of four standard uniform structures on topological groups and their quotients holds more generally for spaces of uniform measures. The natural mappings between the four spaces…

Group Theory · Mathematics 2023-06-06 Jan Pachl

Topological insulators represent a new quantum state of matter which is characterized by peculiar edge or surface states that show up due to a topological character of the bulk wave functions. This review presents a pedagogical account on…

Materials Science · Physics 2013-09-04 Yoichi Ando

Topological mapping of a large physical system on a graph, and its decomposition using universal measures is proposed. We find inherent limits to the potential for optimization of a given system and its approximate representations by…

Social and Information Networks · Computer Science 2015-02-10 Vladan Mlinar

Topological insulators embody a newly discovered state of matter characterized by conducting spin-momentum locked surface states that span the bulk band gap. So far, most of the study on topological insulator surfaces has been limited to…

Mesoscale and Nanoscale Physics · Physics 2012-06-04 L. A. Wray , Y. Xia , S. -Y. Xu , Y. S. Hor , R. J. Cava , A. Bansil , H. Lin , M. Z. Hasan

Energy gap and wave function in thin films of topological insulator is studied, based on tight--binding model. It is revealed that thickness dependence of the magnitude of energy gap is composed of damping and oscillation. The damped…

Mesoscale and Nanoscale Physics · Physics 2015-06-03 Kazuto Ebihara , Keiji Yada , Ai Yamakage , Yukio Tanaka

We study the interface between a fractional topological insulator and an ordinary insulator, both described using holography. By turning on a chemical potential we induce a finite density of matter localized at the interface. These are…

High Energy Physics - Theory · Physics 2013-05-30 Moshe Rozali

Past work has considered the analytic properties of the reflection coefficient for a metal-backed slab. The primary result established a fundamental relationship for the minimal layer thickness to bandwidth ratio achievable for an absorber.…

Optics · Physics 2023-12-18 Willie J. Padilla , Yang Deng , Omar Khatib , Vahid Tarokh

We discuss the excitation spectra around the Dirac node on a surface of a three-dimensional topological insulator. By using the diagrammatic expansion, we show that the coupling of an electron with the gauge field in the presence of…

Mesoscale and Nanoscale Physics · Physics 2013-05-09 Tetsuro Habe , Yasuhiro Asano

It is shown that, contrary to the naive expectation, single particle spectral gaps can be opened on the surface states of three dimensional topological insulators by using commensurate out- and in-plane antiferromagnetic or ferrimagnetic…

Materials Science · Physics 2015-03-20 László Oroszlány , Alberto Cortijo

In this paper we present an approach for the generalization of adsorption of light gases in porous materials. This new theory goes beyond the Langmuir and BET theories, which are the standard approaches that have limited application to…

Materials Science · Physics 2018-03-28 Alexander A. Aduenko , Andy Murray , Jose L. Mendoza-Cortes

This monograph offers an overview on the topological invariants in fermionic topological insulators from the complex classes. Tools from K-theory and non-commutative geometry are used to define bulk and boundary invariants, to establish the…

Mathematical Physics · Physics 2016-02-17 Emil Prodan , Hermann Schulz-Baldes

We consider a junction between surface $p$-type and surface $n$-type on an ideal topological insulator in which carrier type and density in two adjacent regions are locally controlled by composition graded doping or electrical gating. Such…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Jing Wang , Xi Chen , Bang-Fen Zhu , Shou-Cheng Zhang