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Related papers: Two-dimension Dirac fermions system in CdHgTe quan…

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Topological semimetals with massless Dirac and Weyl fermions represent the forefront of quantum materials research. In two dimensions (2D), a peculiar class of fermions that are massless in one direction and massive in the perpendicular…

A well known semiconductor Cd3As2 has reentered the spotlight due to its unique electronic structure and quantum transport phenomena as a topological Dirac semimetal. For elucidating and controlling its topological quantum state,…

Topological insulators are electronic materials that have a bulk band gap like an ordinary insulator, but have protected conducting states on their edge or surface. The 2D topological insulator is a quantum spin Hall insulator, which is a…

Mesoscale and Nanoscale Physics · Physics 2015-03-13 M. Z. Hasan , C. L. Kane

Topological insulators are transformative quantum solids with immune-to-disorder metallic surface states having Dirac band structure. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to…

Low energy excitation of surface states of a three-dimensional topological insulator (3DTI) can be described by Dirac fermions. By using a tight-binding model, the transport properties of the surface states in a uniform magnetic field is…

Mesoscale and Nanoscale Physics · Physics 2012-01-16 Yan-Yang Zhang , Xiang-Rong Wang , X. C. Xie

Topological superconductors are an intriguing and elusive quantum phase, characterized by topologically protected gapless surface/edge states residing in a bulk superconducting gap, which hosts Majorana fermions. Unfortunately, all…

Superconductivity · Physics 2019-05-10 Kyung-Hwan Jin , Huaqing Huang , Jia-Wei Mei , Zheng Liu , Lih-King Lim , Feng Liu

We demonstrate evidences of electronic transport via topological Dirac surface states in a thin film of strained HgTe. At high perpendicular magnetic fields, we show that the electron transport reaches the quantum Hall regime with vanishing…

Mesoscale and Nanoscale Physics · Physics 2017-12-27 C. Thomas , O. Crauste , B. Haas , P. H. Jouneau , C. Bäuerle , L. P. Lévy , E. Orignac , D. Carpentier , P. Ballet , T. Meunier

We investigated the magnetotransport properties of strained, 80nm thick HgTe layers featuring a high mobility of mu =4x10^5 cm^2/Vs. By means of a top gate the Fermi-energy is tuned from the valence band through the Dirac type surface…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 D. A. Kozlov , Z. D. Kvon , D. Weiss , E. B. Olshanetsky , N. N. Mikhailov , S. A. Dvoretsky

We calculate the tunneling density-of-states (DOS) of a disorder-free two-dimensional interacting electron system with a massless-Dirac band Hamiltonian. The DOS exhibits two main features: i) linear growth at large energies with a slope…

Mesoscale and Nanoscale Physics · Physics 2012-07-10 A. Principi , Marco Polini , Reza Asgari , A. H. MacDonald

The surface states of topological insulators, which behave as charged massless Dirac fermions, are studied in the presence of a quantizing uniform magnetic field. Using the method of D.H. Lee[1], analytical formula satisfied by the energy…

Mesoscale and Nanoscale Physics · Physics 2011-12-13 Oskar Vafek

The HgTe quantum well (QW) is a well-characterized two-dimensional topological insulator (2D-TI). Its band gap is relatively small (typically on the order of 10 meV), which restricts the observation of purely topological conductance to low…

Materials Science · Physics 2016-08-24 Philipp Leubner , Lukas Lunczer , Christoph Brüne , Hartmut Buhmann , Laurens W. Molenkamp

We investigate theoretically the cavity quantum electrodynamics of the cyclotron transition for Dirac fermions in graphene. We show that the ultrastrong coupling regime characterized by a vacuum Rabi frequency comparable or even larger than…

Mesoscale and Nanoscale Physics · Physics 2015-06-03 David Hagenmüller , Cristiano Ciuti

Based on the first-principles calculations, we recover the silent topological nature of Cd3As2, a well known semiconductor with high carrier mobility. We find that it is a symmetry-protected topological semimetal with a single pair of…

Materials Science · Physics 2014-04-21 Zhijun Wang , Hongming Weng , Quansheng Wu , Xi Dai , Zhong Fang

We present a scheme to realize the chiral topological excitonic insulator in semiconductor heterostructures which can be experimentally fabricated with a coupled quantum well adjacent to twoferromagnetic insulating films. The different…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Ningning Hao , Ping Zhang , Jian Li , Zhigang Wang , Wei Zhang , Yupeng Wang

HgTe quantum wells with a thickness of ${\sim}$7 nm may have a graphene-like band structure and have been recently proposed to be potential candidates for quantum Hall effect (QHE) resistance standards under the condition of operation in…

We show the existence of massive Dirac fermions in electronic band structures of a few Fe atomic layers with perpendicular magnetization. Based on a tight binding model fitted to ab-initio band structure, we observe four distinct massive…

Materials Science · Physics 2015-09-24 Xiao-Tian Zhang , Baolong Xu , Kohji Nakamura , Ryuichi Shindou

Topological semimetals, such as Dirac, Weyl, or line-node semimetals, are gapless states of matter characterized by their nodal band structures and surface states. In this work, we consider layered (topologically trivial) insulating systems…

Mesoscale and Nanoscale Physics · Physics 2022-05-12 Saavanth Velury , Taylor L. Hughes

We address the problem of Dirac fermions graphene quantum well and we focus on the low energy approximation for the Hamiltonian of the system where the former can be described by a Dirac-like Hamiltonian. Interesting relations are obtained…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 A. Mhamdi , E. Ben Salem , S. Jaziri

We have studied the fractional quantum Hall states on the surface of a topological insulator thin film in an external magnetic field, where the Dirac fermion nature of the charge carriers have been experimentally established only recently.…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 Vadim M. Apalkov , Tapash Chakraborty

Condensed matter systems provide a rich setting to realize Dirac and Majorana fermionic excitations and the possibility to manipulate them in materials for potential applications. Recently, it has been proposed that Weyl fermions, which are…