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Related papers: Topological Valley Currents in Gapped Dirac Materi…

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Graphene on hexagonal boron nitride (hBN) can exhibit a topological phase via mutual crystallographic alignment. Recent measurements of nonlocal resistance ($R_{nl}$) near the secondary Dirac point (SDP) in ballistic graphene/hBN…

Mesoscale and Nanoscale Physics · Physics 2020-12-21 Yang Li , Mario Amado , Timo Hyart , Grzegorz P. Mazur , Jason W. A. Robinson

Using first-principles density functional theory calculations, combined with a topological analysis, we have investigated the electronic properties of $Cd_3As_2$ and $Na_3Bi$ Dirac topological semimetals doped with non-magnetic and magnetic…

Strongly Correlated Electrons · Physics 2020-11-18 A. Rancati , N. Pournaghavi , M. F. Islam , A. Debernardi , C. M. Canali

We analyze the magneto-optical conductivity (and related magnitudes like transmittance and Faraday rotation of the irradiated polarized light) of some elemental two-dimensional Dirac materials of group IV (graphene analogues, buckled…

Mesoscale and Nanoscale Physics · Physics 2024-03-20 M. Calixto , A. Mayorgas , N. A. Cordero , E. Romera , O. Castaños

Valleytronics has emerged as a promising paradigm, enabling comprehensive control of the valley degree of freedom (DoF) for energy-efficient and high-speed information processing. However, backscattering-induced valley depolarization…

Valley, the energy extrema in the electronic band structure at momentum space, is regarded as a new degree of freedom of electrons, in addition to charge and spin. The studies focused on valley degree of freedom now form an emerging field…

Materials Science · Physics 2020-02-13 He Hu , Wen-Yi Tong , Yu-Hao Shen , Xiangang Wan , Chun-Gang Duan

We present an exact solution of a modifed Dirac equation for topological insulator in the presence of a hole or vacancy to demonstrate that vacancies may induce bound states in the band gap of topological insulators. They arise due to the…

Mesoscale and Nanoscale Physics · Physics 2011-07-22 Wen-Yu Shan , Jie Lu , Hai-Zhou Lu , Shun-Qing Shen

Recent pump-probe experiments demonstrate the possibility that Dirac materials may be driven into transient excited states describable by two chemical potentials, one for the electrons and one for the holes. Given the Dirac nature of the…

Materials Science · Physics 2017-05-10 Christopher Triola , Anna Pertsova , Robert S. Markiewicz , Alexander V. Balatsky

The application of a perpendicular electric field can drive silicene into a gapless state, characterized by two nearly fully spin-polarized Dirac cones owing to both relatively large spin-orbital interactions and inversion symmetry…

Mesoscale and Nanoscale Physics · Physics 2013-09-30 Yan-Yang Zhang , Wei-Feng Tsai , Kai Chang , X. -T. An , G. -P. Zhang , X. -C. Xie , Shu-Shen Li

It has been recently established that a nonlinear valley current could be generated through traveling a surface acoustic wave (SAW) in two-dimensional Dirac materials. So far, the SAW-driven valley currents have been attributed to warping…

Mesoscale and Nanoscale Physics · Physics 2024-04-03 Jia-Liang Wan , Ying-Li Wu , Ke-Qiu Chen , Xiao-Qin Yu

Dirac semimetals, the materials featured with discrete linearly crossing points (called Dirac points) between four bands, are critical states of topologically distinct phases. Such gapless topological states have been accomplished by a…

Materials Science · Physics 2020-01-20 Xiangxi Cai , Liping Ye , Chunyin Qiu , Meng Xiao , Rui Yu , Manzhu Ke , Zhengyou Liu

Gapped bilayer graphene can support the presence of intragap states due to kink gate potentials applied to the graphene layers. Electrons in these states display valley-momentum locking, which makes them attractive for topological…

Mesoscale and Nanoscale Physics · Physics 2022-02-17 Nassima Benchtaber , David Sánchez , Llorenç Serra

Semi-Dirac materials in 2D present an anisotropic dispersion relation, linear along one direction and quadratic along the perpendicular one. This study explores the topological properties and the influence of disorder in a 2D semi-Dirac…

Mesoscale and Nanoscale Physics · Physics 2024-06-13 Marta García Olmos , Yuriko Baba , Mario Amado , Rafael A. Molina

The 2D TI edge states are considered within the Volkov-Pankratov (VP) Hamiltonian. A smooth transition between TI and OI is assumed. The edge states are formed in the total gap of homogeneous 2D material. A pair of these states are of…

Mesoscale and Nanoscale Physics · Physics 2021-01-14 M. M. Mahmoodian , M. V. Entin

Recently discovered valley photonic crystals (VPCs) mimic many of the unusual properties of two-dimensional gapped valleytronic materials such as bilayer graphene or MoS2. Of the utmost interest to optical communications is their ability to…

Two-dimensional (2D) topological electronic insulators are known to give rise to gapless edge modes, which underlie low energy dynamics, including electrical and thermal transport. This has been thoroughly investigated in the context of…

Mesoscale and Nanoscale Physics · Physics 2022-05-10 Udit Khanna , Yuval Gefen , Ora Entin-Wohlman , Amnon Aharony

Topological insulators (TIs) are a new class of matter characterized by the unique electronic properties of an insulating bulk and metallic boundaries arising from non-trivial bulk band topology. While the surfaces of TIs have been well…

Materials Science · Physics 2014-10-09 L. Seixas , D. West , A. Fazzio , S. B. Zhang

We study the electromagnetic response and surface electromagnetic modes in a generic gapped Dirac material under pumping with circularly polarized light. The valley imbalance due to pumping leads to a net Berry curvature, giving rise to a…

Mesoscale and Nanoscale Physics · Physics 2017-07-10 Anshuman Kumar , Andrei Nemilentsau , Kin Hung Fung , George Hanson , Nicholas X. Fang , Tony Low

Topological insulators are most frequently constructed using lattices with specific degeneracies in their linear spectra, such as Dirac points. For a broad class of lattices, such as honeycomb ones, these points and associated Dirac cones…

Optics · Physics 2024-09-09 Hua Zhong , Yaroslav V. Kartashov , Yongdong Li , Ming Li , Yiqi Zhang

Ballistically propagating topologically protected states harbor exotic transport phenomena of wide interest. Here we describe a nontopological mechanism that produces such states at the surfaces of generic Dirac materials, giving rise to…

Mesoscale and Nanoscale Physics · Physics 2018-05-25 Oles Shtanko , Leonid Levitov

Topological nodal superconductors possess gapless low energy excitations that are characterized by point or line nodal Fermi surfaces. In this work, using a coupled wire construction, we study topological nodal superconductors that have…

Strongly Correlated Electrons · Physics 2018-11-28 Moon Jip Park , Syed Raza , Matthew J. Gilbert , Jeffrey C. Y. Teo