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Related papers: Optical valleytronics of impurity states in two-di…

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Mode conversion of transverse electromagnetic waves into longitudinal oscillations and the associated resonant absorption of wave energy in inhomogeneous plasmas is a phenomenon that has been studied extensively in plasma physics. We show…

Mesoscale and Nanoscale Physics · Physics 2022-02-09 Kihong Kim , Seulong Kim

Altermagnets (AM) are a recently discovered third class of collinear magnets, and have been attracting significant interest in the field of condensed matter physics. Here, based on first-principles calculations and theoretical analysis, we…

Materials Science · Physics 2024-12-02 Jin-Yang Li , An-Dong Fan , Yong-Kun Wang , Ying Zhang , Si Li

We show that the inter-band absorption of radiation in a 2D Dirac material leads to a direct electric current flowing at sample edges. The photocurrent originates from the momentum alignment of electrons and holes and is controlled by the…

Mesoscale and Nanoscale Physics · Physics 2021-04-21 M. V. Durnev , S. A. Tarasenko

Inversion symmetry breaking allows contrasted circular dichroism in different k-space regions, which takes the extreme form of optical selection rules for interband transitions at high symmetry points. In materials where band-edges occur at…

Mesoscale and Nanoscale Physics · Physics 2008-06-05 Wang Yao , Di Xiao , Qian Niu

We explore the effect of valley-contrasting gaps in the optical response of two-dimensional anisotropic tilted Dirac systems. We study the spectrum of intraband and interband transitions through the joint density of states (JDOS), the…

Mesoscale and Nanoscale Physics · Physics 2021-04-21 M. A. Mojarro , R. Carrillo-Bastos , Jesús A. Maytorena

1T$^\prime$-MoS$_2$ exhibits valley-spin-polarized tilted Dirac bands in the presence of external vertical electric field and undergoes a topological phase transition between the topological insulator and band insulator around the critical…

Mesoscale and Nanoscale Physics · Physics 2021-04-01 Chao-Yang Tan , Chang-Xu Yan , Yong-Hong Zhao , Hong Guo , Hao-Ran Chang

Optical interband transitions in monolayer transition metal dichalcogenides such as WSe2 and MoS2 are governed by chiral selection rules. This allows efficient optical initialization of an electron in a specific K-valley in momentum space.…

Mesoscale and Nanoscale Physics · Physics 2014-09-09 G. Wang , L. Bouet , D. Lagarde , M. Vidal , A. Balocchi , T. Amand , X. Marie , B. Urbaszek

Electrons are offered a valley degree of freedom in presence of particular lattice structures. Manipulating valley degeneracy is the subject matter of an emerging field of investigation, mostly focused on charge transport in graphene. In…

Strongly Correlated Electrons · Physics 2012-04-18 Zengwei Zhu , Aurelie Collaudin , Benoit Fauque , Woun Kang , Kamran Behnia

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

Lifshitz transition is a kind of topological phase transition in which the Fermi surface is reconstructed. It can occur in the two-dimensional (2D) tilted Dirac materials when the energy bands change between the type-I phase ($0<t<1$) and…

Mesoscale and Nanoscale Physics · Physics 2022-10-10 Chao-Yang Tan , Jian-Tong Hou , Chang-Xu Yan , Hong Guo , Hao-Ran Chang

The valley dependent optical selection rules in recently discovered monolayer group-VI transition metal dichalcogenides (TMDs) make possible optical control of valley polarization, a crucial step towards valleytronic applications. However,…

Mesoscale and Nanoscale Physics · Physics 2014-07-31 Rui-Lin Chu , Xiao Li , Sanfeng Wu , Qian Niu , Wang Yao , Xiaodong Xu , Chuanwei Zhang

In many atomically thin materials their optical absorption is dominated by excitonic transitions. It was recently found that optical selection rules in these materials are influenced by the band topology near the valleys. We propose that…

Mesoscale and Nanoscale Physics · Physics 2020-10-12 Gaofeng Xu , Tong Zhou , Benedikt Scharf , Igor Žutić

Low-energy excitations in graphene exhibit relativistic properties due to the linear dispersion relation close to the Dirac points in the first Brillouin zone. Two of the Dirac points located at opposite corners of the first Brillouin zone…

Mesoscale and Nanoscale Physics · Physics 2017-05-25 T. Sekera , C. Bruder , E. J. Mele , R. P. Tiwari

Monolayers of transition metal dichalcogenides (TMDCs) are atomically thin direct-gap semiconductors with potential applications in nanoelectronics, optoelectronics, and electrochemical sensing. Recent theoretical and experimental efforts…

Mesoscale and Nanoscale Physics · Physics 2013-02-26 Sanfeng Wu , Chunming Huang , Grant Aivazian , Jason S Ross , David H Cobden , Xiaodong Xu

Valleytronics targets the exploitation of the additional degrees of freedom in materials where the energy of the carriers may assume several equal minimum values (valleys) at non-equivalent points of the reciprocal space. In single layers…

Advances of condensed matter physics in exploiting the spin degree of freedom of electrons led to the emergence of the field of spintronics, which envisions new and more efficient approaches to data transfer, computing, and storage [1-3].…

Bilayer Heisenberg ferromagnetic insulators hold degenerate terahertz Dirac magnon modes associated with two opposite valleys of the hexagonal Brillouin zone. We show that this energy degeneracy can be removed by breaking of the inversion…

Mesoscale and Nanoscale Physics · Physics 2020-08-25 Xuechao Zhai , Yaroslav M. Blanter

We present a theory of optical absorption by interlayer excitons in a heterobilayer formed from transition metal dichalcogenides. The theory accounts for the presence of small relative rotations that produce a momentum shift between…

Mesoscale and Nanoscale Physics · Physics 2018-01-24 Fengcheng Wu , Timothy Lovorn , A. H. MacDonald

The valley degree of freedom of electrons in materials promises routes toward energy-efficient information storage with enticing prospects towards quantum information processing. Current challenges in utilizing valley polarization are…

We study field-controlled spin-valley transport in monolayer MoS$_2$ through a single electrostatic barrier and a uniform off-resonant elliptically polarized irradiation. Starting from the massive Dirac Hamiltonian with intrinsic spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2026-05-21 Kamal Azaidaoui , Hocine Bahlouli , Clarence Cortes , David Laroze , Ahmed Jellal