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Related papers: Graphene valley filter using a line defect

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An analogue of the Datta-Das spin FET is investigated, which is all-graphene and based on the valley degree of freedom of electrons / holes. The "valley FET" envisioned consists of a quantum wire of gapped graphene (channel) sandwiched…

Mesoscale and Nanoscale Physics · Physics 2013-01-01 M. -K. Lee , N. -Y. Lue , Y. -C. Chen , C. -K. Wen , G. Y. Wu

Graphene has recently been shown to possess giant nonlinearity; however, the utility of this nonlinearity is limited due to high losses and small interaction volume. We show that by performing waveguide engineering to graphene's…

Mesoscale and Nanoscale Physics · Physics 2014-11-19 Kelvin J. A. Ooi , Lay Kee Ang , Dawn T. H. Tan

We theoretically study valley-filtering in pristine graphene irradiated by bicircular counter-rotating laser drive. The dynamical symmetry of the graphene and laser drive disrupts graphene's inversion symmetry, which results distinct…

Mesoscale and Nanoscale Physics · Physics 2024-01-23 Rekha Kumari , Gopal Dixit , Arijit Kundu

Modulation of electronic states in two-dimensional (2D) materials can be achieved by using in-plane variations of the band gap or the average potential in lateral quantum structures. In the atomic configurations with hexagonal symmetry,…

Mesoscale and Nanoscale Physics · Physics 2016-08-10 Feng-Wu Chen , Mei-Yin Chou , Yiing-Rei Chen , Yu-Shu Wu

Propagation of an electron wave packet through a quantum point contact (QPC) defined by electrostatic gates in bilayer graphene is investigated. The gates provide a bias between the layers, in order to produce an energy gap. If the gates on…

Mesoscale and Nanoscale Physics · Physics 2016-01-05 D. R. da Costa , A. Chaves , S. H. R. Sena , G. A. Farias , F. M. Peeters

The low energy band structure of graphene has two inequivalent valleys at K and K' points of the Brillouin zone. The possibility to manipulate this valley degree of freedom defines the field of valleytronics, the valley analogue of…

Mesoscale and Nanoscale Physics · Physics 2017-01-11 Mikkel Settnes , Stephen R. Power , Mads Brandbyge , Antti-Pekka Jauho

Kelvin probe force microscopy (KPFM) has been employed to probe charge carriers in a graphene/hexagonal boron nitride (hBN) heterostructure [Nano Lett, 21, 5013 (2021)]. We propose an approach for operating valley filtering based on the…

Mesoscale and Nanoscale Physics · Physics 2023-10-19 A. Belayadi , N. A. Hadadi , P. Vasilopoulos , A. Abbout

We consider tunneling transport between two parallel graphene sheets where one is a single-layer sample and the other one a bilayer. In the presence of an in-plane magnetic field, the interplay between combined energy and momentum…

Mesoscale and Nanoscale Physics · Physics 2014-02-25 L Pratley , U. Zuelicke

The possibility to effect valley splitting of an electronic current in graphene represents the essential component in the new field of valleytronics in such two-dimensional materials. Based on a symmetry analysis of the scattering matrix,…

Mesoscale and Nanoscale Physics · Physics 2017-11-22 Mahmoud M. Asmar , Sergio E. Ulloa

Elastic deformations of graphene can significantly change the flow paths and valley polarization of the electric currents. We investigate these phenomena in graphene nanoribbons with localized out-of-plane deformations by means of…

Mesoscale and Nanoscale Physics · Physics 2019-03-12 Thomas Stegmann , Nikodem Szpak

A valley filter capable of generating a valley-polarized current is a crucial element in valleytronics, yet its implementation remains challenging. Here, we propose a valley filter made of a graphene bilayer which exhibits a 1D moir\'{e}…

Mesoscale and Nanoscale Physics · Physics 2024-04-19 Kai Shao , Hao Geng , Erfu Liu , Jose L. Lado , Wei Chen , D. Y. Xing

Valley filtering processes have been explored in different graphene-based configurations and scenarios to control transport responses. Here we propose graphene multi-terminal set-ups properly designed to obtain valley filtered currents in a…

Mesoscale and Nanoscale Physics · Physics 2021-03-31 Vanessa Torres , Daiara Faria , Andrea Latgé

We study quasi-particle transmission through an $n $-$p$ junction in a graphene irradiated by an electromagnetic field (EF). In the absence of EF the electronic spectrum of undoped graphene is gapless, and one may expect the perfect…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 M. V. Fistul , K. B. Efetov

Due to their possibility to encode information and realize low-energy-consumption quantum devices, control and manipulation of the valley degree of freedom have been widely studied in electronic systems. In contrast, the phononic…

Mesoscale and Nanoscale Physics · Physics 2019-02-25 Xiaobin Chen , Yong Xu , Jian Wang , Hong Guo

The extreme mechanical resilience of graphene and the peculiar coupling it hosts between lattice and electronic degrees of freedom have spawned a strong impetus towards strain-engineered graphene where, on the one hand, strain augments the…

Mesoscale and Nanoscale Physics · Physics 2017-08-16 Gareth W. Jones , D. A. Bahamon , A. H. Castro Neto , Vitor M. Pereira

We consider electron transport in a planar fermion model containing various types of line defects modelled by $\delta$--function pseudopotentials with different matrix coefficients. The transmission probability for electron transport…

Mesoscale and Nanoscale Physics · Physics 2014-02-14 D. Ebert , V. Ch. Zhukovsky , E. A. Stepanov

Graphene is a very promising test-bed for the field of electron quantum optics. However, a fully tunable and coherent electronic beam splitter is still missing. We report the demonstration of electronic beam splitters in graphene that…

The existence of nontrivial Berry phases associated with two inequivalent valleys in graphene provides interesting opportunities for investigating the valley-projected topological states. Examples of such studies include observation of…

Mesoscale and Nanoscale Physics · Physics 2020-05-13 C. -C. Hsu , M. L. Teague , J. -Q. Wang , N. -C. Yeh

We analyze the problem of electronic transmission through different regions of a graphene sheet that are characterized by different types of connections between the Dirac points. These valley symmetry breaking Hamiltonians might arise from…

Mesoscale and Nanoscale Physics · Physics 2015-09-17 Pedro L. S. Lopes , A. H. Castro Neto , A. O. Caldeira

We show that the optical excitation of graphene with polarized light leads to the pure valley current where carriers in the valleys counterflow. The current in each valley originates from asymmetry of optical transitions and electron…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 L. E. Golub , S. A. Tarasenko , M. V. Entin , L. I. Magarill