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Graphene photonics has emerged as a promising platform for providing desirable optical functionality. However, graphene's monolayer-scale thickness fundamentally restricts the available light matter interaction, posing a critical design…

Optics · Physics 2017-05-11 PoHan Chang , Charles Lin , Amr S. Helmy

We study the tunneling of chiral electrons in graphene through a region where the electronic spectrum changes from the usual linear dispersion to a hyperbolic dispersion, due to the presence of a gap. It is shown that contrary to the…

Mesoscale and Nanoscale Physics · Physics 2008-07-09 J. Viana Gomes , N. M. R. Peres

We investigated the Dirac electrons transmission through a potential barrier in the presence of circularly polarized light. An anomalous photon-assisted enhanced transmission is predicted and explained in a comparison with the well-known…

Materials Science · Physics 2015-05-30 Andrii Iurov , Godfrey Gumbs , Oleksiy Roslyak , Danhong Huang

Using the coupled-mode theory in guided-wave optics and electronics, we explore a directional coupling structure composed of two parallel waveguides electrostatically induced by the split-gate technique in bulk graphene. Our results show…

Mesoscale and Nanoscale Physics · Physics 2011-03-29 L. Zhao , Wenhui Duan

We study the charge density distribution, the electric field profile, and the resistance of an electrostatically created lateral p-n junction in graphene. We show that the electric field at the interface of the electron and hole regions is…

Mesoscale and Nanoscale Physics · Physics 2008-03-22 L. M. Zhang , M. M. Fogler

Electron supercollimation, in which a wavepacket is guided to move undistorted along a selected direction, is a highly desirable property that has yet been realized experimentally. Disorder in general is expected to inhibit…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 SangKook Choi , Cheol-Hwan Park , Steven G. Louie

This work analyzes monolayer graphene in external electromagnetic fields, which is described by the Dirac equation with minimal coupling. Supersymmetric quantum mechanics allows building new Dirac equations with modified magnetic fields.…

Mesoscale and Nanoscale Physics · Physics 2022-09-07 Miguel Castillo-Celeita , Alonso Contreras-Astorga , David J. Fernández C

Laser-plasma technology promises a drastic reduction of the size of high energy electron accelerators. It could make free electron lasers available to a broad scientific community, and push further the limits of electron accelerators for…

We analyze nonlinear optics schemes for generating pairs of quantum entangled plasmons in the terahertz-infrared range in graphene. We predict that high plasmonic field concentration and strong optical nonlinearity of monolayer graphene…

Mesoscale and Nanoscale Physics · Physics 2022-06-17 Zhiyuan Sun , D. N. Basov , M. M. Fogler

Free electrons moving in an optical standing wave field feel the ponderomotive potential, acting as a refractive-index medium in electron optics. Emerging technologies involving this potential have been proposed and realized in electron…

Optics · Physics 2022-01-25 Yuuki Uesugi , Yuichi Kozawa , Shunichi Sato

Exerting well-defined control over the reflection $(R)$, absorption $(A)$, and transmission $(T)$ of electromagnetic waves is a key objective in quantum optics. To this end, one often utilizes hybrid structures comprised of elements with…

Optics · Physics 2016-12-06 Jacob Linder , Klaus Halterman

Spatio-temporal shaping of electron beams is a bold frontier in electron microscopy, enabling new routes toward spatial-resolution enhancement, selective probing, low-dose imaging and faster data acquisition. Over the last decade, shaping…

Nonlinear optical processes rely on the intrinsically weak interactions between photons enabled by their coupling with matter. Unfortunately, many applications in nonlinear optics are severely hindered by the small response of conventional…

Materials Science · Physics 2014-12-15 Joel D. Cox , F. J. Garcia de Abajo

We study the electronic structure of Dirac fermions scattered by double barrier potential in graphene under strain effect. We show that traction and compression strains can be used to generate fermion beam collimation, 1D channels, surface…

Mesoscale and Nanoscale Physics · Physics 2019-07-01 El Bouâzzaoui Choubabi , Abdellatif Kamal , Ahmed Jellal , Hocine Bahlouli

Here we demonstrate the selective bulk scale synthesis of delaminated graphene sheets by a proper choice of magnetic field modulating an electric-arc. An ultra-high purity glassy graphite anode was sublimated in an argon atmosphere. Carbon…

Graphene is at the center of a significant research effort. Near-ballistic transport at room temperature and high mobility make it a potential material for nanoelectronics. Its electronic and mechanical properties are also ideal for micro…

Materials Science · Physics 2010-03-03 Z. Sun , T. Hasan , F. Torrisi , D. Popa , G. Privitera , F. Wang , F. Bonaccorso , D. M. Basko , A. C. Ferrari

A non-perturbative model for graphene optical nonlinearity is developed for the study of ultrafast pulse propagation along a monolayer, as in the case of graphene-comprising nanophotonic integrated waveguides. This graphene `hot electron'…

Optics · Physics 2022-03-18 Alexandros Pitilakis , Emmanouil E. Kriezis

Ballistic heterojunctions of Dirac materials offer the opportunity of exploring optics-like phenomena in electronic systems. In this paper, a new perfect lens through special positive refraction is predicted with omnidirectional Klein…

Materials Science · Physics 2018-10-08 Y. Betancur-Ocampo

We analyze theoretically 4-terminal electronic devices composed of two crossed graphene nanoribbons (GNRs) and show that they can function as beam splitters or mirrors. These features are identified for electrons in the low-energy region…

Mesoscale and Nanoscale Physics · Physics 2020-07-28 Sofia Sanz , Pedro Brandimarte , Géza Giedke , Daniel Sánchez-Portal , Thomas Frederiksen

The absence of a band-gap in graphene limits the gate modulation of its electron conductivity, both in regular graphene as well as in PN junctions, where electrostatic barriers prove transparent to Klein tunneling. We demonstrate a novel…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 Redwan Sajjad , Avik Ghosh