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Generating discernible valley contrasts and segregating valley-indexed fermions in real space within graphene poses considerable challenges due to the isotropic transport within the continuum energy range for degenerate valleys. This study…

Mesoscale and Nanoscale Physics · Physics 2024-02-23 Shrushti Tapar , Bhaskaran Muralidharan

The rise of graphene opens a new door to qubit implementation, as discussed in the recent proposal of valley pair qubits in double quantum dots of gapped graphene (Wu et al., arXiv: 1104.0443 [cond-mat.mes-hall]). The work here presents the…

Mesoscale and Nanoscale Physics · Physics 2011-07-05 G. Y. Wu , N. -Y. Lue , L. Chang

We fabricate and investigate high quality graphene devices with contactless, suspended top gates, and demonstrate formation of graphene pnp junctions with tunable polarity and doping levels. The device resistance displays distinct…

Mesoscale and Nanoscale Physics · Physics 2011-08-12 Jairo Velasco , Gang Liu , Wenzhong Bao , Chun Ning Lau

We calculated the optical properties of an $N$-layer graphene by formulating the dynamical conductivity of each layer. This is the conductivity when an electromagnetic field is localized at a particular layer and differs from the standard…

Materials Science · Physics 2020-08-25 Ken-ichi Sasaki

The interplay of massive electrons with spin-orbit coupling in bulk graphene results in a spin-valley dependent gap. Thus, a barrier with such properties can act as a filter, transmitting only opposite spins from opposite valleys. In this…

Mesoscale and Nanoscale Physics · Physics 2014-07-25 Marko M. Grujić , Milan Ž. Tadić , François M. Peeters

Spatial manipulation of current flow in graphene could be achieved through the use of a tilted pn junction. We show through numerical simulation that a pseudo-Hall effect (i.e. non-equilibrium charge and current density accumulating along…

Mesoscale and Nanoscale Physics · Physics 2009-12-20 Tony Low , Joerg Appenzeller

We study the Andreev reflections and the quantum transport in the proximitized graphene/superconductor junction. The proximitized graphene possesses the pseudospin staggered potential and the intrinsic spin-orbit coupling induced by…

Mesoscale and Nanoscale Physics · Physics 2023-07-20 Lu Gao , Qiang Cheng , Qing-Feng Sun

We report on measurements of quantized conductance in gate-defined quantum point contacts in bilayer graphene that allow the observation of subband splittings due to spin-orbit coupling. The size of this splitting can be tuned from 40 to 80…

Mesoscale and Nanoscale Physics · Physics 2020-05-05 L. Banszerus , B. Frohn , T. Fabian , S. Somanchi , A. Epping , M. Müller , D. Neumaier , K. Watanabe , T. Taniguchi , F. Libisch , B. Beschoten , F. Hassler , C. Stampfer

We investigate charge transport of pn and npn junctions made from silicene, Si analogue of graphene. The conductance shows the distinct gate-voltage dependences peculiar to the topological and non-topological phases, where the topological…

Mesoscale and Nanoscale Physics · Physics 2013-09-12 Ai Yamakage , Motohiko Ezawa , Yukio Tanaka , Naoto Nagaosa

We demonstrate a tunneling and rectification behavior in bilayer graphene. A stepped dielectric top gate creates a spatially modulated electric field, which opens the band gap in the graphene and produces an insulating region at the p-n…

Mesoscale and Nanoscale Physics · Physics 2011-12-19 Hisao Miyazaki , Michael Lee , Song-Lin Li , Hidefumi Hiura , Kazuhito Tsukagoshi , Akinobu Kanda

The unusual electronic properties of single-layer graphene make it a promising material system for fundamental advances in physics, and an attractive platform for new device technologies. Graphene's spin transport properties are expected to…

Mesoscale and Nanoscale Physics · Physics 2009-10-23 Mark B. Lundeberg , Joshua A. Folk

The aim of this work is to describe the electronic properties of graphene in a constant magnetic field in the long wavelength approximation with random binary disorder, by solving the Soven equation self-consistently. Density of state…

Mesoscale and Nanoscale Physics · Physics 2015-03-03 Juan Sebastian Ardenghi , Pablo Bechthold , Estela Gonzalez , Paula Jasen , Alfredo Juan

Quantum transport calculations describing electron scattering off an extended line defect in graphene are presented. The calculations include potentials from local magnetic moments recently predicted to exist on sites adjacent to the line…

Mesoscale and Nanoscale Physics · Physics 2012-05-18 Daniel Gunlycke , Carter T. White

Graphene, and other members of the monolayer Xene family, represent an ideal materials platform for "valleytronics", the control of valley localized charge excitations. The absence of a gap in these semi-metals, however, precludes valley…

Transport measurement of electron optics in monolayer graphene p-n junction devices has been traditionally studied with negative refraction and chiral transmission experiments in Hallbar magnetic focusing set-ups. We show direct signatures…

Mesoscale and Nanoscale Physics · Physics 2022-10-20 Mirza M. Elahi , Yihang Zeng , Cory R. Dean , Avik W. Ghosh

The dynamic polarization for kekul\'e-patterned graphene is studied within the Random Phase Approximation (RPA). It is shown how the breaking of the valley degeneracy by the lattice modulation is manifested through the dielectric spectrum,…

Mesoscale and Nanoscale Physics · Physics 2020-12-03 Saúl A. Herrera , Gerardo G. Naumis

We show simultaneous p and n type carrier injection in bilayer graphene channel by varying the longitudinal bias across the channel and the top gate voltage. The top gate is applied electrochemically using solid polymer electrolyte and the…

Mesoscale and Nanoscale Physics · Physics 2009-09-08 Biswanath Chakraborty , Anindya Das , A. K. Sood

A valley plasmonic crystal for graphene surface plasmons (GSPs) is proposed. We demonstrate that a designer metagate, placed within a few nanometers from graphene, can be used to impose a triangular periodic Fermi energy landscape on the…

Mesoscale and Nanoscale Physics · Physics 2018-08-29 Minwoo Jung , Zhiyuan Fan , Gennady Shvets

The valley degeneracy of electron states in graphene stimulates intensive research of valley-related optical and transport phenomena. While many proposals on how to manipulate valley states have been put forward, experimental access to the…

Mesoscale and Nanoscale Physics · Physics 2014-11-17 L. E. Golub , S. A. Tarasenko

In bilayer graphene, electrostatic confinement can be realized by a suitable design of top and back gate electrodes. We measure electronic transport through a bilayer graphene quantum dot, which is laterally confined by gapped regions and…