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Related papers: Valley filtering by a line-defect in graphene: qua…

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Valley polarization in graphene breaks inversion symmetry and therefore leads to second-harmonic generation. We present a complete theory of this effect within a single-particle approximation. It is shown that this may be a sensitive tool…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 T. O. Wehling , A. Huber , A. I. Lichtenstein , M. I. Katsnelson

We propose an all-electrical setup to generate valley polarization in graphene. A finite graphene sheet is connected to two normal metal electrodes each with two terminals along its zigzag edges, while the armchair edges remain free. When a…

Mesoscale and Nanoscale Physics · Physics 2025-06-30 Sachchidanand Das , Abhiram Soori

Valley degrees of freedom, providing a novel way to increase capacity and efficiency of information processing, have become an important instrument for photonics. Experimental studies on photonic topological valley kink states at interfaces…

Graphene subject to high levels of shear strain leads to strong pseudo-magnetic fields resulting in the emergence of Landau levels. Here we show that, with modest levels of strain, graphene can also sustain a classical valley hall effect…

Mesoscale and Nanoscale Physics · Physics 2017-03-01 Xian-Peng Zhang , Chunli Huang , Miguel A. Cazalilla

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

We investigate physical properties that can be used to distinguish the valley degree of freedom in systems where inversion symmetry is broken, using graphene systems as examples. We show that the pseudospin associated with the valley index…

Materials Science · Physics 2011-11-10 Di Xiao , Wang Yao , Qian Niu

We theoretically investigate gate-defined graphene superlattices with broken inversion symmetry as a platform for realizing tunable valley dependent transport. Our analysis is motivated by recent experiments [C. Forsythe et al., Nat.…

Mesoscale and Nanoscale Physics · Physics 2019-10-21 Johannes H. J. Martiny , Kristen Kaasbjerg , Antti-Pekka Jauho

The electronic conductance of graphene-based bilayer flake systems reveal different quantum interference effects, such as Fabry-P\'erot resonances and sharp Fano antiresonances on account of competing electronic paths through the device.…

Mesoscale and Nanoscale Physics · Physics 2017-01-18 D. Zambrano , L. Rosales , A. Latgé , M. Pacheco , P. A. Orellana

Dirac-electronic tunneling and nonlinear transport properties with both finite and zero energy bandgap are investigated for graphene with a tilted potential barrier under a bias. For validation, results from a finite-difference based…

Mesoscale and Nanoscale Physics · Physics 2020-04-01 Farhana Anwar , Andrii Iurov , Danhong Huang , Godfrey Gumbs , Ashwani Sharma

Mechanical deformations in $\alpha$-$\mathcal{T}_3$ lattices induce local pseudomagnetic fields of opposite directionality for different valleys. When this strain is equipped with a dynamical drive, it generates a complementary…

Mesoscale and Nanoscale Physics · Physics 2022-12-07 Alexander Filusch , Holger Fehske

We consider systems described by the two-dimensional Dirac equation where the Fermi velocity is inhomogeneous as a consequence of mechanical deformations. We show that the mechanical deformations can lead to deflection and focusing of the…

Mesoscale and Nanoscale Physics · Physics 2021-11-23 Alonso Contreras-Astorga , Vit Jakubsky , Alfredo Raya

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 observation of large nonlocal resistances near the Dirac point in graphene has been related to a variety of intrinsic Hall effects, where the spin or valley degrees of freedom are controlled by symmetry breaking mechanisms. Engineering…

Mesoscale and Nanoscale Physics · Physics 2019-11-15 Mário Ribeiro , Stephen R. Power , Stephan Roche , Luis. E. Hueso , Fèlix Casanova

We study graphene with an adsorbed spin texture, where the localized spins create a periodic magnetic flux. The latter produces gaps in the graphene spectrum and breaks the valley symmetry. The resulting effective electronic model, which is…

Materials Science · Physics 2011-03-31 Antonio Hill , Andreas Sinner , Klaus Ziegler

We study the role of electronic spin and valley symmetry in the quantum interference (QI) patterns of the transmission function in graphene quantum junctions. In particular, we link it to the position of the destructive QI anti-resonances.…

Strongly Correlated Electrons · Physics 2019-08-21 Angelo Valli , Adriano Amaricci , Valentina Brosco , Massimo Capone

When graphene is deformed in a dynamical manner, a time-dependent potential is induced for the electrons. The potential is antisymmetric with respect to valleys, and some straightforward applications are found for Raman spectroscopy. We…

Mesoscale and Nanoscale Physics · Physics 2014-11-17 Ken-ichi Sasaki , Yasuhiro Tokura , Hideki Gotoh

This work investigates the feasibility of electrical valley filtering for holes in transition metal dichalcogenides. We look specifically into the scheme that utilizes a potential barrier to produce valley-dependent tunneling rates, and…

Mesoscale and Nanoscale Physics · Physics 2020-05-12 Tzu-Chi Hsieh , Mei-Yin Chou , Yu-Shu Wu

Ballistic point contact (BPC) with zigzag edges in graphene is a main candidate of a valley filter, in which the polarization of the valley degree of freedom can be selected by using a local gate voltage. Here, we propose to detect the…

Mesoscale and Nanoscale Physics · Physics 2017-12-27 Kun Luo , Tao Zhou , Wei Chen

The valley transport properties of a superlattice of out-of-plane Gaussians deformations are calculated using a Green's function and a Machine Learning approach. Our results show that periodicity significantly improves the valley filter…

Mesoscale and Nanoscale Physics · Physics 2019-11-14 V. Torres , P. Silva , E. A. T. de Souza , L. A. Silva , D. A. Bahamon

Dirac electrons in graphene have a valley degree of freedom that is being explored as a carrier of information. In that context of "valleytronics" one seeks to coherently manipulate the valley index. Here we show that reflection from a…

Mesoscale and Nanoscale Physics · Physics 2018-09-12 C. W. J. Beenakker , N. V. Gnezdilov , E. Dresselhaus , V. P. Ostroukh , Y. Herasymenko , I. Adagideli , J. Tworzydlo