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Related papers: Valley filtering in strain-induced $\alpha$-$\math…

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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

Valley filters are crucial to any device exploiting the valley degree of freedom. By using an atomistic model, we analyze the mechanism leading to the valley filtering produced by a line-defect in graphene and show how it can be inverted by…

Mesoscale and Nanoscale Physics · Physics 2016-10-11 Lucas H. Ingaramo , Luis E. F. Foa Torres

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

Valley-polarized currents can be generated by local straining of multi-terminal graphene devices. The pseudo-magnetic field created by the deformation allows electrons from only one valley to transmit and a current of electrons from a…

Mesoscale and Nanoscale Physics · Physics 2016-11-18 S. P. Milovanovic , F. M. Peeters

In solid, the crystalline structure can endow electron an internal degree of freedom known as valley, which characterizes the degenerate energy minima in momentum space. The recent success in optical pumping of valley polarization in 2D…

Mesoscale and Nanoscale Physics · Physics 2017-03-07 Xing-Tao An , Jiang Xiao , M. W. -Y. Tu , Hongyi Yu , Vladimir I. Fal'ko , Wang Yao

We recently shown, using tight-binding calculations, that nonequilibrium valley polarization can be realized in graphene, when the current is injected through "valley filter": a ballistic point contact with zigzag edges. Here we…

Mesoscale and Nanoscale Physics · Physics 2008-05-23 Adam Rycerz

Here we theoretically investigate the valley-dependent transmission of particles through a combined electric and magnetic barrier in the $\alpha-T_3$ model which interpolates between the honeycomb and the dice lattices. We put forward that…

Mesoscale and Nanoscale Physics · Physics 2020-09-02 F. Bouhadida , L. Mandhour , S. Charfi-Kaddour

Realistic relaxed configurations of triaxially strained graphene quantum dots are obtained from unbiased atomistic mechanical simulations. The local electronic structure and quantum transport characteristics of y-junctions based on such…

Mesoscale and Nanoscale Physics · Physics 2013-06-20 Zenan Qi , D. A. Bahamon , Vitor M. Pereira , Harold S. Park , D. K. Campbell , A. H. Castro Neto

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

It is known that the lowest propagating mode in a narrow ballistic ribbon of graphene may lack the twofold valley degeneracy of higher modes. Depending on the crystallographic orientation of the ribbon axis, the lowest mode mixes both…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 A. Rycerz , J. Tworzydlo , C. W. J. Beenakker

The application of a mechanical strain to a 2D material can create pseudo-magnetic fields and lead to a quantized valley Hall effect. However, measuring valley-resolved effects remains a challenging task due to their inherent fragility and…

Mesoscale and Nanoscale Physics · Physics 2023-09-25 Maxime Jamotte , Lucila Peralta Gavensky , Cristiane Morais Smith , Marco Di Liberto , Nathan Goldman

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

We present the theory and measurement of valley splitting in a quantum point contact (QPC) in a modulation doped Si/SiGe heterostructure. Our measurements are performed on a submicron Schottky-gated device. An effective mass theory is…

Mesoscale and Nanoscale Physics · Physics 2010-03-30 L. M. McGuire , Mark Friesen , K. A. Slinker , S. N. Coppersmith , M. A. Eriksson

We devise a platform for noise-resistant quantum computing using the valley degree of freedom of Si quantum dots. The qubit is encoded in two polarized (1,1) spin-triplet states with different valley compositions in a double quantum dot,…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 Dimitrie Culcer , A. L. Saraiva , Belita Koiller , Xuedong Hu , S. Das Sarma

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

Intrinsic and extrinsic valley Hall effects are predicted to emerge in graphene systems with uniform or spatially-varying mass terms. Extrinsic mechanisms, mediated by the valley-dependent scattering of electrons at the Fermi surface, can…

Mesoscale and Nanoscale Physics · Physics 2021-07-07 Fionnuala Solomon , Stephen R. Power

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

Valleytronics and valley photonics exploit the valley degree of freedom to encode and manipulate information. Here we show that photonic valleys can be selectively addressed in quantum optics using a simple two-level emitter, provided it is…

Strain is extensively used to controllably tailor the electronic properties of materials. In the context of indirect band-gap semiconductors such as silicon, strain lifts the valley degeneracy of the six conduction band minima, and by…

This work performs a numerical study of electron transport through the fundamental logic gate in valleytronics - a valley valve consisting of two or increasing number of valley filters. Various typical effects on the transport are…

Mesoscale and Nanoscale Physics · Physics 2022-11-09 Jia-Huei Jiang , Ning-Yuan Lue , Feng-Wu Chen , Yu-Shu G. Wu
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